1,815 research outputs found
Composition-induced structural phase transitions in the (Ba1xLax)2In2O5+x (0pxp0.6) system
Composition-induced structural phase changes across the high temperature, fast oxide ion conducting (Ba1xLax)2In2O5+x, 0pxp0.6, system have been carefully analysed using hard mode infrared (IR) powder absorption spectroscopy, X-ray powder diffraction and electron diffraction. An orthorhombic brownmillerite to three-dimensionally disordered cubic perovskite phase transition in this system is signalled by a drastic change in slope of both wavenumber and average line widths of IR spectra as a function of composition. Some evidence is found for the existence of an intermediate tetragonal phase (previously reported to exist from electron diffraction data) around x 0:2: The new spectroscopic data have been used to compare microscopic and macroscopic strain parameters arising from variation in composition. The strain and spectroscopic data are consistent with firstorder character for the tetragonal-orthorhombic transition, while the cubic-tetragonal transition could be continuous. Differences between the variation with composition of spectral parameters and of macroscopic strain parameters are consistent with a substantial order/disorder component for the transitions. There is also evidence for precursor effects within the cubic structure before symmetry is broken
A Cross-Cultural Study of the Relation Between Degree of American Acculturation and Androgyny
Problem. Research has identified culture as one of the factors which reinforces sex-appropriate behaviors and punishes inappropriate behaviors for each gender. The purpose of this study was to validate the theory that culture is an influencing factor in the development of sex-role acquisition through studying two diversely different cultures.
Method. This study employed the Bem Inventory for the measurement of sex-role typing. There were a total of 374 college-age females from either a Chinese culture or Anglo-American culture who participated in the study.The subjects were divided into five groups according to the degree of American acculturation. Three null hypotheses were postulated.
Findings. (1) There were significantly more Anglo-American females in the sex-typed category called androgynous as compared to the four Chinese female groups. (2) There was a higher percentage of Anglo-American females in Bem\u27s feminine category than Chinese females from Hong Kong and Singapore. (3) The percentage of females in the undifferentiated category was higher for all four Chinese groups as compared to the Anglo-American group. (4) The proportion of subjects in the androgynous category increased as expected from Group 1 to Group 5 with the exception of Group 4. (5) The Hong Kong and Singapore Chinese group had the highest proportion of females classified in the masculine category, and the lowest proportion in the feminine category. (6) There were significant differences in both masculinity and femininity mean scores among the five groups. (7) Both Anglo-American females and Chinese females who came to the United States before the age of ten had a masculine mean score which was significantly higher than that of Chinese females from Hong Kong and Singapore. (8) American-born Chinese females generally scored low in masculine and feminine scales as compared to the Chinese who came to the United States before the age of ten. (9) Chinese females from Hong Kong and Singapore had a significantly lower femininity mean score as compared to all the other groups.
Conclusions. The findings in this study validated culture as an influencing factor in the acquisition of sex-role. Based on the assumption that the Anglo-American culture is more androgynous, results indicated that there were a higher percentage of Anglo-American females than of Chinese females classified as androgynous. It verified the hypothesis which posited that there is a relation between sex-role typing and the degree of American acculturation
Assessing Complete Street Strategies Using Microscopic Traffic Simulation Models
Authors of this research developed a traffic simulation model for the downtown San Jose network and evaluated five different street redesign and travel demand combinations. This model aids understanding of network-wide effects of changes in street design for local and regional agencies who are interested in implementing complete streets and/or one-way to two-way conversion. The base network may be altered to model and evaluate other complete streets (e.g., road diet) and tactical urbanism (e.g., farmer’s market on city streets on certain days of the week) scenarios. The 3-dimensional animated videos for each scenario are also created to be used for public outreach by the city to engage the stakeholders in the planning and implementation process. Quantitative measures used for evaluating the scenarios include travel times on key corridors and network-wide delays during the afternoon peak hour. The evaluation shows the current city street network will be able to sustain a modest (between 5% and 10%) increase in single-occupancy automobile travel demand. The network will be overwhelmed if the single-occupancy automobile travel demand were to increase to the level projected per the city’s 2040 general plan. This outcome points to the need for strong Travel Demand Management (TDM) measures
High flux thin-film nanocomposites with embedded boron nitride nanotubes for nanofiltration
