1,020 research outputs found
Cohesive Soil Stabilized Using Sewage Sludge Ash/Cement and Nano Aluminum Oxide
ABSTRACTIn order to improve soft soil strength, a mixture of incinerated sewage sludge ash (SSA) and cement was applied as a soil stabilizer. The intended mix ratio for SSA and cement was 3:1. A-6 clay was selected as the untreated soil. In this study, 15% of clay soil was replaced by SSA/cement to produce the treated soil specimens. Then, four different volumes, namely 0, 1, 2, and 3%, of nano-Al2O3 were mixed with the treated soil as an additive. Tests such as compaction, pH values, Atterberg limits, unconfined compressive strength (UCS), swell potential, California bearing ratio (CBR), and permeability were performed. The results indicate that both UCSs and CBR values of untreated soil were greatly improved by the use of 15% SSA/cement. Moreover, a 1% addition of nano-Al2O3 enhanced the treated soil in terms of both UCS and CBR values. Furthermore, the swell potential was effectively reduced by the use of 15% SSA/cement as compared with untreated soil and the 1% nano-Al2O3 additive fraction offered the best performance. From this study, we conclude that 15% of SSA/cement replacement could effectively stabilize A-6 clay soil, and 1% of nano-Al2O3 additive may be the optimum amount to add to the soil
Influence of defects on the electronic and magnetic properties of half-metallic CrAs, CrSe and CrSb zinc-blende compounds
We present an extended study of single impurity atoms and atomic swaps in
half-metallic CrAs, CrSb and CrSe zinc-blende compounds. Although the perfect
alloys present a rather large gap in the minority-spin band, all defects under
study, with the exception of void impurities at Cr and sp sites and Cr
impurities at sp sites (as long as no swap occurs), induce new states within
the gap. The Fermi level can be pinned within these new minority states
depending on the lattice constant used for the calculations and the
electronegativity of the sp atoms. Although these impurity states are localized
in space around the impurity atoms and very fast we regain the bulk behavior,
their interaction can lead to wide bands within the gap and thus loss of the
half-metallic character
Effect of a qigong intervention program on telomerase activity and psychological stress in abused Chinese women: a randomized, wait-list controlled trial
BACKGROUND: Abused women, who suffer from chronic psychological stress, have been shown to have shorter telomeres than never abused women. Telomere shortening is associated with increased risk of cell death, and it is believed that adopting health-promoting behaviors can help to increase the activity of telomerase, an enzyme that counters telomere shortening. Qigong is an ancient Chinese mind-body integration, health-oriented practice designed to enhance the function of qi, an energy that sustains well-being. Therefore, an assessor-blind, randomized, wait-list controlled trial was developed to evaluate the effect of a qigong intervention on telomerase activity (primary objective) and proinflammatory cytokines, perceived stress, perceived coping, and depressive symptoms (secondary objectives) in abused Chinese women. METHODS/DESIGN: A total of 240 Chinese women, aged >/= 18 years, who have been abused by an intimate partner within the past three years will be recruited from a community setting in Hong Kong and randomized to receive either a qigong intervention or wait-list control condition as follows: the qigong intervention will comprise (i) a 2-hour group qigong training session twice a week for 6 weeks, (ii) a 1-hour follow-up group qigong exercise session once a week for 4 months, and (iii) a 30-minute self-practice qigong exercise session once a day for 5.5 months. The wait-list control group will receive qigong training after the intervention group completes the program. Upon completion of the qigong intervention program, it is expected that abused Chinese women in the intervention group will have higher levels of telomerase activity and perceived coping and lower levels of proinflammatory cytokines, perceived stress, and depressive symptoms than will abused Chinese women in the wait-list control group. DISCUSSION: This study will provide information about the effect of qigong exercise on telomerase activity and chronic psychological stress in abused Chinese women. The findings will inform the design of interventions to relieve the effects of IPV-related psychological stress on health. Also, the concept that health-promoting behaviors could slow down cellular aging might even motivate abused women to change their lifestyles. TRIAL REGISTRATION: Current Controlled Trials NCT02060123. Registered February 6, 2014.published_or_final_versio
