IVE Model Research Articles

GPS Data and Machine Learning Tools, a Practical and Cost-Effective Combination for Estimating Light Vehicle Emissions.

This paper focuses on the emissions of the three most sold categories of light vehicles: sedans, SUVs, and pickups. The research is carried out through an innovative methodology based on GPS and machine learning in real driving conditions. For this purpose, driving data from the three best-selling vehicles in Ecuador are acquired using a data logger with GPS included, and emissions are measured using a PEMS in six RDE tests with two standardized routes for each vehicle. The data obtained on Route 1 are used to estimate the gears used during driving using the K-means algorithm and classification trees. Then, the relative importance of driving variables is estimated using random forest techniques, followed by the training of ANNs to estimate CO2, CO, NOX, and HC. The data generated on Route 2 are used to validate the obtained ANNs. These models are fed with a dataset generated from 324, 300, and 316 km of random driving for each type of vehicle. The results of the model were compared with the IVE model and an OBD-based model, showing similar results without the need to mount the PEMS on the vehicles for long test drives. The generated model is robust to different traffic conditions as a result of its training and validation using a large amount of data obtained under completely random driving conditions.

Emissions and trajectories of atmospheric pollutants from mobile sources in a Colombian intermediate city

In this study, the emissions of criteria pollutants and greenhouse gases from mobile sources in the main streets of the city of Valledupar were estimated. A vehicular characterization of the streets studied was carried out, and the IVE model was implemented to estimate the emissions generated by automobiles; subsequently, scenarios of atmospheric transport routes of pollutants were analyzed with the HYSPLIT model. The results showed that in the case of pollutant criteria, motorcycles emitted the highest amount of CO and PM10, and private cars the highest SOx and NOx emissions. For GHGs, private cars emitted the highest amount of CO2 and N2O, while motorcycles emitted the highest amount of CH4. The trajectory scenarios for the days of the study were carried out during the peak hours of vehicular circulation, implementing meteorological data from the WRF model. The trajectories were evaluated in rainy periods of 2021 and 2022 and in the dry period of 2022. In the rainy period, it was observed that the transport routes of the pollutants were directed in a greater proportion towards the NE direction and the dry period towards the SE direction. With this, it was possible to determine which areas of the city could be the most affected by vehicle emissions from the roads studied.

A high resolution vehicular emissions inventory for Ecuador using the IVE modelling system

Air pollutants caused by traffic has become a topic of global interest due to its impact on human health and the environment, making high-resolution emission inventories effective mechanisms for air quality management. This study proposes the development of a high-resolution inventory of vehicle emissions in Ecuador using the IVE modelling system, which was developed for its use in third world countries. The required data was collected in several provinces of the country, determining vehicle intensity, driving patterns, departure patterns, environmental variables, and vehicle technologies. To have a greater data representation, vehicles were classified into five categories according to their size, in addition three types of roads were also considered (Highways, Roads and Residential). The database was used to determine the specific power of the engine and “bines”, variables that together with the emission factors are part of the calculation of IVE model. Atmospheric pollutants such as CO, VOC's and VOC Evap, NOx, SOx, PM, CO2 and CH4 were also considered, it has been identified that in Ecuador 3.66 million tons of CO were produced in 2015, with trucks representing road transportation being the largest pollutants with approximately 57.2% of the whole total. Through the spatial disaggregation it was possible to identify that the most critical areas, in terms of generation of atmospheric pollutants, are in the most densely populated cities of the country such as Quito and Guayaquil, as well as in areas near seaports and state roads, from 6:00 h, 12:00 h and 18:00 h the hours of the day in which the largest number of emissions are produced. At the end of the study, it was discovered that trucks were the ones that generated the highest emissions of atmospheric pollutants in Ecuador.

