Interval T1 Research Articles

The validity of dynamic block displacement prediction using DDA

In 1965, Newmark [1] published his classic Rankine lecture on ‘‘effects of earthquakes on dams and embankments’’. In his paper, Newmark presented solutions for displacement of a mass along circular or planar sliding surface under earthquake loading. Newmark made the assumption that the mass moves as a single rigid body with resistance mobilized along the sliding surface. Newmark further considered only a single pulse of magnitude Ag lasting for a time interval t0, arguing that introduction of a sinusoidal pulse would complicate the expressions unnecessarily. Thus, the socalled ‘‘Newmark method’’ provided an estimate for the amount of mass displacement to be expected under ground acceleration of constant magnitude and given duration. Newmark admitted that his approach would generally overestimate the actual displacement because it ignores the earthquake pulse in the opposite direction. Goodman and Seed [2] studied experimentally the shear resistance of sand to cyclic loading and suggested an expression for shear strength degradation as a function of displacement. They used numerical integration to find the velocity and displacement of a block on an incline subjected to a sinusoidal acceleration function of the form

Categorical Rhythm Perception as a Result of Unilateral Assimilation in Time-Shrinking

In previous studies, we established an illusion of time perception that we called time-shrinking: an empty time interval, immediately preceded by a slightly shorter time interval, is underestimated. In the first experiment of the present study, we examined the perceived duration not only of the second interval (t2), but also of the first interval (tl). The empty time intervals tl and t2, making a total duration of 90,180, 360, or 720 ms, were presented such that the time ratio between them changed systematically. The points of subjective equality of tl and t2 were established by the method of adjustment. In the patterns typically susceptible to timeshrinking, that is, in which t2 was underestimated, tl was perceived almost vertically. In the second experiment, listeners had to bisect an empty duration of 180 ms, marked by sound bursts. The bisecting sound marker was positioned closer to the initial marker than to the final one. Thus, tl had to be shorter than t2 in order for a regular pattern to be perceived. In the third experiment, just-noticeable forward and backward displacements of the middle sound marker were measured by a transformed updown method. The prediction that the interval of uncertainty was closer to the initial than to the final sound marker was confirmed. The three experiments demonstrated the existence of unilateral temporal assimilation, and it is argued that this perceptual mechanism causes a category of 1:1 rhythms, despite a considerable change in temporal ratio between two contiguous time intervals.

Phase transitions in [NH(CH3)3]2MeCl4(Me = Cd,Zn,Cu) crystals

Abstract Dielectric properties of the new [NH(CH3)3]2ZnCl4 and [NH(CH3)3]2CdCl4 crystals from the [(CH3) n NH4-n ]2MeCl4 group have been investigated in a wide temperature range (4.2–320 K). A series of phase transitions has been discovered at T3 = 325 K,T4 = 251 K,T5 = 193 K, for [NH(CH3)3]2CdCl4 and at T3 = 309 K, T4 = 282 K, T5 = 269 K for [NH(CH3)3]2ZnCl4. A ferroelectric phase has been discovered in the temperature interval T4—T5 from the temperature and frequency dependence of the dielectric permittivity e(T, v). According to optical investigations the existence of ferroelastic phases in the temperature interval T1 = 349 K–T2 = 391 K and below T5 for [NH(CH3)3]2CdCl4 and both above T3 and below T5 for [NH(CH3)3]2ZnCl4 has been ascertained.

Electrical transport in light rare-earth molybdates

This paper reports electrical transport studies of rare-earth vanadates (RVO4 with R = Ce, Pr, Nd, Sm, Eu and Gd), prepared by solid state reaction and characterized by X-ray diffraction studies. TGA study (300 to 1200 K) shows no weight loss; possible phase transitions in the range 1075 to 1300 K have been indicated by DTA studies. All these vanadates are typical semiconducting compounds with room temperature electrical conductivity (σ) lying between 10−4 and 10−2Ω−1m−1. Measurements of σ and the Seebeck coefficient (S) are reported in the temperature interval 400 to 1200 K. Two linear regions 400 to T1K and T1 to T2K have been obtained from the log σ against T−1 as well as the S against T−1 plots followed by a peak around T3 and minima around T4K. T4>T3>T2>T1, are different for different vanadates. It has been concluded that in the interval 400 to T1K, conduction is of the extrinsic hopping type with Ce4+ in CeVO4, Pr4+ in PrVO4 and V4+ in Nd to Gd vanadates as dominant defect centres. In the temperature interval T1, to T2K, the conduction has been shown to be of the intrinsic band type in all vanadates with polarons of intermediate coupling strength as the dominant charge carriers. Above T2 all vanadates tend to become metallic, but before this is achieved the phase change makes the conductivity smaller. T4 is close enough to the temperature corresponding to the DTA peak to be termed the phase transition temperature.

