International Journal of Advances in Engineering Sciences
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159 research outputs found
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Transient Stability Analysis of Electrical Power Systems by means of LabVIEW based Simulation of STATCOM
No full textTransient stability is the capability of the power system to maintain synchronism under the condition of a severe and fast disturbance in the system. Flexible AC Transmission System (FACTS) devices are used to control power flow along transmission lines and improve power system stability. Static Synchronous Compensator (STATCOM) is one of the second generation FACTS devices that are usually used for voltage regulation. It so also used to improve power system stability by injecting or absorbing reactive power. In the present work the authors have made an attempt to simulate STATCOM in terms of transfer function models. These simulated models have been tested by incorporating them in a simple single-machine infinite-bus (SMIB) system as well as in a multi-machine power system. LabVIEW software has been employed for the simulation purpose. LabVIEW is a new research tool which is capable of representing dynamic systems in block diagram form, along with the provision of simulation of the system behavior in totality. This simulation technique also reduces the system complexity from a developers standpoint, and thus allows the researchers to concentrate on the application details. Such facilities are not available in the traditional means of measurement techniques and tools. Simulation results are encouraging and indicate that the proposed simulation model is very close to the physical simulation
DRUG METABOLISM
No full textThe termmetabolism, derived from the Greek language, simply means change or transformation. It relates to various processes within the body that convert food and other substances into energy and other metabolic byproducts used by the body. Drug metabolism is the bodys way of transforming drugs, so they can be excreted from the body. Many drugs arenot active until they have been metabolized in the body by enzymes that transform them. Most drugs are lipophilic, meaning they pass through membranes to reach their target site. Most drugs are treated by the body like foreign substances, also known as xenobiotics. Humans have evolved a complex system for xenobiotic metabolism
Inhibitive Effect of Organic Inhibitors in Concrete Containing Quarry Dust as Fine Aggregate
No full textConcrete is the widely used building material in the world. River sand has been the most popular choice for the fine aggregate in concrete in the past, but overuse of the material has led to environmental concerns, reduction of sources and an increase in price. Quarry dust has been proposed as an alternative to river sand that gives additional benefit to concrete. The objective of this work is to study the strength and corrosion resistive properties of concrete containing quarry dust as fine aggregate along with organic inhibitors namely Triethanolamine and Diethanolamine at 1%, 2%, 3% and 4% by weight of cement. The specimens were tested for compressive strength, split tensile strength, flexural strength, and bond strength in addition to water absorption. The resistance to corrosion is evaluated based on the performance of the concrete for the penetration of chloride ions by means of Polarization Technique, Rapid Chloride Penetration Test (RCPT) and Gravimetric weight loss method. From the results obtained, it is found that replacement of sand by well graded quarry dust along with super plasticizer increases the strength of concrete; with the addition of inhibitors it offers very good resistance against chemical attack and increases corrosion resistance in addition to overall properties of concrete. The optimum percentage addition of the organic inhibitors by weight of cement in concrete containing quarry dust as fine aggregate was also determined
Elimination of Resonant Internal Harmonics in Power Electronic Converters
No full textPresent electrical power system is polluted bycomplex harmonics generated by power electronic converters.Even though external harmonics are reduced by advancedfiltering techniques, still resonant internal harmonics createcritical behavior of power system. Resonant internal harmonics(RIH) are not identified by the present harmonic reductionmodels. A model is proposed to identify and eliminate resonantinternal harmonics produced by power electronic converters. Theproposed model has been tested through simulation on single andthree phase thyristor valve converters and the results thusobtained are pres
RESEARCH CHALLENGES AND MATERIAL FOR FUTURISTIC CMOS DEVICES
No full textNow a days Engineers are involved withproblems ahead below 100nm gate length MOStransistor technology. The downsizing of the MOSdevices results to smaller area, smaller powerconsumption and improvements in performance ofdevice and circuits. The further scaling down ofComplementary Metal Oxide Semiconductor (CMOS)transistors requires replacement of conventional silicondioxide layer with higher dielectric constant (K)material for gate dielectric. In order to reduce the gateleakage current, and also to maximize gate capacitance,high K gate oxide materials such as Al2O3, ZrO2, HfO2,Ta2O5, TiO2, Gd2O3, are under investigation. In thispaper titanium dioxide (TiO2) is chosen as an alternateto silicon dioxide (SiO2).Here thin film of TiO2has beengrown practically and characterized. The samplesdeposited by sol gel spin coating method werecharacterized using X-Ray Diffractometer and thicknesswas measured using Scanning Electron Microscope(SEM). The grain size was found to be several tens ofnanometer
Fatigue Failure Analysis of Hollow Cylindrical Roller Bearing
No full textCylindrical roller bearings with hollow rollers are advantageous in applications where weight, lubrication and speed are major considerations in the operations of the bearings. An improvement in load distribution and thus load capacity may be realized, as well as contact stress is also reduced considerably by using a bearing with hollow rollers. Since from the implementation, for hollow roller bearing no method is available for the calculation of hollowness and contact stresses and ultimately premature failure will occur without performing its optimum life. In the present work failure analysis of Hollow Cylindrical Roller Bearing (HCRB) made from AISI 52100 is carried out to understand the type and mode of failure. This bearing is basically used in earthmoving equipments where heavy load is applied on bearing. The objective of the work is to identify the type of failure by using material oriented investigations. It was found that flexural fatigue is the mode of failure occurs in this bearing the reason for which is wrong selection of hollowness
VLSI DESIGN OF LOW POWER HIGH SPEED ADC
No full textAnalog-to-digital converters (ADCs) are key design blocks in modern microelectronic digital communication systems. With the fast advancement of CMOS fabrication technology, more and more signal-processing functions are implemented in the digital domain for a lower cost, lower power consumption, higher yield, and higher re-configurability. This has recently generated a great demand for low-power, low-voltage ADCs that can be realized in a mainstream deep-submicron CMOS technology. Various examples of ADC applications can be found in data acquisition systems, measurement systems and digital communication systems also imaging, instrumentation systems. Hence, we have to considered all the parameters and improving the associated performance may significantly reduce the industrial cost of an ADC manufacturing process and improved the resolution and design specially power consumption . In this paper we have proposed a design of ADC, in 0.18um CMOS process
Design of Low Power VCO using >2G Hz Technology
No full textThe design challenges are increasing with the increase in demand for low power, high-frequency wireless systems. The reasons are poor phase noise performance of integrated VCO and large area taken by the loop filter. Many recent reporting show that with careful design, on-chip VCO can be made to give comparable phase noise performance with off-chip VCO. In this paper we have presented a design of a ring oscillator which is implemented in CMOS