Characterization of Air Pollution in Pre-COVID 19 Time Using the IVE Model Applied to Mobile Sources in Urban Areas

In this article we present the design of effective control strategies (IVE Model), to predict atmospheric pollutants, greenhouse gases and toxins, from mobile sources, made up of 800 motorized vehicles, obtained from the records of the transport office of the Provincial Municipality of Ica. through an inventory of emissions from mobile sources, emission factors, activity and distribution of the vehicle fleet. The results obtained are Carbon Monoxide (CO, 23235.23 t/year), Volatile Organic Compounds (VOC: 12123.55 t / year), Nitrogen Oxides (Nox: 361.76 t/year), Evaporative Volatile Organic Compounds (COVevap: 455.2 t / year), Particulate Material (PM: 361.76 t / year) and Sulfur Oxides (Sox: 50.75 t / year). Where the highest CO emissions are cars and motorcycles, representing 45.72% and 36% of the total CO emissions released in the study area. It is concluded that prevention measures and actions such as transport management, control of vehicular emissions, promotion of the use of clean fuels, as a way of mitigating the atmospheric pollutants that could be generated, be established.

Real-world evaluation of driving behaviour and emission performance of motorcycle transportation in developing countries: A case study of Isfahan, Iran

The present study aims at a real-world assessment of the driving behaviour and exhaustive emission performance of motorcycle (MC) driving in a middle-sized city of a developing country, i.e. Isfahan, Iran. We developed the Isfahan Motorcycle Driving Cycle (IMDC) using comprehensive data collection and then compared it with the available overseas MCDCs and DC of local LDVs. Onboard experiments were also conducted on 20 test motorcycles to analyze emission performance, emission characteristics, and combustion quality of motorcycles under real-world conditions. IVE model was used to estimate the MC emission factors (EFs) according to the real-urban conditions, but it was first adjusted to the real-world measurements. Results show that MC EFs steadily decrease with vehicle speeds. Apparent discrepancies were observed between IMDC and the MC DCs overseas, while local DCs of motorcycles and LDVs follow a prevailing trend determined by the new factors of public culture and urban development. CO was the major criteria pollutant of the MCs exhaust, and formaldehyde and benzene were ranked as the first and second principal toxic gases, respectively. The air-fuel mixture control system and combustion quality of 150 and 200 cc MCs were impaired with the vehicle speed, but the same is not true for the 125 cc MCs.

How does unsustainable urbanization affect driving behavior and vehicular emissions? Evidence from Iran

Poor urban development and social instability are the results of unsustainable urbanization. These urban risks could significantly influence public culture and might even lead to aggressive driving styles. A practical approach comprising of model estimation and real-world measurements is applied here to discuss the role of urban development and public culture in the driving behavior and vehicle emissions in an unsustainable urbanized city, i.e. Isfahan, Iran. Over 60,000 speed-time data were collected from the streets for several time slices to develop the ISFahan Driving Cycle (ISFDC). ISFDC is assessed against the DCs of foreign countries and other Iranian cities to discuss the contribution of the studied factors to driving behavior. ISFDC is then entered into the IVE model to estimate the exhaust emission factors (EFs) under real-urban conditions, while IVE is primarily adjusted to the real-world experiments. Also, several emission mitigation scenarios that are likely to mitigate vehicular emissions are evaluated. Results show that ISFDC is already unique around the world, but unsustainable urbanization in terms of poor urban development and aggressive actions/reactions plays a vital role in the driving behavior of Iranian drivers. Unsustainable urbanization causes the CO and NOx EFs of Isfahan vehicles to be 40 and 25.47 % higher than those in Tehran, and 60 and 57 % higher than those in Beijing, respectively. Among the studied EFs, CO EF is more affected by the level of urban development. Ammonia, Formaldehydes, and Benzene are consecutively ranked as the major toxic gases in the Isfahan vehicle exhausts.

