scholarly journals The performance test of the car catalytic converter in the conditions of urban operation

2020 ◽  
Vol 164 ◽  
pp. 03018 ◽  
Author(s):  
Aleksandr Ivanov ◽  
Oleg Abyzov ◽  
Yurii Galyshev ◽  
Victor Rumyantsev
Keyword(s):  
Urban Areas ◽  
Performance Test ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Continuous Operation ◽  
Spark Ignition Engines ◽  
Warm Up ◽  
Harmful Emissions ◽  
Before And After ◽  
Operational Factors

In the conditions of continuous operation of a car tests of its engine for compliance with the declared environmental class on specialized test benches seem to be quite costly and laborious. Given this circumstance, in this paper a simplified method for verifying the operability of converters is proposed including the assessment of the influence of certain operation modes and some operational factors on the amount of hydrocarbons and carbon monoxide emissions. Efficiency of the converter was estimated by comparing the experimental data on the emissions of these toxic components in the exhaust system before and after the converter. To test the efficiency of the converter, the cold start and warm-up modes of the engine were selected and investigated, as well as several modes close to those typical for testing the engine and car in urban areas according to the European Driving Cycle. As operational factors, typical malfunctions were investigated that often occur during the operation of an engine and significantly increase the amount of harmful emissions. A criterion is proposed for evaluating the performance of the converter and recommendations are given to increase the efficiency of the converter to meet the certain emission standards for cars with spark-ignition engines.

scholarly journals Feasibility of a Dual-Fuel Engine Fuelled with Waste Vegetable Oil and Municipal Organic Fraction for Power Generation in Urban Areas

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
L. De Simio ◽  
M. Gambino ◽  
S. Iannaccone
Keyword(s):  
Vegetable Oil ◽  
Urban Areas ◽  
Process Efficiency ◽  
Exhaust Emission ◽  
Dual Fuel ◽  
Spark Ignition Engines ◽  
Organic Fraction ◽  
Waste Vegetable Oil ◽  
Performance And Emissions ◽  
Cogeneration System

Biomass, in form of residues and waste, can be used to produce energy with low environmental impact. It is important to use the feedstock close to the places where waste are available, and with the shortest conversion pathway, to maximize the process efficiency. In particular waste vegetable oil and the organic fraction of municipal solid waste represent a good source for fuel production in urban areas. Dual fuel engines could be taken into consideration for an efficient management of these wastes. In fact, the dual fuel technology can achieve overall efficiencies typical of diesel engines with a cleaner exhaust emission. In this paper the feasibility of a cogeneration system fuelled with waste vegetable oil and biogas is discussed and the evaluation of performance and emissions is reported on the base of experimental activities on dual fuel heavy duty engine in comparison with diesel and spark ignition engines. The ratio of biogas potential from MSW and biodiesel potential from waste vegetable oil was estimated and it results suitable for dual fuel fuelling. An electric power installation of 70 kW every 10,000 people could be achieved.

Impact of adenotonsillectomy on the quality of life of patients operated on at the Hospital de Clínicas, Paraguay

2021 ◽  
pp. 1-7
Author(s):  
Carlos Mena Canata ◽  
Rebeca Noemí Ruiz Vallejos
Keyword(s):  
Quality Of Life ◽  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Rural Areas ◽  
Urban Areas ◽  
Obstructive Sleep ◽  
Significant Difference ◽  
Before And After ◽  
The Impact

The objective of this study is to determine the impact of adenotonsillectomy on the quality of life of postoperative patients.The study is observational, cross-sectional, and retrospective. The files of all postoperative adenotonsillectomy patients in Otorhinolaryngology Service, Hospital de Clínicas, San Lorenzo Paraguay. The Obstructive sleep apnea – 18 questionnaire (OSA 18) was applied, asking patients about symptoms before and after surgery. An effective sample of 143 postoperative patients was obtained. The average age was 6.05 ± 2.08 years, 55.10% (81) were male and 44.89% (66) were female, 65.30% (96) were from urban areas and 34.69% (51) from the rural areas. The t test was performed for means of two paired samples, comparing the results of the Obstructive sleep apnea – 18 questionnaire surveys before and after surgery which presented a significant difference (p <0.05) with a tendency to improve the quality of life after surgery. It has been shown that there is a significant difference, a considerable improvement in the quality of life of patients after adenotonsillectomy.

scholarly journals The Effect of Soil Reinforcement on the Stress and Strain Field Around Underground Square-Shaped Areas and its Internal Lining Efforts in Urban Areas

2018 ◽  
Vol 4 (11) ◽  
pp. 2756 ◽  
Author(s):  
Alireza Darvishpour ◽  
Asadollah Ranjbar ◽  
Amirmohammad Amiri
Keyword(s):  
Urban Areas ◽  
Underground Structure ◽  
Physical Modelling ◽  
Soil Reinforcement ◽  
Soil Parameters ◽  
Stress And Strain ◽  
Horizontal Distance ◽  
Underground Structures ◽  
Finite Element Software ◽  
Before And After

