68 research outputs found
Evidence-based nanoscopic and molecular framework for excipient functionality in compressed orally disintegrating tablets
The work investigates the adhesive/cohesive molecular and physical interactions together with nanoscopic features of commonly used orally disintegrating tablet (ODT) excipients microcrystalline cellulose (MCC) and D-mannitol. This helps to elucidate the underlying physico-chemical and mechanical mechanisms responsible for powder densification and optimum product functionality. Atomic force microscopy (AFM) contact mode analysis was performed to measure nano-adhesion forces and surface energies between excipient-drug particles (6-10 different particles per each pair). Moreover, surface topography images (100 nm2-10 μm2) and roughness data were acquired from AFM tapping mode. AFM data were related to ODT macro/microscopic properties obtained from SEM, FTIR, XRD, thermal analysis using DSC and TGA, disintegration testing, Heckel and tabletability profiles. The study results showed a good association between the adhesive molecular and physical forces of paired particles and the resultant densification mechanisms responsible for mechanical strength of tablets. MCC micro roughness was 3 times that of D-mannitol which explains the high hardness of MCC ODTs due to mechanical interlocking. Hydrogen bonding between MCC particles could not be established from both AFM and FTIR solid state investigation. On the contrary, D-mannitol produced fragile ODTs due to fragmentation of surface crystallites during compression attained from its weak crystal structure. Furthermore, AFM analysis has shown the presence of extensive micro fibril structures inhabiting nano pores which further supports the use of MCC as a disintegrant. Overall, excipients (and model drugs) showed mechanistic behaviour on the nano/micro scale that could be related to the functionality of materials on the macro scale. © 2014 Al-khattawi et al
One-step synthesis of a silicon/hematite@carbon hybrid nanosheet/silicon sandwich-like composite as an anode material for Li-ion batteries
Ru@Carbon Nanotube Composite Microsponge: Fabrication in Supercritical CO2 for Hydrogenation of p-Chloronitrobenzene
Novel heterogeneous catalysts are needed to selectively anchor metal nanoparticles (NPs) into the internal space of carbon nanotubes (CNTs). Here, supercritical CO2 (SC-CO2) was used to fabricate the Ru@CNT composite microsponge via impregnation. Under SC-CO2 conditions, the highly dispersive Ru NPs, with a uniform diameter of 3 nm, were anchored exclusively into the internal space of CNTs. The CNTs are assembled into a microsponge composite. The supercritical temperature for catalyst preparation, catalytic hydrogenation temperature, and time all have a significant impact on the catalytic activity of Ru@CNTs. The best catalytic activity was obtained at 100 °C and 8.0 MPa: this gave excellent selectivity in the hydrogenation of p-chloronitrobenzene at 100 °C. This assembly strategy assisted by SC-CO2 will be promising for the fabrication of advanced carbon composite powder materials
Application of Natural Language in Fire Spread Display
How to express fire spread efficiently and effectively to firefighters was an important issue. The present study aimed to investigate how to present the fire alarm information, focusing on whether natural language alarm presentation was better than the alarm list presentation. Objective method and subjective evaluation were used to compare the difference among different expressions. The results revealed that natural language was better than alarm list in described a fire spread situation, and the effect was more robust when spatial information was added. Traditional alarm list was more accuracy than other forms, but it cost more time to read and comprehension. So natural language with spatial information will be recommended to the future design of fire alarm system.</p
Near-Zero Thermal Expansion and Phase Transitions in HfMg1−xZnxMo3O12
The effects of Zn2+ incorporation on the phase formation, thermal expansion, phase transition, and vibrational properties of HfMg1−xZnxMo3O12 are investigated by XRD, dilatometry, and Raman spectroscopy. The results show that (i) single phase formation is only possible for x ≤ 0.5, otherwise, additional phases of HfMo2O8 and ZnMoO4 appear; (ii) The phase transition temperature from monoclinic to orthorhombic structure of the single phase HfMg1−xZnxMo3O12 can be well-tailored, which increases with the content of Zn2+; (iii) The incorporation of Zn2+ leads to an pronounced reduction in the positive expansion of the b-axis and an enhanced negative thermal expansion (NTE) in the c-axes, leading to a near-zero thermal expansion (ZTE) property with lower anisotropy over a wide temperature range; (iv) Replacement of Mg2+ by Zn2+ weakens the Mo–O bonds as revealed by obvious red shifts of all the Mo–O stretching modes with increasing the content of Zn2+ and improves the sintering performance of the samples which is observed by SEM. The mechanisms of the negative and near-ZTE are discussed
Negativity Bias in Dangerous Drivers
The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs) revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes.</p
Development and validation of a questionnaire to assess public receptivity toward autonomous vehicles and its relation with the traffic safety climate in China