Emission inventory for on-road traffic fleets in Greater Yangon, Myanmar

On-road traffic emissions of Greater Yangon in 2015 were estimated using IVE model. Local surveys revealed the engine technology distributions, driving activities and flows for the fleets of bus, personal car (PC), pickup (PU), taxi, van and light duty truck. Vehicles in Greater Yangon were relatively new but recent use of leaded gasoline caused deactivation of catalytic converters that bring about high emission factors (EFs) of CO, VOC and NOx from gasoline-powered vehicles. Pre-Euro diesel-powered buses and trucks were high PM emitters while pre-Euro and Euro1 gasoline vehicles were high emitters of CO and VOC. Composite EFs of CO and VOC were the highest for PU (45.1 and 3.2 g/km, respectively) followed by taxi (34.2 and 2.6 g/km, respectively). CNG vehicles with their small number and low EFs contributed the least to total on-road traffic emissions. The bus fleet, despite being diesel-powered at only 28%, still had the highest EFs of PM and NOx, 1.6 and 2.7 g/km, respectively. Total emissions for 2015 (base case) in Greater Yangon from six surveyed fleets and the motorcycle fleet of CO; VOC; NOx; PM; BC; OC; CO2; CH4 and air toxics, in Gg/year, were 358; 41; 24; 3.8; 1.6; 0.9; 5358, 6.8 and 3.1, respectively. If all vehicles in this domain at least comply with Euro3 standard, the collective emission reduction from the base case of the air pollutants would be 71% while that of GWP (GHGs and short-lived climate pollutants) 43%, hence showing significant potential co-benefits.

Co-Benefits of Climate Change Mitigation for Public Transport in Different Cities of Vietnam

Potentiality of co-benefits for public transport at cities of different grades in Vietnam namely Ho Chi Minh city (special city), Da Nang (centrally-run grade I city) and Vinh (grade I city under the province) in 2013 was studied. Taxis in Da Nang and Vinh, and buses in Ho Chi Minh City were selected for the study. A same methodology was used for all cities. In each city, three areas and nine routes in inner city were selected for conducting this study. Information on the technical conditions of vehicles was collected by questionnaires. Traffic volume was determined by vehicle counting. The real–world driving data of vehicles were recorded by GPS technology. All collected data were processed to generate input files to run IVE model associated with base state and three proposed scenarios of climate change mitigation. Emission factors (EF) of air pollutants for these transport means were determined. Co-benefits of climate, air quality and health for the scenarios in three cities were assessed. The obtained results in this study can be used as a scientific basis for integrated air quality management in the cities in general and for air pollution control of public transport in particular.
 co-benefits, public transport, emission factor, IVE model, Vietnam.

Pyrolytic Gaseous Hydrocarbon Generation and the Kinetics of Carbon Isotope Fractionation in Representative Model Compounds With Different Chemical Structures

AbstractFive model compounds with representative chemical structures were selected for use in simulation experiments of pyrolytic gas production. The gas production and isotopic fractionation characteristics were observed and analyzed. Then, the factors affecting carbon isotope fractionation during natural gas generation were discussed, and a fractionation model was established and calibrated. We concluded that the final hydrocarbon gas (C1–5) yield of octadecane, octadecylamine, octadecanoic acid, decahydronaphthalene, and 9‐phenylanthracene decreased in turn with the effective hydrogen content. Compared with linear alkanes or alkyl compounds, cycloalkanes have higher thermal stability and generate gas later. The variation in the carbon isotopic composition of natural gas is primarily controlled by the following three factors: (a) the thermal evolution of organic matter results in a gradually heavier isotopic composition for the main gas production stage. (b) Gas inherits the isotopic composition of its parent material, and this effect is evident when the chemical structure and gas generation mechanism between parent materials are similar. (c) The structure of organic matter determines the reaction mechanism of gas generation, which has a significant influence on the range and trend of carbon isotope fractionation in the process of methane generation. An improved chemical kinetic model can accurately characterize carbon isotope fractionation during gas generation.

Emission characteristics and high-resolution spatial and temporal distribution of pollutants from motor vehicles in Chengdu, China