Calibrating CHIME, A New Radio Interferometer to Probe Dark Energy
The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a transit
interferometer currently being built at the Dominion Radio Astrophysical
Observatory (DRAO) in Penticton, BC, Canada. We will use CHIME to map neutral
hydrogen in the frequency range 400 -- 800\,MHz over half of the sky, producing
a measurement of baryon acoustic oscillations (BAO) at redshifts between 0.8 --
2.5 to probe dark energy. We have deployed a pathfinder version of CHIME that
will yield constraints on the BAO power spectrum and provide a test-bed for our
calibration scheme. I will discuss the CHIME calibration requirements and
describe instrumentation we are developing to meet these requirements
Electric-field-induced Three-terminal pMTJ Switching in the absence of an External Magnetic Field
Since it is undesirable to require an external magnetic field for on-chip
memory applications, we investigate the use of a Rashba effective field
alternatively for assisting the electric-field-induced switching operation of a
three terminal perpendicular magnetic tunnel junction (pMTJ). By conducting
macro-spin simulation, we show that a pMTJ with thermal stability of 61 can be
switched in 0.5 ns consuming a switching energy of 6 fJ, and the voltage
operation margin can be improved to 0.8 ns. Furthermore, the results also
demonstrate that a heavy metal system that can provide large field-like torque
rather than damping-like torque is favored for the switching.Comment: there are 10 pages and 5 figures in this fil
Cross-channel marketing on e-commerce marketplaces: impact and strategic budget allocation
Problem definition: As the ecosystem of e-commerce marketplaces becomes more competitive, retailers on the marketplaces are increasingly relying on cross-channel marketing to access potential customers. Despite the growing popularity and widely expected benefits of cross-channel marketing, retailers may find it difficult to allocate their budget to various marketing channels with different characteristics.
Methodology/results: Using data from a world-leading retailer on a popular e-commerce marketplace, we empirically verify and quantify the impact of cross-channel marketing on boosting the retailer's revenue. Specifically, we identify important promotional, cross-period spillover, and cross-product spillover effects that should be included in the analysis. Incorporating empirical estimations into an optimization model, we propose an empirically-grounded modeling framework for optimizing marketing budget allocation in the marketplace. Our study suggests that this framework can substantially improve the retailer's profit.
Managerial implications: We find it worthwhile for a retailer to adopt cross-channel marketing by investing in various channels to engage customers in different scenarios. We guide retailers to strategically invest in different marketing channels on e-commerce marketplaces. For marketing channels designed to spotlight products on a marketplace homepage (Banner), the retailer should invest in them when it is near promotion periods. Second, the retailer should allocate more budget to recommendation channels (Recommender) that can reach relevant customers throughout their shopping journey especially during promotion periods. Third, the retailer should focus her investment on pre-promotion periods for marketing channels that prioritize products in keyword search (SEO-product), while keeping a relatively high investment in other periods. In contrast, for marketing channels that rank online stores in keyword search (SEO-store), the retailer should maintain a relatively steady investment across different periods
Urban consolidation center or peer-to-peer platform? The solution to urban last-mile delivery
4pi Models of CMEs and ICMEs
Coronal mass ejections (CMEs), which dynamically connect the solar surface to
the far reaches of interplanetary space, represent a major anifestation of
solar activity. They are not only of principal interest but also play a pivotal
role in the context of space weather predictions. The steady improvement of
both numerical methods and computational resources during recent years has
allowed for the creation of increasingly realistic models of interplanetary
CMEs (ICMEs), which can now be compared to high-quality observational data from
various space-bound missions. This review discusses existing models of CMEs,
characterizing them by scientific aim and scope, CME initiation method, and
physical effects included, thereby stressing the importance of fully 3-D
('4pi') spatial coverage.Comment: 14 pages plus references. Comments welcome. Accepted for publication
in Solar Physics (SUN-360 topical issue
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