Estimating impacts of emission specific characteristics on vehicle operation for quantifying air pollutant emissions and energy use

This paper proposes and illustrates a methodology to predict the fraction of time motor vehicles spend in different operating conditions from readily observable variables called emission specific characteristics （ESC）. ESC describe salient characteristics of vehicles, roadway geometry, the roadside environment, traffic, and driving style （aggressive, normal, and calm）. The information generated by our methodology can then be entered in vehicular emission models that rely on vehicle specific power, i.e., comprehensive modal emissions model （CMEM）, international vehicle emissions （IVE）, or motor vehicle emission simulator （MOVES） to compute energy consumption and vehicular emissions for various air pollutants. After generating second-by-second vehicle trajectories from a calibrated micro-simulation model, the authors estimated structural equation models to examine the influence of link ESC on vehicle operation. Authors＇ results show that 67% of the link speed variance is explained by ESC. Overall, the roadway geometry exerts a greater influence on link speed than traffic characteristics, the roadside environment, and driving style. Moreover, the speed limit has the strongest influence on vehicle operation, followed by facility type and driving style. Better understanding the impact on vehicle operation of ESC could help metropolitan planning organizations （MPOs） and regional transportation au- thorities predict vehicle operations and reduce the environmental footprint of motor vehicles.

Suggestion on further strengthening ultra-low emission standards for PM emission from coal-fired power plants in China

China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs)to achieve ultra-low emission.The potential for further particulate matter(PM)emission reduction to achieve near-zero emission for CFPPs has become a hotspot issue.In this study,PM emission from some ultra-low emission CFPPs adopting advanced air pollutant control technologies in China was reviewed.The results revealed that the average filterable particulate matter(FPM)concentration,measured as the total particulate matter(TPM)according to the current national monitoring standard,was(1.67±0.86)mg/m^(3),which could fully achieve the ultra-low emission standard for key regions(5 mg/m^(3)),but that achieving the near-zero emission standard was difficult(1 mg/m^(3)).However,the condensable particulate matter(CPM),with an average concentration of(1.06±1.28)mg/m^(3),was generally ignored during monitoring,which led to about 38.7%underestimation of the TPM.Even considering both FPM and CPM,the TPM emission from current CFPPs would contribute to less than 5%of atmospheric PM_(2.5) concentrations in the key cities and regions in China.Therefore,further reduction in FPM emission proposed by the near-zero emission plan of CFPPs may have less environmental benefit than emission control of other anthropogenic sources.However,it is suggested that the management of CPM emission should be strengthened,and a national standard for CPM emission monitoring based on the indirect dilution method should be established for CFPPs.Those measurements are helpful for optimal operation of air pollutant control devices and continuously promoting further emission reduction.

Detection and Local Staging of Prostate Cancer by 68Ga-PSMA-PET/CT, Comparison with mpMRI and Histopathology

Introduction: 68Ga-PSMA-PET/CT has proven its value in prostate cancer with high positive predictive value for lymph node metastasis and superior detection of distant metastasis. There is growing evidence that 68Ga-PSMA- PET/CT has high sensitivity for detection of tumor lesions in the prostate as well. Studies thus far have mainly been performed in patients prior to prostatectomy. Aim of this study is to evaluate diagnostic accuracy in a mixed population of men with increased risk of prostate cancer and evaluate diagnostic possibilities with respect to extra-capsular extension and seminal vesicle invasion. Methods: The population consisted of a retrospectively included sequential cohort of 69 patients with 68Ga-PSMA-PET/CT and mpMRI available. 68Ga-PSMA-PET/CT was re-evaluated by two readers blinded for mpMRI and clinical information. Likelihood of tumour presence, extra-prostatic extension and seminal vesicle invasion was scored on 5-point Likert scale and localized schematically. Results were compared with mpMRI. Available pathological outcome served as gold standard. SUVmax of index lesions was measured and correlated to index tumor Gleason grade. Results: Clinically significant prostate cancer (Gleason ≥ 3 + 4) was detected in 57 (83%) of 69 patients. Diagnostic accuracy was 89% for PET reader 1, 93% for PET reader 2 and 86% for mpMRI. Lesion concordance of 68Ga-PSMA-PET/CT and mpMRI was 97%. SUVmax of the index lesion correlated to Gleason grade. Sensitivity for extracapsular extension in the prostatectomy group was 62% for PET reader 1, 33% for PET reader 2 and 50% for mpMRI. Specificity was 62% for PET reader 1, 100% for PET reader 2 and 69% for mpMRI. Conclusion: Ga68-PSMA-PET shows high accuracy in the detection of tumor lesions in the prostate. Results on evaluating extra-capsular extension and seminal vesicle invasion are comparable to mpMRI. This study adds to the increasing evidence that 68Ga-PSMA-PET/CT is imperative in detection of prostate cancer prior to biopsy.