The establishment of the air pollutant emission inventory of urban motor vehicles is the key to control motor vehicle pollution; therefore, the purpose of this paper is to develop an air pollutant emission inventory of urban motor vehicles in Chengdu. The IVE model localization including the actual measurement correction was completed, the motor vehicle emission factors on various types of roads in Chengdu's different development areas were calculated, and the 1 km × 1 km on-road mobile source emission inventory for the year of 2016 was established in the bottom-up method based on the collected data on road network, traffic flow, vehicle driving cycle, the vehicle population in Chengdu, etc. The inventory showed that the CO, VOCs, NOx, SO2, PM10 and NH3 emissions of Chengdu's on-road mobile sources had reached 432.2 kt, 44.8 kt, 72.4 kt, 0.4 kt, 11.3 kt and 6.2 kt respectively in 2016. Light-duty vehicle, medium-duty vehicle, and heavy-duty vehicle were the major contributors to CO emissions, and their CO emissions accounted for 44%, 14% and 11% of the total CO emission respectively; VOCs mainly came from light-duty vehicle, motorcycle, and heavy-duty truck, the VOCs emissions of which accounted for 49%, 19% and 10% of the total VOCs emission respectively; NOx and SO2 mainly came from light-duty vehicle and heavy-duty truck, the NOx emissions of which accounted for 25% and 48% of the total NOx emission, and the SO2 emissions of which accounted for 70% and 14% of the total SO2 emission respectively; in addition, the heavy-duty truck caused PM10 emission accounting for 78% of the total PM10 emission, while the light-duty vehicle caused NH3 emission accounting for 81% of the total NH3 emission. The spatial distribution of on-road mobile source pollutant emissions showed that emissions were concentrated in the downtown with a decreasing trend from the downtown to the suburbs and the outer suburbs. Based on the 95% confidence intervals, the uncertainties of CO, VOCs and NOx emission estimations were relatively low with relative errors ranging from - 68% to 87%, 58%–84% and 97%–75%. Considering the uncertainties of the traffic flows and emission factors, the on-road mobile source emission inventory shall be further improved to provide important scientific research supporting for the prevention and control of air pollution in Chengdu.

Vehicle Emission Computation Through Microscopic Traffic Simulation Calibrated Using Genetic Algorithm

Abstract Vehicle emission calculation is critical for evaluating motor vehicle related environmental protection policies. Currently, many studies calculate vehicle emissions from integrating the microscopic traffic simulation model and the vehicle emission model. However, conventionally vehicle emission models are presented as a stand-alone software, requiring a laborious processing of the simulated second-by-second vehicle activity data. This is inefficient, in particular, when multiple runs of vehicle emission calculations are needed. Therefore, an integrated vehicle emission computation system is proposed around a microscopic traffic simulation model. In doing so, the relational database technique is used to store the simulated traffic activity data, and these data are used in emission computation through a built-in emission computation module developed based on the IVE model. In order to ensure the validity of the simulated vehicle activity data, the simulation model is calibrated using the genetic algorithm. The proposed system was implemented for a central urban region of Nanjing city. Hourly vehicle emissions of three types of vehicles were computed using the proposed system for the afternoon peak period, and the results were compared with those computed directly from the IVE software with a trivial difference in the results from the proposed system and the IVE software, indicating the validity of the proposed system. In addition, it was found for the study region that passenger cars are critical for controlling CO, buses are critical for controlling CO and VOC, and trucks are critical for controlling NOx and CO2. Future work is to test the proposed system in more traffic management and control strategies, and more vehicle emission models are to be incorporated in the system.

HEALTH CO-BENEFITS OF CLIMATE CHANGE MITIGATION FOR THE BUS SYSTEM OF HANOI

The real–world driving data of the five bus routes of Hanoi, namely No. 9, 18, 25, 32 and 33, were collected using a GPS with the update rate of 1 Hz. GPS data were processed and used to simulate the emission by IVE model for the base state and three scenarios of air pollution control of Hanoi bus system. Co-benefits of climate, air quality and health were deternined. The obtained results show that either the fuel switching or the tightening of emission standards bring significant benefits of environment and health.

THE DETERMINATION OF DRIVING CHARACTERISTICS OF HANOI BUS SYSTEM AND THEIR IMPACTS ON THE EMISSION

A GPS with the update rate of 1 Hz was used to collect the real–world driving data of the five bus routes of Hanoi, namely No. 9, 18, 25, 32 and 33, on weekdays and weekends. GPS data were processed and used to simulate the emission by IVE model. The driving characteristics of Hanoi bus system and their impacts on the emission were determined. Results obtained shown that the real –world driving characteristics are different from area to area and affect the emissions of vehicles. This paper, therefore, reconfirms the necessarity of the development of the typical driving cycle before conducting the emission inventory for mobile sources.

