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Farmakopeya — dori vositalari sifatini, ularni tayyorlash, sifat miqdori jihatdan nazorat qilish, saqlash shart-sharoitlari va nomlanishini belgilaydigan davlat standartlar to‘plami.

Microelectromechanical System (MEMS) Sensor technology has revolutionized the electronics industry with its wide array of applications from wearable electronics to precision instrument for biomedical applications. However, two of the most inherent problems with these sensors are low capacitance-to-voltage conversion of sensors and its high susceptibility to noise. Since MEMS sensors have been developed over the years, and as to meet the surging market demands of interface circuits, the need for upgrading its features has led to the integration of more complex designs This paper presents an integrated approach for MEMS switched capacitor-based interface which is implemented using a Low Noise Operational Transconductance Amplifier (OTA) design and a digital clock control block implemented in 65nm CMOS Process. The OTA design composes of a noise buffer preamplifier cascaded to a conventional folded cascode amplifier topology. The OTA design obtained parameters values with an open loop gain of 65.5 dB, Unity gain bandwidth of 8.48 MHz, PSRR+ of 65.2 dB and PSRR-of 93.3 dB and a CMRR of 115 dB. Input referred Noise is at 18.369 nV/√Hz. MEMS sensors signal are initialized at the input as MEMS sensors are beyond the scope of this study. With a MEMS noise model, the obtained noise cancellation ability of the proposed amplification and noise cancellation network is known to be 88.765%. The overall circuit covers a chip area of $242\ \mathbf{um}\times 705\ \mathbf{um}$

This research paper presented a design that will address the challenges brought by remanence in ground-fault current interrupter devices (gfci). Remanence or residual magnetism is the magnetization left behind in a ferromagnetic material (such as iron) after an external magnetic field is removed. Remanence will make the gfci devices less accurate and less reliable in tripping the current above threshold in just five (5) years. It affects the performance of the device in terms of efficiency, accuracy, and response time. In this research, the problems caused by remanence were alleviated by using two identical transformers in detecting residual current both for hot and neutral wires. The difference of the current detected by the two transformers will be the basis of the signal threshold in tripping the device. By doing so, the problems caused by remanence phenomenon will be solved without compromising the response time of the circuit which is around 16 mS. The design will extend the life span of GFCI devices up to 15 years.

This study focuses on the design and implementation of a variable duty cycle pulse train charging (VDCPTC) strategy aimed mainly to reduce the detrimental effects of sulfation in order prolong battery life. This paper proposes a pulse train type of charging unique from that of conventional pulse charging. A burst of pulses at 1 kHz frequency is injected in the battery via a 345W/57.6V Half Bridge LLC resonant converter. The pulse train charger was designed and implemented with a microcontroller that controls a switch turning on and off producing the charge pulses to the battery. The experiment is done through 3 sets of partially sulfated batteries subjected to charge and discharge cycles. Results show improvements in the discharge performance after tests. The discharge time improvement shows that the charge carrying capability of the battery has improved under pulse train charging. The discharge performance improvement is consistent with the battery impedance findings. Internal battery impedance after pulse train charging is reduced to a third from its original value. A 10% charging time improvement is observed compared to conventional CC-CV charger.

This paper focuses on the design and implementation of a Half Bridge LLC resonant converter for Light Electric Vehicle (LEV) battery charging applications. The proposed charger is designed to have high efficiency, low component cost, wide output voltage range, and low switching losses to maximize energy transfer through the converter to the battery using Constant Current (CC) and Constant Voltage (CV) control methods. The experimental results of the LLC resonant converter prototype, fed by a 322–420V PFC output, converts universal AC input to 57.6V DC at 345W power operating at peak efficiency of 96.3%.

This paper presents the design and implementation of a hybrid controller for AC to DC power factor correction (PFC) converter. A hybrid controller for the PFC integrates the analog current and digital voltage controllers to perform the hybrid method operating in average current-mode control (ACMC) with a switching frequency of 100 kHz to achieve low harmonic distortion, low ripple output voltage and high efficiency. The digital controller is realized with an 8-bit microcontroller configured as a proportional integrator (PI) compensator to compensate the output voltage to its desired output value. It can improve output voltage regulation against line and load variations. Moreover, this converter circuit is verified through Matlab/Simulink behavioral simulation. Finally, the results show the improvement is effective using an experimental prototype rated at 10W. It gives a higher power factor closes to unity with high efficiency. The converter efficiency is higher than the required energy-efficiency imposed by Energy star. The THD is approximately 9.587% and the ripple output voltage is around 0.93%.

Transmission open access has increased the need for reactive power and voltage support in power systems with electricity markets due to the higher requirement for system security and reliability. A Reactive Power Dispatch Optimization (RPDO) method that can be used by the system operator to centralize the scheduling of reactive power from generators is proposed. By centrally scheduling the reactive power outputs of the available generators, the bus voltages in the network can be maintained within the grid code limits while satisfying line flow limits. Given the real power energy schedules that are predetermined by the electricity market, the RPDO method finds a set of generator reactive power schedules that will maintain the bus voltages within acceptable limits, and satisfy generator reactive power and power factor constraints, while minimizing ancillary service payments for reactive power support and for regulating real power. Tests using the IEEE 30-bus system show the effectiveness of the proposed method.

MAGISTER EN METEOROLOGIA Y CLIMATOLOGIA FONDECYT FONDECYT

MAGISTER EN ENSEÑANZA DE LAS CIENCIAS CON MENCION EN DIDACTICA DE LAS MATEMATICAS http://sial.fondecyt.cl/index.php/menu/principal FONDECYT FONDECYT

Current clinical therapies have limited capacity to restore function in damaged nerves. Regeneration of axons in the injured central nervous system is inhibited by the presence of both physical and mechanical barriers. As such, neural tissue engineering strategies have received considerable attention in recent years. Materials-based approaches offer a way to blend synthetic and biological components in order to generate environments conducive to neural regeneration. While biomaterials themselves can facilitate regeneration simply by providing a substrate for cell growth, incorporation of “bioactive cues”—or molecules which interact with cells to elicit a specific response—has become increasingly necessary in order to promote nerve regeneration. This review attempts to outline the various biomaterials that are promising for central nerve applications, and discusses the array of bioactive cues that are valuable in promoting nerve repair.

INTRODUCTION On January 12, 2010 an earthquake of 7.0 on the Richter scale struck Haiti, the poorest country in America. The quake’s epicenter was in Leogane with extension to almost all the country also hitting Port-au-Prince, the country’s capital. This disaster caused a huge destruction and devastated more than 250,000 of houses and commercial buildings and left more than a million of homeless people. In the aftermath, this catastrophe caused 230,000 deaths and more than 30,000 wounded people (). () [...]