Motorcycle Exhaust Research Articles

Nanocatalyst manganese oxide (MnO) for exhaust emissions (CO and HC) reduction

The growing number of motor vehicles, particularly the exhaust gas as a result of incomplete combustion of fuels, has a very adverse impact on the environment. One effort to reduce exhaust emission levels is by applying a catalytic converter to the exhaust system. MnO is a chemical mixture that can be applied to a catalytic converter to reduce exhaust emissions because it is capable of binding CO and HC contained in motorcycle exhaust gases. This research was an experimental research aiming to investigate the difference in emission level of CO and HC between a motorcycle with and without a catalytic converter. The types of fuel used were RON 88 and RON 92. The results showed that the application of MnO as a catalyst could reduce the level of CO significantly in RON 88, i.e. 24.36%, and the level of HC in RON 88 and RON 92, i.e. 82.08% and 38.14 % respectively.

Implications of Lack of Maintenance of motorcycles on Ambient Air Quality

This paper reported the results of the investigation of motorcycle emissions in selected roads in Abeokuta, Nigeria. Five roads: Ijaye, Kuto, M.K.O. Abiola way, Olabisi Onabanjo, and Olorunsogo roads were considered with five different motorcycle types (Bajaj, Day Long, Frajend, Hajue Suzuki and Honda) on each road. Motorcycles were parked 8.0m away from the main road in downwind direction. The motorcycle exhaust emissions monitored were CO2, O2, CO, and HC emissions. The total mean concentration of measured CO2 emission from motorcycle exhaust on all the roads, ranged between 18800ppm for Frajend and 37400ppm for Bajaj, while O2 ranged between 139200ppm for Honda and 171800ppm for Frajend, also CO ranged between 14500ppm for Hajue Suzuki and 30700ppm for Bajaj, and HC ranged between 674ppm for Honda and 3289ppm for Day Long. It could be noted that the air pollutants are high for almost every type of the motorcycles, and significantly higher than the National standards. This implies that these motorcycles, which are mostly used for commercial purposes are poorly maintained. This study therefore concluded that motorcycle pollution in Abeokuta is significant with possible serious environmental and health consequences.

Effect of bevel angle on the reflection coefficient from open unflanged pipes.

Pipes terminating in bevel angled cuts are popular for automotive and motorcycle exhaust systems. This letter provides measured reflection coefficients and end impedances obtained from two-microphone experiments using unflanged open-ended pipes with bevel angles of 0°, 30°, and 60° for 0.03 < ka < 0.27, where k is the acoustic wave number and a is the pipe radius. The measurements at 0° match classical pipe reflection coefficient results within uncertainty. However, as the bevel angle increases to 60°, the magnitude of the reflection coefficient decreases by 2%, the end reactance increases by 130%, and the end resistance increases by 24%.

Detection of active noise control on the standard motorcycle exhaust Supra X 125 D using PVC pipe technique form Y

This detection aims to obtain noise reduction on the supra X 125D motorcycle exhaust by using the Active Noise Control Method. The technique is done using a Y-shaped PVC pipe to be bolted on the exhaust, which then branch Y PVC is placed loudspeaker with impermeable conditions. The function of this loudspeaker is as a secondary noise to counter the primary noise of the sound of exhaust motorcycle Supra X 125D. The sound generator in this study is the ISD 4004 module, which serves to generate noise to counter the source noise. How this ISD 4004 module works is by recording source noise then recording the source noise and then reversed the phase 180° by phase reversing circuit. So that, the noise generated by the sound generator will hit the source noise and encounter or such as addition of two different phase of sound will result in noise reduction when detected at the end of the Y-shaped PVC pipe. Inverted phase reversed using feed-back resistor 1 kΩ and 2 kΩ input resistors, 16V capacitor 2500μf and as amplifier using ICL 7660 and TL 702 CP. Test results on the highest 1000 rpm rotation engine speed on the Z axis of 2 dB, and at the highest 2000 rpm rotation engine speed also occurs on the Z axis of 1.5 dB.