Dynamical percolation model of oil displacement by water in the oil reservoir

A quasi-quantum-mechanical percolation model, which imitates the process of oil displacement by water from the oil reservoir, is suggested. The Hamiltonian describing the irreversible evolution process of the percolation lattice, which models the oil reservoir, is constructed. With the help of the computer calculations for the rectangular plane lattice, the time development of the process under consideration is observed. The authors consider the critical behaviour within the time interval t1<or=t<or=t2 where time moment t1 corresponds to the percolation phase transition (when water appears in the production wells for the first time) and time moment t2 corresponds to the moment when the development of the percolation process is stopped (when only water begins to flow through the production wells).

Two dimensional nuclear magnetic resonance relaxation spectroscopy of molecular solids

Molecular motions in solids cover a broad dynamic range, extending from the fast rotational to the ultraslow motional regime. Two dimensional (2D) NMR relaxation spectroscopy is designed to follow these motions and to differentiate the various motional modes. The method employs the pronounced anisotropy of the nuclear spin relaxation times, observed for polycrystalline or multidomain samples. Generally, 2D NMR relaxation spectra are obtained by recording the time signals S(t2) after the last pulse as a function of successive incremented time intervals t1, corresponding to the relaxation period of the particular sequence. A Fourier transformation in both time domains transforms S(t1,t2) into a 2D representation S(ω1,ω2) of the relevant relaxation experiment. The normalized contour plot then displays the change of the corresponding relaxation rate 1/Ti along the frequency spectrum. It turns out that this variation is very dependent upon the character of the molecular motion. Model calculations for deuterons, involved in planar motions, demonstrate the potential of 2D NMR relaxation techniques. Generally, the type of motion can reliably be deduced from the shape of the contour plots. A model independent analysis provides the geometrical parameters of the dynamic process, including the jump angle ΔψK and the orientation ϑK of the rotation axis in the magnetic frame. In addition, from the separation of the contour lines the motional correlation times can be determined. The techniques are employed in the dynamical characterization of L-alanine, specifically deuteriated at the methyl group. From an analysis of 2D quadrupole echo spectra geometrical parameters of ΔψK=(120±1)° and ϑK=(70.5±1)° have been determined. Apparently, methyl group reorientation in L-alanine occurs via three-site jumps about a rotation axis, tilted by an angle of ϑK=70.5° relative to the C–2H bond direction. Computer simulations of 2D quadrupole echo and inversion recovery experiments provide the correlation times for this motion. The values range from τJ=5×10−10 s at T=353 K to τJ=3×10−5 s at T=140 K. An Arrhenius plot for these correlation times is linear over the entire dynamic range. From the slope of the straight line an activation of Ea=20 kJ/mol has been determined.

4-Hydroxycoumarin Oral Anticoagulants : Pharmacokinetics-Response Relationship

The blood coagulating factors II and VII and prothrombin times (Thrombotest) were followed during a dosage interval (= 24 h) in patients on acenocoumarol (n = 6) and on phenprocoumon (n = 6) therapy. The patients were on stable anticoagulation (%TT: 7-13%) for at least 6 months. The study was performed to investigate the concentration-response relationship of the 4-hydroxycoumarin-type oral anticoagulants. The three parameters were stable during the 24-h interval for patients on phenprocoumon therapy. Patients on acenoumarol showed fluctuations in their factor VII levels; peak activities were observed at about 2 h, trough activities at about 16 h after acenocoumarol intake. Factor II and Thrombotest activities were stable. Plasma levels of phenprocoumon were stable during daytime whereas acenocoumarol levels declined exponentially (t1/2 about 12 h). The results indicate the oral anticoagulants to exhibit a concentration-response relationship common to drug-receptor interactions. The results also suggest that for stable and long-lasting anticoagulant therapy oral anticoagulants with half-lives beyond the dosage interval (t1/2 greater than 24 h) should be preferred.