Development of Air Toxic Emission Factor and Inventory of On-road Mobile Sources

Dynamic emission factors of air toxic compounds, emitted from vehicles in Bangkok, Thailand, are developed using the IVE model. The model takes into account the actual fleet and characteristics of vehicles in the study area. It is found that the calculated emission factors are greatly influenced by vehicle emission control policy. Approximately 2000 tons of benzene emission per year is reduced by the changing of fuel quality from Euro 2 to Euro 4 standards. As for mitigation measures, introduction of gasohol and natural gas as alternative fuels, as well as encouraging the utilization of public transportation systems, are analyzed. The outcomes reveal that a combined scenario using 100% gasohol plus decreasing vehicle kilometers traveled (VKT) by 20% is the most effective in reduction of benzene emission. In addition, 1,3-butadiene, acetaldehyde and formaldehyde emissions are greatly decreased by the combined scenario of using compressed natural gas (CNG) plus decreasing VKT by 20%.

NOx emissions from Euro IV busses with SCR systems associated with urban, suburban and freeway driving patterns

NOx and particulate matter (PM) emissions from heavy-duty diesel vehicles (HDVs) have become the most important sources of pollutants affecting urban air quality in China. In recent years, a series of emission control strategies and diesel engine polices have been introduced that require advanced emission control technology. China and Europe mostly have used Selective Catalytic Reduction (SCR) with urea to meet the Euro IV diesel engine emission standard. In this study, two Euro IV busses with SCR were tested by using potable emission measurement system (PEMS) to assess NOx emissions associated with urban, suburban and freeway driving patterns. The results indicated that with the SCR system, the urea injection time for the entire driving period increased with higher vehicle speed. For freeway driving, the urea injection time covered 71%–83% of the driving period; the NOx emission factors from freeway driving were lower than those associated with urban and suburban driving. Unfortunately, the NOx emission factors were 2.6–2.8-, 2.3–2.7- and 2.2–2.3-fold higher than the Euro IV standard limits for urban, suburban and freeway driving, respectively; NOx emission factors (in g/km and g/(kW·h)) from the original vehicles (without SCR) were higher than their corresponding vehicles with SCR for suburban and freeway driving. Compared with the IVE model results, the measured NOx emission factors were 1.60–1.16-, 1.77–1.27-, 2.49–2.44-fold higher than the NOx predicted by the IVE model for urban and suburban driving, respectively. Thus, an adjustment of emission factors is needed to improve the estimation of Euro IV vehicle emissions in China.

Research for NO<sub>x</sub> Emission of Nanjing Vehicle Based on IVE Model

This paper researched on vehicles’ emissions in Nanjing based on IVE model and presented the method to quantify the main inputting parameters of IVE model. This research has collected the traffic of different types of roads in Nanjing. The light-duty vehicles, taxis, buses and trucks respectively accounted for 73.4%, 13.3%, 10.3% and 3.0% of the total traffic volume. According to vehicle driving condition data collected by GPS, the driving cycle of light-duty vehicles in Nanjing was defined. The on-road vehicles’ emission data were measured using the on-board vehicle emission analyzer made by ourselves. Then the correction factors of NOx in IVE model could be obtained using the testing emission data. The results of IVE model showed that the daily NOx emission of light-duty vehicles, taxis, buses and trucks in Nanjing city were 17.79t, 5.51t, 146.37t and 83.78t. Buses and trucks were the main emission sources of NOx, with the contribution of 57.75% and 33.06%.

Estimation of automobile emissions and control strategies in India

Rapid, but unplanned urban development and the consequent urban sprawl coupled with economic growth have aggravated auto dependency in India over the last two decades. This has resulted in congestion and pollution in cities. The central and state governments have taken many ameliorative measures to reduce vehicular emissions. However, evolution of scientific methods for emission inventory is crucial. Therefore, an attempt has been made to estimate the emissions (running and start) from on-road vehicles in Chennai using IVE model in this paper. GPS was used to collect driving patterns.The estimated emissions from motor vehicles in Chennai in 2005 were 431, 119, 46, 7, 4575, 29, and 0.41tons/days respectively for CO, VOC, NOx, PM, CO2, CH4 and N2O. It is observed from the results that air quality in Chennai has degraded. The estimation revealed that two and three-wheelers emitted about 64% of the total CO emissions and heavy-duty vehicles accounted for more than 60% and 36% of the NOx and PM emissions respectively. About 19% of total emissions were that of start emissions. It is also estimated that on-road transport contributes about 6637tons/day CO2 equivalent in Chennai. This paper has further examined various mitigation options to reduce vehicular emissions. The study has concluded that advanced vehicular technology and augmentation of public transit would have significant impact on reducing vehicular emissions.

