• Structural Engineering and Mechanics
• /
• 제57권2호
• /
• pp.201-220
• /
• 2016

A general model of equations of the two-temperature theory of generalized thermoelasticity is applied to study the wave propagation in a fiber-reinforced magneto-thermoelastic medium in the context of the three-phase-lag model and Green-Naghdi theory without energy dissipation. The material is a homogeneous isotropic elastic half-space. The exact expression of the displacement components, force stresses, thermodynamic temperature and conductive temperature is obtained by using normal mode analysis. The variations of the considered variables with the horizontal distance are illustrated graphically. Comparisons are made with the results of the two theories in the absence and presence of a magnetic field as well as a two-temperature parameter. A comparison is also made between the results of the two theories in the absence and presence of reinforcement.

• Steel and Composite Structures
• /
• 제39권2호
• /
• pp.125-134
• /
• 2021

The three-phase-lag model, thermoelasticity without energy dissipation (G-N II) theory and thermoelasticity with energy dissipation (G-N III) theory are applied to study the effect of rotation on a fiber-reinforced thermoelastic medium. The exact expressions for the physical quantities were obtained by using the normal mode analysis. The numerical results for the field quantities are given in the physical domain and illustrated graphically in the absence and presence of rotation, Coriolis acceleration as well as reinforcement parameters.

• Coupled systems mechanics
• /
• 제10권2호
• /
• pp.103-121
• /
• 2021

The present research deals with the investigation of the effect of hall current in an orthotropic magneto-thermoelastic medium with two temperature in the context of multi-phase-lag heat transfer due to thermomechanical sources. The bounding surface is subjected to linearly distributed and concentrated loads(mechanical and thermal source).Laplace and Fourier transform techniques are used to solve the problem. The expressions for displacement components,stress components and conductive temperature are derived in transformed domain and furtherin physical domain with the help of numerical inversion techniques. The effect ofrotation and hall parameter hasshown with the help of graphs.

• Geomechanics and Engineering
• /
• 제37권3호
• /
• pp.243-251
• /
• 2024

In the current work, a poro-thermoelastic half-space issue with temperature-dependent characteristics and an inclined load is examined in the framework of the three-phase-lag model (3PHL) while taking into account the effects of magnetic and gravity fields. The resulting coupled governing equations are non-dimensional and are solved by normal mode analysis. To investigate the impacts of the gravitational field, magnetic field, inclined load, and an empirical material constant, numerical findings are graphically displayed. MATLAB software is used for numerical calculations. Graphs are used to visualize and analyze the computational findings. It is found that the physical quantities are affected by the magnetic field, gravity field, the nonlocal parameter, the inclined load, and the empirical material constant.

• KSBB Journal
• /
• 제11권5호
• /
• pp.543-549
• /
• 1996

고농도 카드뮴이 함유된 배지에셔 금속 결합 단백 질인 metallothioneion 유전자로 형질전환된 재조합 S. cerevtswe BZ-pJ의 생육과 카드뮴 흡착에 미치는 영향을 살펴보았다. 카드뮴 농도가 높아짐에 따라 재조합 효모의 lag phase가 비례적으로 길어졌으며 성장은 전반적으로 느려졌고 건조균체농도도 감소하는 경향을 보였다. 카드융 220 mg/L인 배지에서 카드뮴 제거 효율이 58.6%로서 최고치를 보였다. 카드뮴 배지에 구리가 10 mg/L의 구리가 첨가 될 경우 첨가되지 않은 경우보다 재조합 효모의 spe cific cadmium uptake는 더 높아졌고, lag phase 가 2 내지 4일 정도 더 짧아졌다. 10 mg/L의 구리가 첨가된 카드뮴 630 mg/L 배지에서 자란 재조합 효모는 52.6 mg $Cd^{2+}$/g dry cell을 축적하였다. 카드뮴 680 mg/L 배지에 구리의 첨가량이 11에서 33 mg/L로 증가됨 에 따라 specific cadmium up­t take가 17.0에서 42.0 mg $Cd^{2+}$/L dry cell로 증가하였다. 건조균체농도, specific cadmium uptake rate, 카드뮴 제거 효율 등이 전반적으로 향상되였다. 카드융 100 mg/L에서 척응한 재조합 효모가 본배양 배지로 옮겨질 때 최단기간의 lag phase를 보였지만 가장 낮은 비성장속도를 나타내였다.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제51권7호
• /
• pp.387-398
• /
• 2002