The passage of underground structures from the bottom of the structures on the ground causes a change in the stresses and strains created in the structure as well as the soil environment surrounding the tunnel due to the existence of an interaction between these two sides. In this way, the existence of the surface structure leads to a change in the strain and stress conditions around the tunnel, and in contrast, the tunnel also leads to a change in the stress and settlement around the structures. Therefore, such a reciprocal behavior is very important. In this research, with the help of Abaqus finite element software, two main possible conditions are considered: the creation of an underground structure in the presence of the superstructure, as well as the reverse state of the concept of constructing a building in the state in which the underground structure already exists. One of the subjects studied in this research is the physical modelling effect of the structure, rather than the effect of its wide load on the ground. Other parameters considered in this research are the number of story, the depth of the tunnel, the width of the tunnel, the thickness of the lining, the effect of changes in the soil parameters in the depth and the horizontal distance of the tunnel center from the building center. The results of this research are validated based on the results obtained by other researchers. According to the results obtained in this research, by the increase of the distance between the tunnel center and structure center and depending on the stiffness of the tunnel lining, significant asymmetric stresses are created in the superstructure. The construction of the structure before and after the tunnel construction can affect the unsymmetrical settlement of the structure The stress and strain created in the lining of the tunnel and the surrounding area are also different due to the amount of mobilized force in the reinforcements.

scholarly journals Effects of the exhaust gas heat recovery system with a plate heat exchanger on the warm-up performance characteristics of the gasoline engine

2018 ◽  
Vol 7 (2.12) ◽  
pp. 136
Author(s):  
Chan JungKim ◽  
Sank Wook-Han ◽  
Ki Hyun Kim ◽  
Moo Yeon Lee ◽  
Gee Soo Lee
Keyword(s):  
Heat Exchanger ◽  
Fuel Economy ◽  
Heat Recovery ◽  
Exhaust System ◽  
Plate Heat Exchanger ◽  
Exhaust Gas ◽  
Warm Up ◽  
Plate Heat ◽  
Recovery System ◽  
Heat Recovery System

Background/Objectives: To meet the regulations for the fuel economy, an EHRS (Exhaust gas Heat Recovery System, which was installed within the vehicle exhaust system and recovered the heat from the exhaust gas, were needed. The EHRS enabled the engine to achieve the fast warm-up performance for reducing friction loss during the cold start.The objective of this paper was to investigate the effects of the design parameters of the EHRS with a plate heat exchanger on the warm-up performance of a gasoline engine.Methods/Statistical analysis: The EHRS with the plate heat exchanger was manufactured and installed behind the catalyst in the exhaust system of the gasoline direct injection engine. The experimental study and multi-disciplinary analysis were carried out to investigate the effects of the EHRS on the warm-up performance of the engine, such as the coolant temperature, the exhaust gas temperature and the recovery heat at idle condition and the step-load condition.Findings: Because the recovery of heat was about 1. 7 kW at idle condition, the effect of the EHRS on the warm-up performance was negligible. However, due to 17.2 kW of the recovery of heat at the stepload condition of T=140 Nm at N=2,400 rpm, the EHRS enabled to shorten the warm-up time by 548 s comparison that of the base engine.Improvements/Applications: The fuel economy will be expected to be improved through an EHRS, which provides the improved combustion in the warm-up phase and a decrease in friction loss.  

scholarly journals Effect of noise on fatigue: correlation between the subjective and objective indicators

2019 ◽  
Author(s):  
Jalil Derakhshan ◽  
Majid Moatamedzadeh ◽  
Rostam Golmohammadi ◽  
Mohammad Babamiri ◽  
Maryam Farhadian
Keyword(s):  
Performance Test ◽  
Continuous Performance Test ◽  
Cross Sectional Study ◽  
The Body ◽  
Continuous Performance ◽  
Cross Sectional ◽  
Measurement Results ◽  
Before And After ◽  
Fatigue Measurement ◽  
Objective Indicators

Introduction: Fatigue is the exhaustion of the body or spirit that can be caused by stress, excessive work, drug use, physical or mental illness. Fatigue is a factor in reducing productivity and incidents. Therefore, measuring fatigue is important. The aim of this study was to determine the fatigue measurement based on subjective and objective indices. Method: A cross-sectional study was performed on 120 male and female students. By simulating the real environment of each person in the 50 and 70dB pressure levels for 40 minutes, before and after exposure to noise, the amount of mental fatigue was measured using the subjective index Visual Analog Scale (VAS) and the objective index continuous performance test (CPT).  The results were analyzed using paired t-test and Spearman correlation coefficient in SPSS 20 software. Results: Measurement results with both self-declaration scale and continuous performance test showed that mental exhaustion  was increased significantly after exposure to the mentioned pressure level, but the results of two methods were not consistent with each other. Conclusion: Considering that the VAS self-declaration scale is a subjective method, it seems that the mismatch of the two methods is more related to the ineffectiveness of this scale. Therefore, it is suggested that re-examination has to be done with more precise methods such as electroencephalogram.