Fuel Economy and Volatile Organic Compound Exhaust Emission for Motorcycles with Various Running Mileages

The implementation of control measures for motorcycles in urban areas depends on the establishment of baseline measures for fuel economy and emission characteristics. In this study, the fuel economy of motorcycles was determined to be 34.7 ± 1.4, 32.6 ± 1.8 and 29.5 ± 2.5 km L–1 for regulation phase V, IV, and III motorcycles, respectively. For regulation phase V motorcycles, the average emission factor was 84.3 ± 40.9 g L–1 for CO, 29.4 ± 13.1 g L–1 for HC, 8.0 ± 2.3 g L–1 for NOx, and 2098 ± 109 g L–1 for CO2. A comparison of the fuel economy of regulation phase III and IV motorcycles with that of regulation phase V motorcycle showed reductions of 15% and 6.2%, corresponding to increases of 156% and 48% in CO emission, increases of 84% and 9% in HC emission, and decreases of 30% and 17% in NOx emission, respectively. Based on fuel economy, the emission factors of a total of 67 volatile organic compounds(VOCs) were 25.2 ± 8.0 g L–1 for a running mileage of 5,231 ± 4,353 km, with emissions increasing to 47.1 ± 19.8 g L–1 for a running mileage of 47,617 ± 8,568 km. The exhaust of VOC groups profiled included paraffins (38–45%), olefins (9.7–15%), aromatics (38–48%), and carbonyls (1.8–3.0%) for various running mileages. Toluene, isopentane, m,p-xylene, o-xylene, 1-butene, 1,2,4-trimethylbenzene, ethylbenzene, n-pentane, and benzene were the main VOCs in motorcycle exhaust. Regarding the ozone formation potential of VOCs, 1-butene, xylene, isoprene, toluene, 1,2,4-trimethylbenzene, propene, and 1-hexene were the most abundant species in motorcycle exhaust.

Morphologic and chemical composition of particulate matter in motorcycle engine exhaust.

Despite the fact that environmental pollution due to motorcycle exhaust gases reports a great increase, motorcycle production exhibits a great increase through the last years. Countries of Asia and Africa are reported to be the major regions where two-wheeled vehicles are a major transportation mode, with tens of millions of units sold per year. Motorcycle exhaust particles are considered to be the major contributor to environmental pollution due to their airborne dispersion, containing great amount of polycyclic aromatic hydrocarbons (PAHs). This study aims at reporting an objective analysis of the main sources of the ambient air pollution as also particle size distribution and chemical composition analysis of particulate matter originated from the exhausts of two-wheeled vehicles used in the territory of Vladivostok, Russia. Various types of two-wheeled vehicles were examined (motorcycles, ATVs, scooters and wet bikes) using different types of engine and fuel system. Experimental results showed that there was no clear relation to the particle size distribution with the engine displacement of motorcycle and the number of strokes and the fuel system. Instead, there were reported two clear assumptions. The first one is that regarding to the motorcycle brand, a few samples did not exhibit a great percentage of PM10 fraction. The second one is that more modern vehicles, that have a harmful gas afterburning system, are usually the source of an increased percentage of PM10 emitted particles. At last, it should be mentioned that the laser particle size analysis method is capable of determining the particle sizes after their agglomeration whereas the optical morphometry method allows to determine the real particle size of emissions. In conclusion, it can be pointed out that the agglomeration of particles can lead to the reduction in the toxicity of particles emissions originated from two wheeled-vehicles.

Output voltage characteristic of heat pipe sink thermoelectric generator with exhaust heat utilization of motorcycles

Nowadays the great challenge to energy engineers is how to develop new and renewable energy sources to reduce the use of fossil fuels. In this direction, the research focuses on the recycle of wasted heat energy on a motorcycle exhaust gas into electrical energy using the concept of seed back. Recycle energy using this concept on a motorcycle is done because the bike has the energy efficiency of ± 35 – 40 % while the rest were dumped unceremoniously in the form of heat energy that is issued through the exhaust. This research aims to know the characteristics of the output voltage heat pipe sink thermoelectric generator utilizing waste heat of the motorcycle. This research has been done on the measurement of the output voltage is generated by the thermoelectric module series TECI-12706B type SP1848-27145 SA as a heat pipe sink thermoelectric generator to produce electrical energy. This research was conducted to know the output voltage from 4 thermoelectric modules arranged in series or parallel. furthermore this thermoelectric generator will be the main energy source for SSUPER-BT devices. Stages of the research done by performing laboratory and road testing. In laboratory testing, simulation of thermoelectric generator made using aluminium rods contain Heater. two sides of the aluminium coupled to thermoelectric modules, heat pipe and CPU fan. in each experiment, the thermoelectric modules strung together in series or in parallel. The results showed on the TEGs with 4 thermoelectric modules in series were able to produce higher output voltage and current compared to TEGs with 2 thermoelectric modules with output voltage reaching 15.7 volts and 7.7 volts respectively. The TEGs circuit with 4 thermoelectric modules produces 72.6% greater power than TEGs with 2 thermoelectric modules.

