One-Input Three-Output Current-Mode Universal Filter Using Translinear Current Conveyors

This paper presents a new current-mode universal filter with one-input three-output employing three translinear current conveyors and two grounded capacitors. The proposed filter provides low-pass, band-pass, high-pass current response with high output impedance output which can be directly connected for current-mode circuit. The band-pass and all-pass filters can also be obtained. The parameters wo and Q can be controlled separately and electronically by the bias currents of current conveyors. For realizing all filtering functions, no passive and active matching conditions are required. The active and passive sensitivities are low. The characteristic of the proposed circuit can be confirmed by SPICE simulations

Current-Controlled Current-Mode Quadrature Oscillator Using Translinear Current Conveyors

In this paper, a current-mode quadrature oscillator using second-generation current conveyors (CCIIs) is presented. The proposed oscillator consists of two CCIIs, two grounded capacitors and two grounded resistors. The circuit is suitable for integrated circuit implementation by using grounded capacitors. In addition, a new current-controlled current-mode quadrature oscillator using two current controlled second generation current conveyors (CCCIIs) and two grounded capacitors can be obtained by replacing CCIIs and resistors series at X terminals with CCCIIs. The condition of oscillation and frequency of oscillation can be orthogonally controlled. The frequency of oscillation can be controlled by grounded resistors and external bias currents. The proposed circuits have been simulated by SPICE simulations. The simulation results are confirmed the proposed theory

A simple current-mode Schmitt trigger employing only single MO-CTTA

Abstract- A new current-mode Schmitt trigger based on MO-CTTA (Multiple output current through transconductance amplifier) is presented in this article. The circuit description is very simple, its construction consists of only single MO-CTTA. The hysteresis and amplitude of the output current can be tuned independently/electronically. With mentioned features, it is very suitable to realize in a monolithic chip. The PSPICE simulation and experimental results are depicted, and agree well with the theoretical anticipation. The maximum power consumption is approximately 249mW at ±5V supply voltages. I

Evaluation of the Teacher Development Project for the Local Development Scholarship Program in Northern Thailand

This mixed-method study aimed to evaluate the Teacher Development Project for Local Development (TDPLD) program in northern Thailand from 2016-2020. The aspects of evaluation included outputs, outcomes, and impacts in various dimensions. Ten groups of 3,041 individuals were identified for sampling using voluntary selection, purposive sampling, and snowball sampling techniques. Qualitative research methods were used on 702 participants, while quantitative means were employed on 2,339 informants. The results revealed that before entering the TDPLD development course, individuals exhibited a high level of competency in local development. Further analysis also showed that during each participant’ s induction period (the period before employment as a teacher), they gained the necessary knowledge that could be used to create tangible learner development. Unfortunately, promises of hometown teaching assignments were sometimes not kept. A common thread throughout the study was the need for English language skills preparation and funding. The study contributes significantly to the literature because it is one of Southeast Asia’s most extensive teacher development studies ever undertaken

The influence of leg positioning on the appearance and quantification of 1H magnetic resonance muscle spectra obtained from calf muscle

Purpose: To study proton magnetic resonance spectra (1H-MRS) of the muscle metabolite of a leg muscle in neutral (NEU), internal rotation (INT), and external rotation (EXT) leg positioning. Material and methods: The volunteers were selected for this study. The tibialis anterior (TA), soleus (SOL), and gastrocnemius (GAS) muscles of a non-dominate leg were determined by using single-voxel spectroscopy 8 × 8 × 20 mm3 in size. 1H-MRS measurements were performed on a 1.5-Tesla magnetic resonance imaging (MRI) scanner. Results: The results showed that metabolite spectrum of muscle in each NEU, INT, and EXT of leg positioning were not similar. Additionally, the quantification of IMCL (CH3) and EMCL (CH3) is significantly different in SOL. Conclusions: Our study showed that leg positioning influences the appearance and quantification of 1H-MRS in the calf muscle. Hence, it is necessary to pay close attention to positioning because it interferes with spectral fitting and quantification

BIOANALYTICAL METHOD VALIDATION FOR DETERMINATION OF ROSMARINIC ACID IN SIMULATED BIOLOGICAL MEDIA USING HPLC

Objective: This study aims to develop and validate a simple, rapid and accurate HPLC method for the determination of rosmarinic acid (RA), an active marker of Thunbergia laurifolia (TL) tea, in Hank's Balanced Salt Solution (HBSS) using HPLC. Methods: The separation was performed using a Xterra® C18 reversed-phase column (150  3.9 mm, 5 µm). The mobile phase consisted of 0.5% (v/v) glacial acetic acid (A) and acetonitrile (B). The flow rate was 1 ml/min and detection was carried out at 330 nm with UV-visible spectrophotometer. The method was validated according to the US FDA guidance on bioanalytical method validation in 2018. Results: The method was successfully validated in the range of 50-500 ng/ml of RA. Intra-and inter-day precision ranged from 1.6 to 2.1% and 1.4 to 4.5%, respectively. Intra-and inter-day relative errors (% bias) were less than 7.6 and 3.6%, respectively. In addition, it was found that the stability of RA in HBSS could be dependent on the pH and temperature. Conclusion: The developed method met the validation requirements and could be further applied to the permeability study of RA using an in vitro Caco-2 cell monolayer model

วงจรทวีค่าความจุไฟฟ้าแบบลงกราวนด์โดยใช้วงจรสายพานกระแสรุ่นที่ 2

This research proposes the design and production of a grounded capacitance multiplier, that comprises of resistors and a capacitor. The results obtained depend on the gain of the circuit which is controlled by the resistors, in which the grounded capacitance multiplier that is presented produces the standard value according to theory. The results from simulation by PSpice is correlated with actual evaluation that has standard deviation of ±5

High input impedance voltage-mode universal filter and its modification as quadrature oscillator using VDDDAs

The second order universal voltage-mode filter using voltage differencing differential difference amplifiers (VDDDAs) has been proposed. It has high input impedance voltage-mode biquad filter with orthogonal tune of natural frequency and quality factor. The proposed filter simultaneously provides five filter responses: low-pass (LP), high-pass (HP), band-reject (BR), all-pass (AP) and band-pass (BP) in the same circuit topology. The natural frequency and quality factor can be tuned electronically and orthogonally dc bias current. The output impedance at output nodes HP, AP and BR has low impedance which can connect to other circuit without the use of voltage buffers. The proposed filter consists of three VDDDAs, one grounded resistor and two grounded capacitors. This makes the proposed filter suitable for integrated circuit development. With slightly modifying the proposed filter, the voltage-mode qudrature sinusoidal oscillator with low output impedance and independent control of condition of oscillation (CO) and frequency of oscillation (FO) has been achieved. The results shown in this paper are from PSPICE simulation and experiment to validate the proposed circuits