Extending the linear range for kinetic reactions by considering the relationship between enzyme activity of the reagent and measurement intervals.

We show that the rate-concentration curve is sigmoidal for enzyme-catalyzed procedures that are commonly applied to rapid automated analyzers. Linear data can be obtained by judicious selection of the reagent enzyme activity (Vm) and the measurement interval (t1 to t2). For determination of substrate concentrations much less than Km, conditions that balance linearity with sensitivity and accuracy are obtained when Vm/Km = [ln (t2/t1)]/(t2-t1). We also present theoretical and experimental data that show the linear range can be extended to concentrations exceeding the Km value. We illustrate the application of theoretically appropriate conditions by analysis of procedures reported to be optimized. Familiarity with these concepts can obviate laborious and potentially misleading experimentation.

Relapse after rigid fixation of mandibular advancement

In 19 subjects rigid fixation of bilateral sagittal split osteotomies was used for mandibular advancement. Five angles and four linear measurements were determined cephalometrically for two time intervals: before surgery to immediately after surgery (T1-T2), and immediately after surgery to six months to one year after surgery (T2-TL). A multiple regression analysis with a backward stepping procedure was used to determine relationships between relapse, as defined by the position of pogonion at T2-TL (PgT2) and B point during this same time interval (BT2). The only significant predictor of PgT2 was PgT1 (P less than 0.001) (amount of advancement of pogonion during the time interval T1-T2). When BT2 was examined, both the change in position of B point at T1-T2 (P less than 0.001) and the change in anterior facial height at T1-T2 (P less than 0.02) were significant predictors of relapse. There were no other predictors of relapse. Advancements of 6 to 7 mm or greater as measured at B or Pg deserve special attention as they were more predisposed to relapse. Methods for preventing relapse are discussed.

自然環境用ラドン娘核種モニター

We performed an attempt for application of a radon daughter monitor which enabled the measurements of individual activity concentrations of short lived radon daughters in a natural environment. The monitor was fundamentally based on a filter method with gross counting, which was refered to as Tsivoglou-Thomas method; the radon daughters in the air were sampled on a membrane filter and α rays from RaA and RaC' in the collected daughters were counted over three time intervals. By comparing these counting values with theoretical decay characteristics, the activity concentration of each of three nuclides (RaA, RaB, RaC) was obtained.The precision of the assessment of activity concentration in this method depends on several parameters related to the measuring conditions. Therefore, to enable the most precise assessment of the activity, the values of these parameters were determined, based on the calculation of error propagation. The calculation showed that the most sensitive parameters to the assessment were a flow rate (L) of sampling air, a total counting time interval (t1+t2+t3) and a waiting time (t0) which is a time interval from the end of the sampling period to the start of count. Based on the results, we determined the values of these parameters as follows: sampling time=10min, t0=10sec, first counting time interval=4min, and second and third counting interval=27min.In order to confirm the validity of the monitor, the preliminary measurements were carried out indoor and outdoor. The result offered the possibility of using the monitor to automatically assess the activity concentration of short lived radon daughters.

Stochastic monotonicity of birth–death processes

A birth–death process {x(t):t≥ 0} with state space the set of non-negative integers is said to be stochastically increasing (decreasing) on the interval (t1,t2) if Pr {x(t) &gt;i} is increasing (decreasing) withton (t1,t2) for alli= 0, 1, 2, ···. We study the problem of finding a necessary and sufficient condition for a birth–death process with general initial state probabilities to be stochastically monotone on an interval. Concrete results are obtained when the initial distribution vector of the process is a unit vector. Fundamental in the analysis, and of independent interest, is the concept of dual birth–death processes.

Stochastic monotonicity of birth–death processes

A birth–death process {x(t): t ≥ 0} with state space the set of non-negative integers is said to be stochastically increasing (decreasing) on the interval (t 1, t 2) if Pr {x(t) &amp;gt; i} is increasing (decreasing) with t on (t 1, t 2) for all i = 0, 1, 2, ···. We study the problem of finding a necessary and sufficient condition for a birth–death process with general initial state probabilities to be stochastically monotone on an interval. Concrete results are obtained when the initial distribution vector of the process is a unit vector. Fundamental in the analysis, and of independent interest, is the concept of dual birth–death processes.