Varied dose exposures to ultrafine particles in the motorcycle smoke cause kidney cell damages in male mice.

Ultrafine particles (UFPs) are one of motorcycle exhaust emissions which can penetrate the lung alveoli and deposit in the kidney. This study was aimed to investigate mice kidney cell physical damage (deformation) due to motorcycle exhaust emission exposures. The motorcycle exhaust emissions were sucked from the muffler with the rate of 33 cm3/s and passed through an ultrafine particle filter system before introduced into the mice exposure chamber. The dose concentration of the exhaust emissions was varied by setting the injected time of the 20s, 40s, 60s, 80s, and 100s. The mice were exposed to the smoke in the chamber for 100 s twice a day. The impact of the ultrafine particles on the kidney was observed by identifying the histological image of the kidney cell deformation using a microscope. The exposure was conducted for 10 days. The kidney observations were carried out on day 11. The results showed that there was a significant linear correlation between the total concentration of ultrafine particles deposited in the kidneys and the physical damage percentages. The increased concentrations of ultrafine particles caused larger cell deformation to the kidneys.

Analisis Sifat Fisik dan Mekanik Sambungan Las Oxy-Acetylene pada Pelat Baja Karbon Rendah dengan Variabel Nyala Torch Karburasi

&lt;p&gt;Oxy-acetylene welding is widely used in small workshops for car body repair, automobile and motorcycle exhaust, and other improvements using a maximum temperature of 3000oC that can not be done through another process. The purpose of this study was to analyze the effect of torque oxyacetylene flame carburizing on the physical-mechanical properties of low carbon steel plate welding joints. The method employed by using a low carbon steel plate 2 (two) pairs in a butt weld immension of 300 mm x 75 mm x 1 mm. After welding with oxy-acetylene in torch carburizing flame, the specimens were examined through physical observation including microstructure and echanical properties. Micro hardness vickers (VHN) was used to evaluate the harness and tensile properties was determine using the universal testing machine. In the microstructure testing, there is a pearlite and ferrite whose become different dimensions as it is affected by the heat and air pressure of the weld. The result of tensile strength specimen A 174,6 N/mm2 and specimen B 157,65 N/mm2. While the vickers test obtained the highest hardness that is 152.5 VHN in the welding area&lt;em&gt;.&lt;/em&gt;&lt;/p&gt;

PENGARUH BAHAN BAKAR PREMIUM, PERTAMAX, PERTAMAX PLUS DAN VARIASI RASIO KOMPRESI TERHADAP KADAR EMISI GAS BUANG CO DAN HC PADA SUZUKI SHOGUN FL 125 SP TAHUN 2007

