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One way to overcome the problem of air pollution caused by motorized vehicles is to add a catalytic converter to the motor vehicle gas exhaust system. Catalytic Converter is a tool used to reduce pollutant emissions from internal combustion engines. One of the transition metals that can be used as a catalyst is copper which has the ability to assist the process of reducing and oxidizing exhaust gas emission compounds. This study aims to control and reduce air pollution in order to reduce and minimize negative impacts on humans and the environment. Catalytic Converter based on copper plate with a perforated spiral shape as a tool for advanced combustion in reducing and oxidizing emissions. The spiral shape minimizes backpressure, as the air faces less resistance and slides around in the converter. This gliding motion allows for reduced back pressure. The method used is experimental, starting with the design, then making a copper catalytic converter with a perforated spiral shape. Furthermore, testing using a catalytic converter and without a catalytic converter is carried out to find out how much exhaust gas emissions are. The results showed that the copper catalytic converter in the form of a perforated spiral can reduce HC gas by 23% and CO gas by 25%. [ABSTRACT FROM AUTHOR]

The increase in the number of motorized vehicles as a common transportation has an impact on increasing air pollution. Air pollution from motorized vehicles that exceeds the threshold will result in health problems and even death in certain cases. This is because motor vehicle exhaust emissions contain harmful pollutants including carbon monoxide (CO) and hydrocarbon (HC). One of the technologies that can be used to reduce motor vehicle exhaust emissions is a catalytic converter which is installed in the exhaust duct of motorized vehicles. Catalytic converter is a tool to HC and CO emissions by using oxidation and reduction catalysts. One alternative material that can be used as a catalyst is copper (Cu). The purpose of this study was to determine the effect of using a catalytic converter with a copper (Cu) catalyst on the concentration of carbon monoxide (CO) and hydro carbon (HC) gases in the exhaust gas of a 150cc 4 stroke motorcycle. The method used is experimental, namely designing and designing a copper catalytic converter with a perforated spiral shape. Furthermore, testing and comparison of exhaust gas emission results without and using Catalytic is carried out. Based on the research results, the copper catalytic converter in the form of Swirl Blades can reduce HC gas by 41 ppm, CO by 28% and CO2 by 32%. [ABSTRACT FROM AUTHOR]

Slug is one of the flow patterns that endanger pipe construction in the industry due to significantly large pressure fluctuations. As an anticipatory step to determine the initial conditions of the slugging phenomenon, research that discusses the characteristics of slug formation is thus pivotal. The present work has been conducted on a horizontal acrylic pipe with a diameter of 16 mm, with a total length of 10 m, equipped with a correction box for visual data retrieval employing the Panthom Miro M310 high-speed camera. Data collection was gathered in the fully developed L/D 180-210 area. Liquid hold-up data was obtained by utilizing the CECM method to confirm the type of fluid flow pattern, while data processing was conducted to obtain the average value of liquid hold-up. The utilized fluids include liquid and gas under environmental conditions, with variations in the liquid superficial velocity from 0.03 to 0.3 m/s and the gas superficial velocity from 0.7 to 10 m/s. From this study, it was navigated that the slugging phenomenon emerged through 2 mechanisms. In the wave growth mechanism, an accumulation of liquid increases the film thickness. If the interfacial velocity difference is potentially large, the liquid will reach the top of the pipe forming a slug flow. This condition is supported by the average value of liquid hold-up which drastically decreases when the stratified flow pattern transitions to slug flow. In the wave coalescence mechanism, a high aerated slug is formed through stratified wavy and pseudo slug flow patterns. Hence, there is no decrease in the average value of the liquid hold-up because the flow pattern is nearly uniform. The addition of the JG value to this mechanism would thus enlarge the aeration of the liquid slug. [ABSTRACT FROM AUTHOR]

The annual growing number of motorized vehicles generates an unexpectedly depraved impact on the environment, especially on the pollution due to exhaust gases. Therefore, it is compulsory to modify the combustion gas filter system prior to being released into the environment. It is thus not surprising that the exhaust gas filter in the form of a catalytic converter has been continuously industrialized for this purpose. This research aims to discover a catalytic converter design made from a catalytic combination of brass wire and copper wire in the shape of spiderwebs by examining the catalytic converters exhaust emissions. The combined catalyst of brass wire and copper wire in the shape of a cobweb is preferred as a catalyst for catalytic converters. Regarding the affordability and accessibility, the discussed catalysts are feasible to reduce and oxidize motor vehicle emissions. The applied method in this research is the experimental method, containing steps initiated from designing the catalytic converter housing, determining the type of catalyst, to constructing a spiderwebs catalytic converter made from a combination of copper brass wire. Furthermore, testing is conducted to determine the exhaust emissions of motorized vehicles employing catalytic converters and without using catalytic converters. The results of emission testing affirmed that the application of catalytic converters made from a combined brass wire and copper wire in the shape of a spider's web could significantly reduce HC and CO emissions, along with the increasing CO2 emissions. The reduction in HC gas emissions was 39 ppm or 16.72% compared to the value without using a catalytic converter. The reduction in CO gas emission was 4.5 ppm or 20.45% compared to the value without using a catalytic converter. Meanwhile, CO2 gas emissions increased by 4.3 ppm or 9.7% compared to the value without using a catalytic converter, due to the addition of oxygen in the oxidation process. [ABSTRACT FROM AUTHOR]

Slug is one of the most avoided flows in the piping system network. The high pressure fluctuations can cause damage to the pipes. Therefore, prevention of the slug flow is very important. To understand the phenomenon, an experimental study to investigate the pattern of stratified to slug flow transition has been examined. The present work was conducted on a 26 mm diameter acrylic horizontal pipe with the length of 10 m. Air and water are used as working fluids. Visual image capture is done using Phantom Miro M310 High speed camera on L/D 180-210 from inlet. As a supporting visual observation result, CECM method is also used to measure liquid holdup of fluid flow. The onset of slugging mechanism due to change of both gas and liquid superficial velocity will be discussed. As a result, it is found that the slug formation from stratified flow is at least divided into two basic mechanisms. At low gas velocity, the slug stability condition is created by wave growth mechanism. The increase of JG resulted in the increase of aeration and the of the liquid slug length. When the gas velocity is above 3 m/s, wave coalescence and large disturbance waves initiated the onset of slugging. The Increase of JL on the high JG makes the roll waves higher to create a pseudo slug. In addition, it is found that the formation of high aeration slug is seen at JL = 0.3 m/s when JG is maintained at 3.77 m/s. [ABSTRACT FROM AUTHOR]