Driver training interests of a Spanish sample of young drivers and its relationship with their self-assessment skills concerning risky driving behavior

Poor driving self-assessment skills (e.g., over-confidence) have been pointed out as an important explanatory factor behind young drivers’ accident involvement. This paper explores (1) what young drivers miss in their training as drivers in order to analyze whether an assessment of one's own driving skills plays an important role in their desire to improve as drivers, and (2) how these training interests are related to an estimate of their self-assessment skills concerning risky driving behavior. For this purpose, a study was conducted using a survey with a blocked sampling design of novice drivers. The survey solicited respondents’ self-report about (1) the contents of training courses that they feel would improve their driving, (2) their risky driving behavior, and (3) their likelihood of being involved in a risky driving situation. From the initial sample invited to participate, of nearly 1300 people, we finally obtained complete data from 321 young Spanish drivers. Two main results were apparent from our data analysis: (1) the novice drivers were mainly interested in improving their ability to recognize their strengths and weaknesses as drivers (i.e., self-assessment skills); (2) a significant relationship was found between novice drivers’ interests and their current self-assessment skills concerning risky driving behavior. Specifically, there was greater general interest expressed in post-license training by the under-confident self-assessors than the over-confident ones. These results provide a relevant input which should be taken into account when designing driver training programs for novice drivers. Moreover, the relationship between their training interests and their risky driving self-assessment skills introduces an additional factor to be considered in the implementation of these training programs.     

Performance evaluation of the HR-ELPI + inversion

Data inversion methods used in aerosol measurement instruments have significant influence on the resolution and quality of the result. A freshly launched new electrical low pressure impactor (ELPI) instrument version, high resolution ELPI+ (HR-ELPI+, Dekati Ltd.), uses an iterative inversion calculation method to improve particle size resolution, concentration, and data analysis quality. In this article, the performance of the HR-ELPI?+?is critically analyzed by simulations and experiments in laboratory and field conditions, and the results are compared with a conventional inversion data analysis method (cut-point diameter concept) and with common reference instruments (e.g., SMPS and EEPS). The results showed that the HR-ELPI?+?inversion has limited performance at the lower and upper limits of the instrument’s size range, and can suffer if the raw currents have signal dependent noise more than 50% or electric noise more than 1%. However, the HR-ELPI?+?clearly provide remarkably better resolution and quality with low oscillation risk compared to the conventional cut-point diameter concept of the ELPI. The HR-ELPI?+?also showed generally very similar size distributions and number concentrations compared to the reference instruments.

© 2018 American Association for Aerosol Research     

Sampling Conditions for the Measurement of Nucleation Mode Particles in the Exhaust of a Diesel Vehicle

A novel porous tube diluter was characterized to define sampling parameters for repeatable measurements of nucleation-mode particles (NMPs) in the exhaust of a modern diesel passenger car at moderate engine load. This porous tube diluter permits the variation of sampling parameters independently and in a wide range. We investigated the sampling parameters: primary dilution temperature (PDT; 15–55°C), primary dilution ratio (PDR; 8–45), residence time (RT; 0.5–4.0 s), and relative humidity of primary dilution (PRH; 5–90%). Decreased PDT and increased PRH led to a growth of particle number and size in the nucleation mode. While a maximum number of NMPs was found at moderate PDRs between 20 and 30, a maximum volume of NMPs was achieved at PDRs below 20. Coagulation explains the number reduction of NMPs under sampling conditions of prolonged RT and decreased PDR. However, the size growth of the nucleation mode can only partly be attributed to coagulation, and thus growth due to organic compounds from the exhaust probably plays an important role. Sensitivity analysis was conducted as a function of PDR-PDT and revealed two optimal sampling conditions for repeatable NMPs in number or repeatable maximum NMPs in volume. In addition to the sampling parameters, exhaust line conditioning was found to affect NMPs strongly and thus needs to be controlled to minimize effects on the history of measurements.     