&lt;p&gt;The purpose of this research: (1) Investigated the motorcycle exhaust emissions Suzuki Shogun FL 125 SP in 2007 used premium,pertamax,and pertamax plus. (2) Investigated the motorcycle exhaust emissions Suzuki Shogun FL 125 SP in 2007 used variation of compression ratio. (3) Investigated the motorcycle exhaust emissions Suzuki Shogun FL 125 SP in 2007 used interaction premium,pertamax, pertamax plus, and variation of compression ratio.&lt;br /&gt;This research was used experimental methods.The research was measurement at the Laboratory of Automotive Mechanical Engineering Education Program, JPTK, FKIP, UNS Surakarta to the address on Ahmad Yani road no. 200 Kartasura. Test of CO and HC exhaust gas emissions was used a gas analyzer type STARGAS 898. The population in this research was a motorcycle Suzuki Shogun FL 125 SP in 2007 and the sample in this research was a motorcycle Suzuki Shogun FL 125 SP in 2007 with engine number: F4A1ID113687.&lt;br /&gt;Based on this researchcan be concluded: (1) The measurement premium fuel producedthe lowest emission in CO 3.884% by 9.1:1 compression ratio and the the lowestexhaust gas emission levels in 168 ppmby 9.1:1 compression ratio. (2) The measurement pertamax fuel produced the lowest exhaust gas emission levels in CO 3.237% by 9.5:1 compression ratio and the the lowest exhaust gas emission levels in 210 ppm by 9.5:1 compression ratio(3) The measurement pertamax plus fuel produces the lowest exhaust gas emission levels in CO 2.615% by 10.2:1 compression ratio and the the lowest exhaust gas emission levels in 237 ppm by 9.5:1 compression ratio&lt;/p&gt;

Evaluation of the viability of BEAS-2B cells exposed to gasoline engine exhaust with different particle sizes by air-liquid interface

Objective: To evaluate the viability of gasoline engine exhaust (GEE) with different particle sizes on human lung cell line BEAS-2B in vitro by air-liquid interface (ALI) . Methods: GEE were collected with a Tedlar bag and their particulate matter (PM) number, surface and mass concentration in three kind of GEE (filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter) were measured by two type of particle size spectrometer including TSI-3321 and SMPS-3938. Five groups were included, which divided into blank control group, clean air group, filtered automobile exhaust group, non-filtered automobile exhaust group and motorcycle exhaust without three-way catalytic converter group. Except the blank control group, BEAS-2B cells, cultured on the surface of Transwells, were treated with clean air or GEE by ALI method at a flow rate of 25 ml/min, 37 ℃ for 60 min in vitro. CCK-8 cytotoxicity test kit was used to determine the cell relative viability of BEAS-2B cells. Results: In the filtered automobile exhaust, non-filtered automobile exhaust and motorcycle exhaust without three-way catalytic converter, high concentrations of fine particles can be detected, but the coarse particles only accounted for a small proportion, and the sequence of PM concentration was motorcycle exhaust without three-way catalytic converter group> non-filtered automobile exhaust group> filtered automobile exhaust group (P<0.001) . Compared with the clean air group, the cell relative viability in the 3 GEE-exposed groups were significantly lower (P<0.001) . Among the comparisons of GEE exposure groups with different particle size spectra, the sequence of the cell relative viability was filtered automobile exhaust group >non-filtered automobile exhaust group> motorcycle exhaust without three-way catalytic converter group (P<0.001) . When took the clean air control group as a reference, the mean of the cell relative viability in the filtered automobile exhaust group, non-filtered automobile exhaust group and motorcycle exhaust without three-way catalytic converter group, was decreased by 26.34%, 36.00% and 49.59%, respectively. Conclusion: GEE with different particle size spectra could induce different levels of toxic effects to the human lung cells BEAS-2B by ALI. After lowering the concentration of particles in the GEE and using the three-way catalytic converter could obviously improve the survival rate of lung cells.

Analisis Nyala Torch Oksidasi Pada Oxy-Acetylene Terhadap Sifat Fisik Dan Mekanik Sambungan Las Pelat Baja Karbon Rendah

Oxy-acetylene welding is widely used in small workshops for car body repair, automobile and motorcycle exhaust, and other improvements using a maximum temperature of 3000 o C that can not be done through another process. The purpose of this study was to analyze the effect of torque oxy-acetylene flame on the physical-mechanical properties in welding connection low carbon steel plates . The method used by using a low carbon steel plate 2 (two) pairs in a butt weld dimmension of 300 mm x 75 mm x 1 mm. After welding with oxy-acetylene in torch oxidation flame, the specimens were examined through physical observation including microstructure and mechanical properties. Micro hardness vickers was used to evaluate the hardness. Tensile properties was determine using the universal testing machine. In the microstructure testing, there is a pearlite and ferrite whose become different dimensions as it is affected by the heat and air pressure of the weld. Mechanical testing that is tensile test obtained yieldpoint of the specimen A 125,17 N/mm 2 and specimen B 126,55 N/mm 2 . The result of tensile strength specimen A 166,35 N/mm 2 and specimen B 169,76 N/mm 2 . While the vickers test obtained the highest hardness that is 152.5 VHN in the welding area, and the lowest hardness number is 124,9 VHN in the heat affected zone.