Environmental indicators of modern land vehicles

2020 ◽  
Keyword(s):  
Control System ◽  
Nitrogen Oxides ◽  
Greenhouse Effect ◽  
Power Plants ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Environmental Indicators ◽  
Solid Particles ◽  
Particulate Filter ◽  
Land Vehicles

Models and mechanisms for the formation of soot and nitrogen oxides during the combustion of hydrocarbon fuels of power plants of vehicles have been developed. Models of numerical modeling and calculation of solid particles, nitrogen oxides and urea of diesel engines are formulated. The potential for the formation of a greenhouse effect is briefly described. The regularity of the relationship between nitrogen oxides and soot was revealed. A schematic diagram of the oxidizing neutralizer and particulate filter of modern diesel is given. The diagram of the urea supply system and the urea atomization module in the engine exhaust system is given. The scheme of the control system for catalytic neutralization of nitrogen oxides is given. A comparative assessment of nitric oxide reductants is given. An assessment of the technical and environmental effectiveness of the system for reducing the toxicity and smoke content of modern engines is given. Keywords greenhouse effect, smokiness, solid particles, urea, soot, diesel, acetylene, soot filter, catalytic Converter, nitrogen oxides, models for calculating soot and nitrogen oxides, urea supply module, control system

Numerical and experimental investigations of the early injection process of Spray G in a constant volume chamber and an optically accessible DISI engine

2021 ◽  
pp. 146808742110394
Author(s):  
Andrea Pati ◽  
Davide Paredi ◽  
Cooper Welch ◽  
Marius Schmidt ◽  
Christopher Geschwindner ◽  
...  
Keyword(s):  
Direct Injection ◽  
Constant Volume ◽  
Experimental Investigations ◽  
Spark Ignition Engines ◽  
Charge Motion ◽  
Injection Process ◽  
Constant Volume Chamber ◽  
Before And After ◽  
The Individual ◽  
Intake Flow

In this work, the Engine Combustion Network Spray G injector was mounted in the Darmstadt optical-accessible engine to study phenomena typical of multi-hole, early direct-injection events in spark-ignition engines characterized by tumble flow charge motion. Dedicated experimental measurements of both in-cylinder spray morphology and flow velocities before and after the injection process were carried out to assess the adopted numerical setup under real engine conditions. A dynamic secondary breakup model from the literature was coupled with an atomization multi-motion regime model. The model was validated against state-of-the-art ECN Spray G experiments for a constant-volume chamber under low evaporating condition. Then, the simulation of the spray injection in the engine was carried out and the achieved results were compared against the experimental data. Overall, good agreement between experiments and simulations was observed for the spray morphology and velocity fields in both cases. With reference to engine calculations the intake flow was seen to induce spray asymmetry. A partial vortex generated during the intake phase on the tumble plane interacts with the spray, developing into a full vortex which induces an upward flow that stabilizes the spray. The upward flows below the intake valve increase the dilution of the plume outside the tumble plane, which therefore exhibits reduced penetration. Moreover, the intake valves protect from the energetic intake flow the recirculation vortex generated at the tip of the plumes that lie outside the tumble plane. The intake flow helps fuse the vapor fuel clouds of the individual plumes near the injector tip, obtaining a vapor fuel with a shape like that generated by a horseshoe multi-hole injector. Finally, a phenomenological model of the interaction between the multi-hole injector jets and the engine intake flow was introduced to describe the spray evolution in a typical DISI engine.

Statistical analysis of earthquake debris extent from wood-frame buildings and its use in road networks in Japan

2020 ◽  
Vol 36 (1) ◽  
pp. 209-231
Author(s):  
Luis Moya ◽  
Erick Mas ◽  
Fumio Yamazaki ◽  
Wen Liu ◽  
Shunichi Koshimura
Keyword(s):  
Urban Areas ◽  
Road Networks ◽  
Decision Makers ◽  
Aerial Photos ◽  
Geometrical Properties ◽  
Frame Buildings ◽  
Before And After ◽  
Wood Frame ◽  
Collapsed Buildings ◽  
The Relationship

Debris scattering is one of the main causes of road/street blockage after earthquakes in dense urban areas. Therefore, the evaluation of debris scattering is crucial for decision makers and for producing an effective emergency response. In this vein, this article presents the following: (1) statistical data concerning the debris extent of collapsed buildings caused by the 2016 Mw 7.0 Kumamoto earthquake in Japan; (2) an investigation of the factors influencing the extent of debris; (3) probability functions for the debris extent; and (4) applications in the evaluation of road networks. To accomplish these tasks, LiDAR data and aerial photos acquired before and after the mainshock (16 April 2016) were used. This valuable dataset gives us the opportunity to accurately quantify the relationship between the debris extent and the geometrical properties of buildings.

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