Feasibility of hydrogen fuel cell technology for railway intercity services:a case study for the Piedmont in North Carolina

Diesel fuel combustion results in exhaust containing air pollutants and greenhouse gas emissions.Many railway vehicles use diesel fuel as their energy source.Exhaust emissions,as well as concerns about economical,alternative power supply,have driven efforts to move to hydrogen motive power.Hydrogen fuel cell technology applied to railways offers the opportunity to eliminate harmful exhaust emissions and the potential for a low-or zero-emission energy supply chain.Currently,only multiple-unit trains with hydrail technology operate commercially.Development of an Integrated Hybrid Train Simulator for intercity railway is presented.The proposed tool incorporates the effect of powertrain components during the wheel-to-tank process.Compared to its predecessors,the proposed reconfigurable tool provides high fidelity with medium requirements and minimum computation time.Single train simulation and the federal government’s Greenhouse gases,Regulated Emissions,and Energy use in Transportation(GREET)model are used in combination to evaluate the feasibility of various train and powertrain configurations.The Piedmont intercity service operating in North Carolina is used as a case study.The study includes six train configurations and powertrain options as well as nine hydrogen supply options in addition to the diesel supply.The results show that a hydrail option is not only feasible,but a low-or zero-carbon hydrogen supply chain could be possible.

Criteria air pollutants and hospitalizations of a wide spectrum of cardiovascular diseases: A nationwide case-crossover study in China

Few national studies have systemically examined the effects of criteria air pollutants on cardiovascular morbidity.This study aimed to investigate the associations between all criteria air pollutants and hospitalization of causespecific cardiovascular diseases(CVD)in China.We obtained data on CVD hospitalization events of four major categories and 12 specific diseases from 153 hospitals distributed in 20 provincial-level regions from 2013 to 2020.We adopted a time-stratified case-crossover study design using individual cases to capture the effect of short-term exposure to six criteria air pollutants on CVD hospitalizations,using conditional logistic regression models.More than 1.1 million CVD hospitalization events were included.The lag pattern exploration demonstrated the largest effect for six air pollutants on lag 0–1 day.PM_(2.5),PM_(10),NO_(2),and CO were significantly associated with increased hospitalization from ischemic heart diseases,cerebrovascular diseases,other heart diseases,and five specific causes of CVD.The effect estimates of NO_(2)were the most robust when adjusting for copollutants.The concentration-response curves were positive and linear for most pollutant–endpoint pairs(except for O_(3)),and these positive associations remained even below the 24-h levels recommended by WHO Air Quality Guidelines and China Air Quality Standards.This nationwide case-crossover study in China demonstrated that short-term exposure to multiple ambient air pollutants may significantly increase the risk of cause-specific CVD hospitalizations even under the most stringent air quality regulations,striking an alert for potential CVD patients against these environmental risk factors.

Non-point source analysis of a railway bridge area using statistical method:Case study of a concrete road-bed

In an effort to protect the quality of the water system, interest in non-point source pollution is increasing. Recently, studies of non-point sources pollution are continuing in relation to various land- use areas, but such studies have not been fully conducted in railway facility sites. Using monitoring data of railway bridge area with concrete road-bed, the runoff characteristics, pollutant unit loads, and first flush criteria were assessed. Railway bridge area with concrete road-bed typically show the first flush effect, and the pollutant unit load was determined to be higher than other public facilities areas. Further, the first flush criteria show an effective rainfall amount of 7 mm. In other words, from the runoff of railway facilities, considerable amounts of non-point source pollutants are occurred, indicating the need to create best management practices which are adequate for railway facility sites.