Mass Measurement of Non-Spherical Particles: TDMA-ELPI Setup and Performance Tests

An ELPI was introduced to the TDMA setup for measurement of effective density and particle mass. This allows measurement of particle mass change also in cases when the particles are non-spherical or have voids. In addition to mass change of a particle, the density of transferred matter can be calculated if either unconditioned or conditioned particles are spherical and the bulk (material) density of the core particle is known. The performance of the system was tested by numerical simulations and laboratory experiments. According to the results, the smallest detectable particle mass change is approximately ± 17%. The measured density for the condensing species was within 15% of the bulk density value. Particle mass change caused by condensation of semi-volatile components of exhaust gas on diesel soot particles was also demonstrated.     

Symmetric and asymmetric impacts of the palm oil industry on carbon dioxide emissions in Malaysia based on linear and nonlinear autoregressive distributed lag models

Clean Technologies and Environmental Policy - Palm oil is a major global commodity that is vital for the well-being of many communities. Despite its significant contribution to the attainment of...     

Modification of the ELPI to measure mean particle effective density in real-time

A new modification of electrical low pressure impactor (ELPI) for the particle effective density measurement is presented. The system is capable of real-time operation and it is based on the serial measurement of mobility and aerodynamic diameter. In the studied configuration, a zeroth order mobility analyser is installed inside of the ELPI-instrument. The system is feasible for single modal distributions. For several particle materials and varying size distributions, the measured average density values were within 15% of the values obtained with a reference method.     

Comparison of the Properties of TiC/Fe-AI Composites Produced by Self-Propagating High-Temperature Synthesis and Hot Isostatic Pressing

Self-propagating high-temperature synthesis (SHS) and hot isostatic pressing (HIP) techniques were used to produce TiC-20 wt.% Fe-Al and TiC-40 wt.% Fe-Al composite materials. The microstructure of the materials produced by the SHS technique consisted of spherical carbide particles embedded in an iron aluminide matrix whereas the microstructure of the materials produced by the HIP technique was less regular. A maximum hardness of 1820 HV was measured for the material produced using HIP and a maximum fracture toughness of 16.3 MPa ^1/2 was obtained for the material produced by SHS. Hardness values obtained from samples produced by the HIP technique were higher than those obtained from samples produced by the SHS technique. The SHS samples had better fracture toughness. The results of the oxidation resistance tests showed that TiC/Fe-Al composite materials can be recommended for use in oxidative environments holding temperatures up to 800^°C.     

Performance of Two Fluorescence-Based Real-Time Bioaerosol Detectors: BioScout vs. UVAPS

A 405 nm diode laser-based on-line bioaerosol detector, BioScout, was tested and compared with the Ultraviolet Aerodynamic Particle Sizer (UVAPS). Both instruments are based on laser-induced fluorescence of particles. Only a fraction of microbial particles produce enough fluorescence light to be detected by the instruments. This fluorescent particle fraction (FPF) is aerosol and instrument specific. The FPF values for common bacterial and fungal spores and biochemical particles were experimentally determined for both instruments. The BioScout exhibited higher FPF values for all the test aerosols except coenzyme NADH. The difference was higher for smaller particles. The FPF values of fungal spores and bacteria varied between 0.34 to 0.77 and 0.13 to 0.54 for the BioScout and the UVAPS, respectively. The results indicate that the 405 nm diode laser is a useful excitation source for fluorescence-based real-time detection of microbial aerosols. The FPF results of this study can be utilized to estimate the actual concentrations of bacterial and fungal spores in fluorescence-based ambient measurements.

Copyright 2014 American Association for Aerosol Research     

Modelling of a side reactor configuration combining reaction and distillation

A new software tool to simulate and optimise processes that combine distillation column with a reactor sequence has been developed. This kind of combination is particularly interesting when new intensified and integrated processes are developed. The unit block contains both the distillation column model and the models for the coupled reactors. The model equations are solved simultaneously in one block and not sequentially as it is done when the reactor/distillation systems are solved by present flowsheet programs. This software module has been implemented into a flowsheet simulator environment that contains all required physical and chemical data banks and enables large-scale process optimisation. The applicability of the new module is demonstrated by solving two presently interesting processes: production of MTBE and isooctene. The model has shown good convergence properties.