The use of a 0.20 μm particulate matter filter decreases cytotoxicity in lung epithelial cells following air-liquid interface exposure to motorcycle exhaust

This study was designed to investigate whether the use of a 0.20 μm particulate matter (PM) filter reduced the cytotoxicity induced by motorcycle exhaust (ME), a mixture of gases and particles, in lung epithelial cells cultured in air-liquid interface (ALI) inserts. The concentrations of PM, carbon monoxide, carbon dioxide, total hydrocarbons (THC), total volatile organic compounds, and nitrogen oxides in both filtered ME (fME) by a 0.20 μm filter and non-filtered ME (non-fME) were measured. Lung epithelial cells were exposed to clean air, fME, or non-fME in the ALI chamber. Cell relative viabilities (CRV) and the reactive oxygen species (ROS) generation were determined. Our results revealed that PM2.5 was the main compound of PM in ME. After filtration, PM and THC levels were significantly reduced, as compared with non-fME. When compared with the clean air exposed group, the CRV in both fME and non-fME-exposed group was significantly reduced (p < 0.001), while their ROS generation were markedly increased (p < 0.001). When compared with non-fME-exposed group, the CRV and ROS generation were significantly improved following fME exposure (p < 0.05). As a result, of PM and THC concentrations were decreased approximately 90% and 22.71%, respectively, the CRV was improved from 40.4% (non-fME) to 55.7% (fME), and the increased ROS generation by non-fME was decreased about 51.6%. When BEAS-2B cells were exposed to fME, a time-dependent reduction in CRV was observed. In conclusion, our findings suggest that ME-exposure in the ALI system induces cytotoxicity and oxidative stress responses. The addition of a 0.20 μm PM filter significantly modifies the particulate composition in PM and the concentration of THC, and shows protective effects by improving the survival of exposed lung epithelial cells and reducing the ROS generation. Therefore, emission factors such as different size of PM and THC from motorcycles may play a role in ME-induced toxicity.

Fabrication of Bi–Sb–Te Thermoelectric by Cold-Pressed Sintering for Motorcycle Exhaust.

This study was conducted on the Bi–Sb–Te thermoelectric material which is cold-pressed Sintering under 750 Mpa to make square thermoelectric pairs with size 8.2 mm × 8.2 mm and thicknesses 0.8 mm and 1.5 mm. The zone melting method was used to acquire P-type thermoelectric material Bi0.4Sb1.6Te3 and N-type thermoelectric material Bi2Te2.5Se0.5. At temperature 383 K, the measured Seebeck coefficient of Bi0.4Sb1.6Te3 is 222 μV/K, and its thermoelectric figure of merit ZT is 1.35. At temperature 400 K, the measured Seebeck coefficient of Bi2Te2.5Se0.5 is 210 μV/K, and its thermoelectric figure of merit ZT is 1.13. Using Solder paste Sn42Bi58 and copper electrode plate are in series connection with 16 pieces of P/N thermoelectric material to form thermoelectric modules. The thermoelectric module is actually pasted on the motorcycle waste heat source to be evaluated the performance, making the cold-end temperature dissipation heat can enhance the temperature difference between it so as to increase the output power. Increasing the leg thickness of thermoelectric module and making the about 35 °C temperature-difference of those can obviously enhance the performance of in terms of its voltage, its thermoelectric figure of merit ZT and output power of the thermoelectric modules.

