NTU Journal of Engineering and Technology

The waste heat energy discharged into the atmosphere by a car engine's fuel consumption provides more than 70% of the energy. We can use waste heat energy in a car's exhaust system if a thermoelectric generator is used to convert the lost thermal energy into electricity. A thermoelectric generator is a device that uses the Seebeck effect to turn temperature differences into electricity. A thermoelectric generator is a device that uses the Seebeck effect to transform temperature differences into electrical energy. In this study we examined the feasibility of installing thermoelectric generation in cars exhaust system and test it's ability to use the thermal waste energy to produce electrical power. As a result, Changes in speed, vehicle load, and surrounding environmental variables affect the thermoelectric generators performance to product electrical usuful power also We predict that at 20°C, the output power for each thermoelectric generator device is 1.18 watts in the best environmental conditions.

Principle analysis results provideconstruction new digital-analog jammers from the point of view minimizingout-of-band undesirable electromagnetic radiation.Reviewed methods of compensating for nonlinear distortions, which are suitable for use in power amplifiers of jammers, based on linearization methods of the characteristics of powerful amplifying devices. The substantiation of a new compensation method foreliminating undesirable combination components in the spectrum of jamming transmitters with quadrature modulation (the method of depletion of the input signal spectrum).

This study utilized Nano fluid as a cold fluid in evaluating the counter flow double tube heat exchanger, which will one meter long, an outer diameter of 19 mm, and an inner diameter of 9.5 mm made of copper. Water was the basic fluid, mixed with 40 nm, a volume concentration of (0.5%) and (1%), respectively, of CuO nanoparticles. At 2 L/min , 4 L/min and 6 L/min, Nano fluid flows inside the inner tube. At 20°C, the Nano fluid enters the heat exchanger. The flow of hot water into the heat exchanger is 4 L/min throughan annular space with an entry temperature of 65 °C. To achieve better heat exchanger performance. The experimental results will compare to those of pure water. The improvement in performance with Nano fluid as a working fluid was found as (40%) maximum effectiveness obtained at Nano fluid flow rate of 2 L/min with (0.5%) volume concentration and effectiveness (54%) at (1%) a volume concentration.

The voltage sag condition in the power system has a direct effect on the quality of the power system. Voltage sag has a major effect on sensitive-voltage loadscausing a high inrush current, failure in the system, and price loss.The Dynamic Voltage Restorer(DVR) is regarded as one of the effective methods tocontrol voltage in a power system. This paper describes the DVR control unit based on PQ theory to enhance the quality of the power system. The suggested control technique utilizes 3-phase compensation modules, based on the desired Sag condition. Also, this paper used LabView software to simulate the DVR for voltage variation in a power system.

The present study aims to evaluate and analyze the gas turbine power generation unit (K3) in Kirkuk gas power station under actual weather conditions of (2017), which is located south of Kirkuk in Taza district. (K3) unit capacityproduction estimated at (255 MW) at maximum load The unit consists of a gas turbine and an air compressor connected to the generator via a common shaft and operates in the Joule-Brighton simple cycle. The current study dealt with the analysis of the energy and exergy for the mentioned unit based on the law of conservation of mass, the first law, the second law in terms of the influence of each of the factors (ambient temperature, compression ratio, and relative humidity). Two methods were used to simulate the working data; the first is simulation programming by Excel, and the other is by using CHEMCAD software. The average data have been used in the simulation process for each month in that year to evaluate the performance of the unit K3.The simulation results showed that the combustion chamber represents the most important part in the exergy destruction, the largest energy rate can be obtained from fuel as chemical, and the results of both methods showed maximum energy where energy efficiency was around (37.67%) and (36.89%), respectively

With many applications using digital multimedia technologies, the need to protect digital multimedia data from hackers is emphasized. Copyright holders are concerned about protecting any kind of unlawful duplication of their information. With all these kinds of problems, technology development is very important. Digital watermarks are an important requirement to protect multimedia data. There are important criteria to measure the success of a watermarking process, itsconfidentiality, capacity and reliability. In this paper, the logo mark was relied upon to achieve these criteria by taking advantage of the symmetry characteristic of the logo image, which is often used this type of logo images. Symmetry reduces the size of the embedded data, reduces the location of the embedded within the image, and increases confidentiality by encrypting less data in various ways.

This experimental work dedicated to find the thermal performance of triangular fins in two cases, non-perforated and perforated showing the effect of input factors on the thermal performance. Experiments were carried out by testing threefins for the above two cases and the value of heat input rate with three values: 25.69, 63.58, and136.9 W. many fixed thermocouples were uesed to measure the temperature in the root of the fin and points along its extension and an additional point to measure the ambient temperature. The Rayleigh number and the Nusselt number were calculated. Theeffect of the Rayleigh number on the Nusselt number was shown. The results showed that the total heat transfer coefficient of the air increases with the increase in heat added in both cases. In addition, it was found that the temperature decrease along the perforated fin is greater than that of the non-perforated fin, and the total Nusselt number increases with the increase in the heat rate input for both cases. The thermal resistance decreases with the increase in Rayleigh number, both perforated and non-perforated. It was also concluded that the non-perforated fins were more efficient in dissipating heat than the perforated fins, and the reason for this is that the heat transfer was under free convection conditions.