In this paper, a new Three-Phase Lead-Lag Random Pulse Position PWM(LL-RPWM) scheme is proposed and implemented for decreasing audible acoustic noise of motor drives. In the proposed RPWM(Random PWM), each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the randomization of the PWM pulses, we can obtain the effects of spread spectra of voltage, current as in the case of randomly changed switching frequency. To verify the validity of the proposed LL-RPWM, the simulation and experimental study was tried. Along with the randomization PWM pulses, the space vector modulation is also executed in the C167 micro-controller. The simulation and experimental results show that the voltage and current harmonics are spread to a wide band area and that the audible acoustic noise is reduced by the proposed RPWM method.

• 대한기계학회논문집A
• /
• 제25권11호
• /
• pp.1759-1766
• /
• 2001

Vibration transient generated by developing localized fault in gear can be used as indicators in gear fault detection. In this paper, we propose the zoomed phase map for a fault signal using continuous wavelet transfers to detect this vibration transient. Local fault induces the abrupt fluctuation of load exciting tooth and phase lag in the vibration signal measured on the gearbox. The relatively large fault like "tip breakage" easily can be detected by the clear fluctuation of exciting load. However, minor fault like "initial pitting"cannot be detected using the load fluctuation. To defect this kind of minor fault, the phase map for a fault signal is taken into account. The phase lag by minor fault is observed well in the zoomed phase map.

• Clinical and Experimental Reproductive Medicine
• /
• 제13권2호
• /
• pp.113-119
• /
• 1986

The present study was designed to assess the relationships between the methods to evaluate adequacy of luteal function. We measured mid-luteal serum progesterone levels by radioimmune assay, luteal phase lengths and mean post-ovulatory basal body temperature rise rates by basal body temperature charts in 40 in-phase-cycle infertile patients and 38 out-of-phase-cycle patients who underwent late-luteal endometrial biopsies at the sterility clinic of Department of Obstetrics and Gynecology, Seoul National University Hospital from Jan. 1986 to Aug. 1986. The results were summarized as follows: 1. No significant differences were found in mean age, mean duration of infertility, mean mid-luteal serum progesterone levels, and mean post-ovulatory temperature rise rate between in-phase-cycle patients and out-of-phase-cycle patients, but significant difference in mean luteal phase length between 2 groups was identified. 2. 91% of total patients sho had luteal phase lengths of less than 11 days showed out-of-phase-cycles. 3. In out-of-phase-cycle group with luteal phase lengths of less than 11 days, 50% had an endometrial lag of at least 4 days, but 10.7% had an endometrial lag of 4 or more days in group with luteal phase lengths of more than 11 days. 4. There was no significant correlation between mid-luteal serum progesterone level and endometrial lag of late luteal phase endometrial biopsy.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2001년도 춘계학술대회논문집
• /
• pp.590-595
• /
• 2001

Vibration transient generated by developing localized fault in gear can be used as indicators of condition monitoring in a gear. In this paper, we propose the phase map for a fault signal using continuous wavelet transform to detect this vibration transient. Local fault induces the abrupt fluctuation of load exciting tooth and phase lag in the vibration signal measured on the gearbox. The relatively large fault like "tip breakage" easily can be detected by the clear fluctuation of exciting load. However, minor fault like "initial pitting" cannot be detected using the load fluctuation. To detect this kind of minor fault, the phase map for a fault signal is taken into account. The phase lag by minor fault is observed well in the phase map.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
• /
• pp.998-1001
• /
• 1988

A robust control method for robots in presented. In this method, a phase-lag controller is used for reducing the effect of the unknown payload without the measurement of joint accelerations and torque/force. Simulation results for the lower 3 joints of PUMA 560 show considerable reduction of position errors due to the unknown payload, compared to the computed-torque method.