Air pollutants and toxic emissions of various mileage motorcycles for ECE driving cycles

Motorcycles were selected to determine their fuel consumption and exhaust emissions following ECE driving cycles. Exhaust constituents including CO2, CO, NOx, total hydrocarbons (THC) and hydrocarbon species (27 paraffins, 9 olefins, 16 aromatics and 15 carbonyls) were investigated for this work. The age of 10– 90% of the selected motorcycles ranged from 2.5 to 12.4 years, and their mileage ranged from 5400 to 39,300 km. CO emission ranged from 1.4 to 6.4 g/km (median value: 2.98 g/km), THC from 0.41 to 1.54 g/km (median value: 0.98 g/km), NOx from 0.16 to 0.28 g/km (median value: 0.21 g/km), CO2 from 58.9 to 62.2 g/km (median value: 60.5 g/km) and fuel consumption from 30.7 to 36.4 km/L (median value: 33.4 km/L), corresponding to the percentage cumulative data from 10 to 90% of the selected motorcycles. Results indicated that the motorcycle exhaust emission and fuel consumption depended on their mileage and ages. An increase in mileage of 1000 km resulted in an increase of 103 mg for CO emission and 14.7 mg for hydrocarbon emission and a reduction of 1.52 mg NOx emission and 0.11 km per liter fuel consumption. For various VOC groups, a mileage increase of 1000 km corresponding to the increased exhaust emission of paraffins was 6.71 mg, olefins 1.90 mg, aromatics 7.04 mg, carbonyls 0.283 mg and 67 VOC species 15.9 mg. Fuel consumption and emissions of CO and hydrocarbon increased in motorcycles over the guaranteed mileage of 15,000 km.

Criteria Pollutants and Volatile Organic Compounds Emitted from Motorcycle Exhaust under Various Regulation Phases

ABSTRACTEstablishment of emission standards is an important measure for controlling vehicle exhaust. This study examined the emission factors of air pollutants from 40 four-stroke motorcycles of various emission standard phases, ages, and mileage. Based on the emission standards, the motorcycles were divided into three groups (Phases III, IV and V). Regulated air pollutants (CO, HC, and NOx), CO2, and 52 volatile organic compounds were evaluated on a chassis dynamometer using the Economic Commission for Europe (ECE) test cycle. The sequence of CO and HC emission factors was Phase III > Phase IV > Phase V, and their ratios of emission factor of Phase IV to Phase III and Phase V to Phase III were 0.66 and 0.42 for CO and 0.61 and 0.57 for HC, respectively. Exhaust from motorcycles deteriorates with age and mileage. For NOx emission, the sequence of emission factor was Phase V > Phase IV > Phase III. However, the relationship was insignificant between CO2 emission factor and motorcycle age. The total VOC emissions of Phase V motorcycles were the lowest (0.59 g km–1) among all test motorcycles; however, the fraction of VOC groups was similar among all test motorcycles regardless of different regulation phases. For organic air toxics, the emissions of benzene, toluene, ethylbenzene, and xylene (BTEX) decreased by 37–58% and 44–62%, respectively, for Phases IV and V motorcycles compared to those of Phase III motorcycles. Results also indicated that the ozone formation potential (OFP) was high in older motorcycles with high mileage. In summary, emissions of CO, HC, total VOCs, BTEX, and OFP may decrease with the decrease of motorcycle age and mileage as well as the phase of emission standards. The results implied that tightening emission standards indeed encourages motorcycle manufacturers to improve engine technology and combustion efficiency, resulting in reduced emission of air pollutants, except NOx emission in this study.

Design and Preparation of Bi-Sb-Te Alloy Thermoelectric Power Generation from Motorcycle Exhaust

This study was conducted on design and preparation of the variable compositions bismuth antimony telluride (BiSbTe) alloys by mechanically alloying and the powders sintering to form the thermoelectric alloy materials. The powder of thermoelectric material is coldpressed under 766.4Mpa to make square thermoelectric pairs with size 8.2mm×8.2mm and thicknesses 0.8mm and 1.5mm. The zone melting method was used to acquire P-type thermoelectric material Bi0.4Sb1.6Te3 and N-type thermoelectric material Bi2Te2.55Se0.45. At temperature 381K, the measured Seebeck coefficient of Bi0.4Sb1.6Te3 is 223μV/K, and its thermoelectric figure of merit ZT is 1.36. At temperature 400K, the measured Seebeck coefficient of Bi2Te2.55Se0.45 is 206μV/K, and its thermoelectric figure of merit ZT is 1.03. Solder paste Sn42Bi58 and copper electrode plate are in series connection with 16 pieces of P/N thermoelectric material to form thermoelectric modules. The generating performance of a thermoelectric module is evaluated in terms of its voltage, current and output power of the thermoelectric modules.