Purchasing Power Parity in the Long Run: A Test of the Dollar/Pound Exchange Rate (1890-1978)

This paper tests the Purchasing Power Parity (PPP) hypothesis by analyzing t he long-run tendency of the dollar/pound exchange rate using data sin ce 1890. Two different models are considered: (1) a na ive model and (2) a modified monetary model. The conditions of propor tionality and symmetry cannot be rejected when using the naive model. The final results using the monetary model, however, indicate that t he existence of permanent deviations from PPP cannot be ruled out. Copyright 1987 by Ohio State University Press.

Chemistry of Interstitial Waters of Marine Sediments

In recen t years muc h in terest has developed in the processes that have l ed to the present chemical composi tion of the oceans. A mong the pioneering efforts were those o f Gol dschm idt 1933) and Conway 1943). These authors made up approxi­ mate mass balances and calculated the amounts of primary rocks that mus t have weathered to account for the chemical composition of the o cean and the sediments. This work was l ater amplified by Horn & A dams 1966). In the m ass bal ances considered by these various authors, no ser ious attention was given to the possible recycling of materials, nor to the o cean as just one geochemical reservoir through which the elemen ts pass on to a subsequ ent reservoir, namely the s ediments . Considerat ions of t his type were introduced by Barth (1952) and Gol dber g & Arrhenius 1958). The latter authors found good agreemen t between measured rates o f i nput o f some element s into the o cean, vi a the ri vers and the atmosphere, and the ratc of output into thc s edimcn ts. Such balanccs suggest that a stcady state exists in the overall geochemical cycle. In a different approach Sil len ( 967) used a simple chemical equi l ibrium model to account for the composition of sea water. He assumed an e quil ibrium between the ocean an d the m arine sediments, part icul arly w ith the alumino-sil icate and the carbonate phases. Broecker (1971) cri ticized this model , especially because i t tends to discourage any i nquiry into the reactions that m ay t ake place in the various geochemical reservoirs. Broeck er specifical ly ci tes examples that could impl y variatio ns in the i onic compositi on of sea water wi th time, an d he advocates a kinetic approach to the problem, which wou ld then l ead to a search for the processes that control the apparent s teady s tate as i t exists today. Garrels & Mackenzie (1971) developed a steady-state model based on the concept of chemical uniformi tarianism, in w hich the to tal mass and the chemical com­ pos ition of s edimen tary rocks, as well as the c h emical compos ition of the depos ited materials , have remained constan t wi th time, that is, at l east during the las t two b il l ion years. These authors (Garrel s & M ackenzie 1972, Garrels & Perry 1974) have developed this concept i nt o a quantitat ive model i nvolvi ng both estimates of overall fluxes and residen ce times of chemi cal el ements in various geochemical

Regge pole-cut effective trajectories and the dual absorptive model

Recent ly IIARARI has proposed an in teres t ing dual absorpt ive model for two-body hadronic ampl i tudes , incorpora t ing good features of both the convent ional Regge models and opt ical or absorp t ive models (x.2). I t explains qua l i ta t ive ly a number of features of high-energy scat ter ing like the cross-over phenomena, the presence or the absence of ]t] ~ (0 :6) (GeV) 2 dips in elast ic and inelastic sca t ter ing and cer ta in facts about the polar izat ions and par t ic le-ant ipar t ic le cross-sections. Some quan t i t a t i ve success in fitt ing K+p, K p elast ic differential cross-sections at P,,b = 5 GeV/c for It[ < ~ 1.5 (GeV) ~ has been also achieved (2). The main assumption of I ta rar i ' s model is t ha t the imaginary par t of the nonpomeron ampl i tude {including Regge poles, cuts, etc.) is domina ted by the most per ipheral par t ia l waves within the interact ion radius r. The pome. ron par t , which is supposed to be connected to the nonrcsonant background, is then added to this contr ibut ion. Then, apar t f rom the pomeron contr ibut ion to the hcl iei ty nonflip ampli tudes , the imaginary par t s of the s-channel hel ici ty ampl i tudes are given by