On comparing two poisson intensity functions

Given realizations of two possion processes with unknown intensities A(·) and F(·) observed over the interval (t1,t2), we suppose that it is desired to distinution between H0 Ξ(·)/λ(·) is constant on (t1,t2) versus H+:Ξ(·)/λ(·) increases on (t1,t2). We propose a decision rule which uses the percentage points of the Mann-Whitney U-distribution. We show that the decision rule is unbiased and that the set of alternatives in H+ can be weakly ordered, specifically: if Ξ(·)/λ(·), β(·)/λ(·) and Ξ(·)/β(·) are increasing on (t1, t2) then P{H0 is rejected |Ξ(·)}≧P{H0 is rejected|B(·)}≧P{H0 is rejected|H0}.

Sur l'existence d'une longueur élémentaire et d'un intervalle de temps élémentaire. II

Giving a value for the elementary time interval t0 is the main purpose of this paper. For this, an analysis of the formula for the energy of a free particle is given, formula which has been found in our first paper on that subject. The value 4.4 × 10−24 s for t0 is in complete agreement with the results of our analysis. An energy band between 75 and 100 MeV is predicted as to be inaccessible for all particles at rest. The solution of the tunnel effect is given in the framework of our theory.

The effect of initial acceleration on the waves produced by a moving oscillatory surface pressure

This paper studies the effect of variation of velocity of the oscillatory surface pressure distribution over a finite time interval t0 on the wave generated from rest. The result of such an acceleration is found to produce the same steady state wave system as it would be if the pressure started impulsively with the uniform velocity at t=t0. The effect of initial acceleration is felt in the transient part of the wave system.

Sur l'existence d'une longueur élémentaire et d'un intervalle de temps élémentaire

We have briefly examined several studies which have been made concerning the introduction of an elementary length l0 and an elementary time interval t0 into physical theories. We have discussed the arguments which we have found, arguments formulated by other authors, and which support the hypotheses concerning the existence of l0 and of t0. A finite difference equation is proposed and the solutions of some problems of movement in one dimension are given.

Erneuerungsprozesse mit Wartungsstrategien

The following renewal process is considrred: given intervals (kt1,(k+1)t1],k=0, 1, 2, ..., 0<t1<∞, there will be with probabilityp, 0≤p≤1, a renewal in each interval at a time selected by random. The costs for each of this renewals are a units, while the costs of the other renewals areb units each. The renewal function and the cost function are derivided and their asymptotic behavior is discussed.

Upper bound on total cross sections

It is shown, under certain assumptions, that if the Nth derivative of the absorptive part of an elastic scattering amplitude exists in the interval t1≤t≤0, then, the total cross section has the asymptotic upper bound \({}_{\sigma T}(S) < s^{1/(N + 1)} \)

TEN YEAR EXPERIENCE WITH FURTHER ATTENUATED RUBEOLA VACCINES IN INFANTS AND CHILDREN

From July 27, 1965 to September 3, 1975, 1030 infants enrolled in the growth and development clinics at LAC/USC MC were inoculated with live further-attenuated rubeola vaccine singly, simultaneously or in combination with other live virus vaccines. Ages at the time of inoculation ranged from 167 days to 4½ years. The hemagglutination-inhibition (HAI) antibody responses of rubeola-susceptible (HAI <1:8) infants to rubeola vaccine was independent of other administered antigens. Seroconversion rates by age after 167 days at 23 day intervals (t½ human gamma globulin) were evaluated. After 335 days of age 90 to 96.6% of the inoculated infants developed HAI titers ≥ 1:8. Seroconversion rate to rubeola antigen in infants inoculated at 335-358 days of age was 91.4%; at 359-382 days, 92.6%; at 383-406 days, 96.6%; at 407-430 days, 94.6%; at 431-454 days, 93.3%; at 455-478 days, 90.9%; at 479-502 days, 92.3%; at 503-525 days, 90.0%; and at ≥ 530 days, 90.9%. The seroconversion rate in children ≥ 15 months of age was similar to that seen in infants 12-14 months of age. Our findings also suggest factors other than age which may be important in the occurrence of rubeola vaccine failures.

Dipole electromagnetic radiation in a Schwarzschild space: The wavetail to order m/r

The author considers Maxwell's equations in a Schwarzschild space and determine the retarded solutions to order m2/r2 of an electric dipole located at the centre of symmetry. The dipole moment p(t) is assumed to be variable in the interval t1 t2) to order m/r are discussed in some detail.