Assessing the Application of the Flexible Joint in the Exhaust Pipe and Braided Wire Damper in Muffler on the Sound Emitted by the CG125 Motorcycle Exhaust

Background: In recent years, noise pollution has become a serious problem for residents in urban areas. Motorcycles have an important role in producing noise. Objectives: This study aimed to reduce motorcycle noise by using flexible joint in tailpipe and braided wire dumpers at its exhaust. Materials and Methods: In this study, SAE J1287 procedure was used for noise measurement of Amico CG125 motorcycle. Also, for measuring the temperature and pressure of exhausted gas, JIS B 8006 and JIS B 8007 methods were used, respectively. The instruments used for measuring noise, temperature, and pressure of exhausted gas were CEL-6X0 sound level meter, detector of exhaust gas analyzer, Pitot tube, and incline manometer, respectively. Flexible joint and braided wire damper were also prepared (Erteash Gostar Peyman Company). Results: By using this new exhaust at speed levels of 1000, 2000, 3000, 4000, and 5000 rpm, we had respectively 3.9, 6.8, 7.4, 5.6, and 5 dBA decreases in total sound level pressure. Conclusions: Use of flexible joint in the exhaust system leads to conversion of linear vibration to non-linear one, resulting in significant reduction of noise levels.

Cambios epidemiológicos en niños quemados, a 10 años de seguimiento

IntroductionThe aim of the study was to compare the incidence and epidemiological characteristics of burns suffered by children in a district of Santiago of Chile over a period of ten years. Patients and methodAn analytical study was conducted by checking through the medical files of children under 15 years of age from Pudahuel district who were admitted with burns to the Santiago Aid to Burned Children Corporation (COANIQUEM) during 2011. A comparison was made with the results obtained in a similar study performed in the same district in 2001. ResultsIn 2011, 440 children were admitted, with an incidence rate of 700/100,000 <15 years old (95% CI: 635-765), a decrease of 25% compared to 2001(Incidence rate of 933/100,000; 95% CI: 856-1010). There were 52% males, 64.5% under 5 years old of age, 88% burned at home, or at other houses where they are been taking care of. There was a significant change in the causative agent, and included, increasing by their relative importance; hot objects (27.1%). The mechanism that mostly increased in occurrence were contact with stoves or heaters, and also emerge that caused by hair iron, and motorcycle exhaust. The most common location was the hand, increasing by 30.8%, and 66.4% showed an extension of the burn of <1% total body surface area (2001, 61%). A significant decline of 54% of deep burns was observed, and 23.2% were admitted to rehabilitation, a similar proportion to 2001. The rate of hospitalization and/or skin graft decreased from 104/100,000 to 62/100,000<15 years old (95% CI: 43-82). ConclusionsBurns incidence has decreased. Hot objects are now the main causal agent. The decrease in the rate of hospitalization and/or graft indicates a lower severity of burns.

Prediction of Fatigue Strength of Motorcycle Exhaust System Considering Vibrating and Thermal Stresses

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;A method applicable in the design stage to predict fatigue strength of a motorcycle exhaust system was developed. In this prediction method, a vibrating stress, thermal stresses, stresses resulting from the assembling of the exhaust system components and a deterioration of fatigue strength of materials originated from high temperature were simultaneously taken into account. For the prediction of the vibrating stress, flexible multibody dynamics was applied to get modeling accuracy for vibration characteristics of the entire motorcycle and the exciting force delivered from engine vibrations. The thermal conduction analysis and the thermal deformation analysis based on finite element method (FEM) were applied for the prediction of thermal stresses in the exhaust system components. The temperature distribution on the surfaces of the exhaust system components is required for calculations of the thermal stresses. The heat transfer analysis, which was composed by combing a one-dimensional (1D) engine cycle simulation and an air flow simulation around the vehicle by 3D-CFD, was used for the estimation of temperature distributions. To validate the developed method, the correlations between the simulations and the actual measurements were analyzed for the vibrating stress, the temperature distribution, the thermal stresses and the fatigue safety factor. High correlations were yielded between them proving the validity of the new method.&lt;/div&gt;&lt;/div&gt;