The advent of autonomous vehicles (AVs) has gained increasing attention in China. Although auto manufacturers and innovators have attempted to confirm that AVs are safe and have introduced them on public roads, it is vital to understand end-users' acceptance of AVs. A total of 1453 participants voluntarily and validly completed a series of questionnaires. The questionnaires included the Autonomous Vehicle Acceptability Scale (AVAS), the Traffic Climate Scale (TCS), and sociodemographic variables. The satisfactory internal consistency reliability and construct validity revealed that the newly developed Chinese version of the AVAS is a suitable tool to measure public acceptance of AVs. Moreover, exploratory factor analysis and confirmatory factor analysis conformed to the four factors of AVAS, including benefits in usefulness (BIU), benefits in situations (BIS), concern scenarios (CS) and system concern (SC). Scores higher on benefits and lower on concerns represent more acceptance of AVs. In addition, we found that the public's perceived local traffic safety climate affected the attitude toward AVs. More specifically, external affective demands (EAD) were found to be a significant predictor of SC, internal requirements (IR) were shown to have an effect on BIS and CS, and functionality was found to be a significant predictor of BIU and SC. Furthermore, the differences between drivers and non-drivers revealed that drivers were concerned significantly less about AVs and regarded AVs as more useful than non-drivers did. To gain more customers for the purchase of AVs, it is necessary for automotive vehicle manufacturers and retailers to introduce and advertise the functions and usability of autonomous driving systems to the public. Gaining acceptance from end users and understanding the factors that affect acceptability will be critical to the widespread deployment of AVs
Why people like using bikesharing: Factors influencing bikeshare use in a Chinese sample
Bikesharing refers to a short-term bicycle rental service for pedestrians provided by enterprises or the government. The aim of this study was to evaluate the public attitude toward bikesharing and factors influencing intention to use bikeshare services. 334 participants from Beijing, China, completed a questionnaire including the Big Five Inventory, the Traffic Climate Scale, and measurements of attitude toward and intention to use bikesharing. The results showed that attitude toward bikesharing was positively predicted by extroversion, the functionality of the traffic climate, social support and personal preference. Additionally, social support, personal preference and attitude toward bikesharing positively predicted the intention to use bikesharing. Young people were more willing to use bikesharing services. This study provides a framework for bikeshare usage and the related influencing factors. Related suggestions and strategies from policymaking and marketing perspectives are proposed to encourage more residents to adopt bikesharing. Some of the limitations and possible extensions of this field are discussed
The effect of the emotional state on driving performance in a simulated car-following task
Emotion is an important factor that influences driving behavior, but the mechanism is unclear. This research explored the effect of the emotional state on simulated driving behavior. Thirty-five licensed drivers participated in this study and completed a car-following task. The angry, happy and neutral states were manipulated during the task. The participants' driving performance and risk perception were recorded under each emotional state. Trait anger and driving experience were also measured to explore the possible mediating effect. The results showed that the drivers in an angry or happy emotional state tended to maintain less time to collision and take a longer time to brake while following a lead vehicle than the drivers under the neutral condition, suggesting that drivers in emotional states are more dangerous those in neutral states. Moreover, the happy state rendered the drivers more dangerous, which manifested as a lower perceived accident risk than that among the drivers in the angry and neutral states. More specifically, experienced drivers in happy states performed worse with respect to vehicle lateral position control. Recommendations and implications for safety education and further research are discussed. (C) 2020 Elsevier Ltd. All rights reserved.</p
Effect of personality traits, age and sex on aggressive driving: Psychometric adaptation of the Driver Aggression Indicators Scale in China
This study aimed to assess the reliability and validity of the Chinese version of the Driver Aggression Indicators Scale (DAIS), which measures aggressive driving behaviors. Besides, demographic variables (sex and age) and the big five personality traits were examined as potential impact factors of aggressive driving. A total of 422 participants completed the DAIS, Big Five Personality Inventory (BFPI), and the socio-demographic scale. First, psychometric results confirmed that the DAIS had a stable two-factor structure and acceptable internal consistency. Then, agreeableness and conscientiousness were negatively correlated with hostile aggression and revenge committed by the drivers themselves, while neuroticism was positively correlated with aggressive driving committed by the drivers themselves. Meanwhile, more agreeable drivers may perceive less hostile aggression and revenge. More neurotic drivers may perceive more aggressive warning. Finally, the effects of age and sex on aggressive driving were not same as most studies. We found that older age group perceived and committed more hostile acts of aggression and revenge than younger age groups. Female drivers of 49-60 years perceived more aggressive warnings committed by other drivers.</p
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