A novel thin film nanocomposite (TFN) membrane was obtained by incorporating boron nitride nanotubes (BNNTs) into a polyamide (PA) thin selective layer prepared via interfacial polymerisation. The addition of just 0.02 wt% of BNNTs led to a 4-fold increase in pure water permeance with no loss in rejection for divalent salts, methylene blue or humic acid compared to the pure PA membrane. Loadings higher than 0.02 wt% of BNNTs led to agglomeration with overall loss of performance. For the membranes containing 0.02 wt% BNNTs, the pure water permeance was 4.5 LMH@bar, with >90% rejection of MgSO4 and >80% rejection of CaCl2. Fouling tests with humic acid showed a flux recovery ratio of >95% with ~50% lower flux loss during the fouling cycle compared to the polyamide only membrane. These values represent a significant improvement over both commercial polyamide membranes and TFN membranes incorporating carbon nanotubes. We assert that the very small quantity of BNNTs needed to produce the enhanced performance opens the way to their use in water treatment applications where nanofiltration membranes are subject to severe organic fouling.</p
Microscopic traffic simulation as a decision support system for road diet and tactical urbanism strategies
Urban street networks in the United States have been primarily designed for automobile traffic with negligible considerations to non-motorized transportation users. Due to environmental issues and quality of life concerns, communities are reclaiming street spaces for active modes and slowing the speeds in their downtown. Moreover, tactical urbanism, i.e., the use of street space for innovative purposes other than moving automobile traffic, is becoming attractive due to reduced automobile travel demand and the need for outdoor activities in the age of the COVID-19 pandemic. This study provides details of the modeling of an urban downtown network (in the City of San Jose) using microscopic traffic simulation. The model is then applied to evaluate the effectiveness of street design changes at varying demand scenarios. The microsimulation approach was chosen because it allows for the detailed modeling and visualization of the transportation networks, including movements of individual vehicles, bicyclists, and pedestrians. The street design change demonstrated here involves one-way to two-way street conversion, but the framework of network-wide impact evaluation may also be used for complete street conversions. The base conditions network was also tested under different travel demand reduction scenarios (10%, 20%, and 30%) to identify the corridors in the city network in which the tactical urbanism strategies (e.g., open-air dining) may be best accommodated. The study provides framework for the use of a microscopic model as part of a decision support system to evaluate and effectively implement complete streets/tactical urbanism strategies
High flux thin-film nanocomposites with embedded boron nitride nanotubes for nanofiltration
A novel thin film nanocomposite (TFN) membrane was obtained by incorporating boron nitride nanotubes (BNNTs) into a polyamide (PA) thin selective layer prepared via interfacial polymerisation. The addition of just 0.02 wt% of BNNTs led to a 4-fold increase in pure water permeance with no loss in rejection for divalent salts, methylene blue or humic acid compared to the pure PA membrane. Loadings higher than 0.02 wt% of BNNTs led to agglomeration with overall loss of performance. For the membranes containing 0.02 wt% BNNTs, the pure water permeance was 4.5 LMH@bar, with >90% rejection of MgSO4 and >80% rejection of CaCl2. Fouling tests with humic acid showed a flux recovery ratio of >95% with ~50% lower flux loss during the fouling cycle compared to the polyamide only membrane. These values represent a significant improvement over both commercial polyamide membranes and TFN membranes incorporating carbon nanotubes. We assert that the very small quantity of BNNTs needed to produce the enhanced performance opens the way to their use in water treatment applications where nanofiltration membranes are subject to severe organic fouling.</p
DIAMOND: Taming Sample and Communication Complexities in Decentralized Bilevel Optimization
Decentralized bilevel optimization has received increasing attention recently
due to its foundational role in many emerging multi-agent learning paradigms
(e.g., multi-agent meta-learning and multi-agent reinforcement learning) over
peer-to-peer edge networks. However, to work with the limited computation and
communication capabilities of edge networks, a major challenge in developing
decentralized bilevel optimization techniques is to lower sample and
communication complexities. This motivates us to develop a new decentralized
bilevel optimization called DIAMOND (decentralized single-timescale stochastic
approximation with momentum and gradient-tracking). The contributions of this
paper are as follows: i) our DIAMOND algorithm adopts a single-loop structure
rather than following the natural double-loop structure of bilevel
optimization, which offers low computation and implementation complexity; ii)
compared to existing approaches, the DIAMOND algorithm does not require any
full gradient evaluations, which further reduces both sample and computational
complexities; iii) through a careful integration of momentum information and
gradient tracking techniques, we show that the DIAMOND algorithm enjoys
in sample and communication complexities for
achieving an -stationary solution, both of which are independent of
the dataset sizes and significantly outperform existing works. Extensive
experiments also verify our theoretical findings
Peginterferon beta-1a improves MRI measures and increases the proportion of patients with no evidence of disease activity in relapsing-remitting multiple sclerosis: 2-year results from the ADVANCE randomized controlled trial
Summary of MRI endpoints over 2 years by original randomisation group [6]. (DOC 53kb
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