Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Variation of Atmospheric Pressure

Variation of Atmospheric Pressure

Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...

Factors Affecting Respiration

Factors Affecting Respiration

Respiration is a crucial physiological function involving exchanging oxygen (O2) and carbon dioxide (CO2) between an organism and its environment. Various factors can impact this essential process:

Global Climate Change

Global Climate Change

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.

Pressure and Volume in an Adiabatic Process

Pressure and Volume in an Adiabatic Process

Free expansion of a gas is an adiabatic process. However, there are few differences between free expansion and adiabatic expansion. During free expansion, no work is done, and there is no change in internal energy. But, for an adiabatic expansion, work is done, and there is a change in internal energy. During an adiabatic process, the relation between the pressure and volume is obtained from the condition for the adiabatic process, that is,

$Influence of Earth's Curvature and Atmospheric Refraction on Leveling$ 01:26

Influence of Earth's Curvature and Atmospheric Refraction on Leveling

During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance.

Radiation: Applications

Radiation: Applications

The average temperature of Earth is the subject of much current discussion. Earth is in radiative contact with both the Sun and dark space; it receives almost all its energy from the radiation of the Sun and reflects some of it into outer space. Dark space is very cold, about 3 K, so Earth radiates energy into it. For instance, heat transfer occurs from soil and grasses, the rate of which can be so rapid that frost can occur on clear summer evenings, even in warm latitudes.
The average...

Search research articles

Home
Comparison Of Vehicular Emissions At Different Altitudes: Characteristics And Policy Implications.

Home
Comparison Of Vehicular Emissions At Different Altitudes: Characteristics And Policy Implications.

Related Experiment Video

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

Published on: December 4, 2016

Comparison of vehicular emissions at different altitudes: Characteristics and policy implications.

Zhiwen Jiang¹, Haomiao Niu¹, Zhenyu Jia¹

¹Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.

Environmental Pollution (Barking, Essex : 1987)

|January 12, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

This study used real-world driving emissions data and machine learning to analyze vehicle emissions in high-altitude cities. Findings show altitude impacts CO₂ and particulate emissions, necessitating tailored reduction strategies like speed guidance.

Keywords:

High altitude Particulate number Real driving emission Vehicle emission modeling

More Related Videos

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

Published on: May 22, 2020

Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street

Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street

Published on: January 20, 2023

Related Experiment Videos

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

Published on: December 4, 2016

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

Measuring Sub-23 Nanometer Real Driving Particle Number Emissions Using the Portable DownToTen Sampling System

Published on: May 22, 2020

Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street

Evaluating the Effect of Roadside Parking on a Dual-Direction Urban Street

Published on: January 20, 2023

Area of Science:

Environmental Science
Automotive Engineering
Machine Learning Applications

Background:

Vehicular emissions significantly impact urban air quality and climate change.
Altitude affects vehicle performance and emissions due to changes in air pressure and density.
Understanding emission variations across different geographical and environmental conditions is crucial for effective policy-making.

Purpose of the Study:

To investigate vehicular emission characteristics in two Chinese cities at different altitudes (Tianjin and Xining) using real-world driving emissions (RDE) data.
To identify key factors influencing emissions, including altitude, driving conditions, and emission standards.
To evaluate the effectiveness of emission reduction strategies, such as speed guidance and emission standard upgrades.

Main Methods:

Utilized machine learning algorithms to analyze RDE data collected from vehicles in Tianjin and Xining.
Compared emission data (CO₂ and particulate number - PN) between the two cities, considering altitude differences.
Quantitatively assessed the impact of speed guidance and emission standard upgrades on reducing specific pollutants.

Main Results:

Significant differences in CO₂ and particulate number (PN) emissions were observed between Tianjin and Xining, attributed to altitude-induced air pressure variations.
Road grade and air pressure were identified as critical factors influencing emissions in high-altitude environments.
Speed guidance demonstrated a substantial reduction in PN emissions (34.8%) in high-altitude areas.
Upgrading emission standards led to a consistent reduction in CO₂ emissions (6.1%) across both locations.

Conclusions:

Altitude-induced changes in air pressure and their effects on combustion efficiency and air resistance are significant drivers of vehicular emission variations.
Tailored emission control strategies are necessary, considering local environmental factors and altitude.
Implementing speed guidance in high-altitude regions and upgrading emission standards are effective measures for reducing vehicular pollution.