Numerical Analysis of the Effect of Roadside Accumulated Water on Subgrade Temperature Field in the Freezing Region

2013 ◽  
Vol 470 ◽  
pp. 284-288
Author(s):  
Qing Meng Meng ◽  
Xue Song Mao ◽  
Yu Shuo Fan ◽  
Si De Ling ◽  
Xuan Xiao

The change of moisture-heat is the key factor that influences the seasonal freezing subgrade stability. In order to analyze the impact of the moisture on temperature field in the seasonal frozen subgrade, this paper established seasonal freezing subgrade model, calculated and analyzed the effects of subgrade temperature field in the middle of road, shoulder, slope and outside of slope with roadside accumulated water, based on the change of temperature field control equation. This research showed that roadside accumulated water has a significant influence on the subgrade temperature field. The results showed the range of 0°C isotherm under the accumulated water was bigger than normal subgrade, and the depth of 0°C isotherm was deeper under the accumulated water than normal.

2014 ◽  
Vol 505-506 ◽  
pp. 168-173
Author(s):  
Nan Wang ◽  
Qing Meng Meng ◽  
Jin Feng Yang

The change of moisture and temperature is the key factor that influences the permafrost roadbed stability. Based on Moisture-Heat control equation and permafrost sub-grade deformation control equation, the permafrost sub-grade model was established. Studies showed that roadside accumulated water had remarkable influences on deformation of sub-grade; Moisture infiltration contributed to the production of longitudinal crack, and the longitudinal cracks were likely to be developed at the roadside where the water was accumulated for the longer time , and the greater changing of longitudinal cracks were developed.


Author(s):  
Marcin Figat ◽  
Paulina Piątkowska

This article presents the numerical analysis of the aerodynamic impact of the fuselage on propeller performance in the pusher configuration and the propeller impact on the flow around the fuselage. The main aim of the presented investigation was to find the magnitude of the interaction between the propeller and the fuselage. This effect was evaluated based on the analysis of the change of the fuselage drag and the propeller thrust according to the change of the propeller's geometry. All obtained results allowed to prepare the methodology for choosing the best propeller geometry for the aircraft in the pusher configuration. During the investigation, the impact of the propeller geometry on the results was analysed. First of all, the change of the blade pitch ratio and the propeller radius was tested. Computation was made for numerous flight conditions and propeller rotation rate. As a main result, the relation between the propeller performance and the fuselage in the pusher configuration was found. Especially, the significant influence on the propeller thrust caused by the fuselage and the influence on the fuselage drag caused by the propeller were observed. Finally, all the obtained outcomes were used to create a knowledge base, which was next used to select the best propeller geometry to satisfy the required power condition for a level flight for the newly designed aircraft PW-Chimera.


2011 ◽  
Vol 221 ◽  
pp. 604-609 ◽  
Author(s):  
Dong Xing Du ◽  
Ying Ge Li ◽  
Xiao Bing Luo

The working temperature has great effect on the reliability of LED modules. In this paper, numerical analysis is carried out on predicting the temperature field in a LED module based on simplified two-dimensional model. It is found that the highest temperature manifests in the LED chip and more than 99% of the heat generated by the LED chip are transferred out through the copper heat sink. Parametric study shows significant temperature increment from 327K to 384K in the LED lighting chip by decreasing 10 times of the thermal conductivity values of conductive layer from 24.5W/(m.K) to 2.45W/(m.K). It is concluded that the key factor in heat transfer process inside the LED module is the thermal resistance of the thermal conductive layer lying between LED chip and copper heat sink.


2009 ◽  
pp. 54-69 ◽  
Author(s):  
A. Shastitko ◽  
S. Avdasheva ◽  
S. Golovanova

The analysis of competition policy under economic crisis is motivated by the fact that competition is a key factor for the level of productivity. The latter, in its turn, influences the scope and length of economic recession. In many Russian markets buyers' gains decline because of the weakness of competition, since suppliers are reluctant to cut prices in spite of the decreasing demand. Data on prices in Russia and abroad in the second half of 2008 show asymmetric price rigidity. At least two questions are important under economic crisis: the 'division of labor' between pro-active and protective tools of competition policy and the impact of anti-crisis policy on competition. Protective competition policy is insufficient in transition economy, especially in the days of crisis it should be supplemented with the well-designed industrial policy measures which do not contradict the goals of competition. The preferable tools of anti-crisis policy are also those that do not restrain competition.


Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes

The use of Customer Relationship Managers to foster customers loyalty has become one of the most common business strategies in the past years.  However, CRM solutions do not fill the abundance of happily ever-after relationships that business needs, and each client’s perception is different in the buying process.  Therefore, the experience must be precise, in order to extend the loyalty period of a customer as much as possible. One of the economic sectors in which CRM’s have improved this experience is retailing, where the personalized attention to the customer is a key factor.  However, brick and mortar experiences are not enough to be aware in how environmental changes could affect the industry trends in the long term.  A base unified theoretical framework must be taken into consideration, in order to develop an adaptable model for constructing or implementing CRMs into companies. Thanks to this approximation, the information is complemented, and the outcome will increment the quality in any Marketing/Sales initiative. The goal of this article is to explore the different factors grouped by three main domains within the impact of service quality, from a consumer’s perspective, in both on-line and off-line retailing sector.  Secondly, we plan to go a step further and extract base guidelines about previous analysis for designing CRM’s solutions focused on the loyalty of the customers for a specific retailing sector and its product: Sports Running Shoes.


2018 ◽  
Author(s):  
Dave L Dixon ◽  
William L Baker

BACKGROUND The impact and quality of a faculty members publications is a key factor in promotion and tenure decisions and career advancement. Traditional measures, including citation counts and journal impact factor, have notable limitations. Since 2010, alternative metrics have been proposed as another means of assessing the impact and quality of scholarly work. The Altmetric Attention Score is an objective score frequently used to determine the immediate reach of a published work across the web, including news outlets, blogs, social media, and more. Several studies evaluating the correlation between the Altmetric Attention Score and number of citations have found mixed results and may be discipline-specific. OBJECTIVE To determine the correlation between higher Altmetric Attention Scores and citation count for journal articles published in major pharmacy journals. METHODS This cross-sectional study evaluated articles from major pharmacy journals ranked in the top 10% according to the Altmetric Attention Score. Sources of attention that determined the Altmetric Attention Score were obtained, as well each articles open access status, article type, study design, and topic. Correlation between journal characteristics, including the Altmetric Attention Score and number of citations, was assessed using the Spearman’s correlation test. A Kruskal-Wallis 1-way analysis of variance (ANOVA) was used to compare the Altmetric Attention Scores between journals. RESULTS Six major pharmacy journals were identified. A total of 1,376 articles were published in 2017 and 137 of these represented the top 10% with the highest Altmetric Attention Scores. The median Altmetric Attention Score was 19 (IQR 15-28). Twitter and Mendeley were the most common sources of attention. Over half (56.2%) of the articles were original investigations and 49.8% were either cross-sectional, qualitative, or cohort studies. No significant correlation was found between the Altmetric Attention Score and citation count (rs=0.07, P = 0.485). Mendeley was the only attention source that correlated with the number of citations (rs=0.486, P<0.001). The median Altmetric Attention Score varied widely between each journal (P<0.001). CONCLUSIONS The overall median Altmetric Attention score of 19 suggests articles published in major pharmacy journals are near the top 5% of all scientific output. However, we found no correlation between the Altmetric Attention Score and number of citations for articles published in major pharmacy journals in the year 2017.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kaoru Tachiiri ◽  
Xuanming Su ◽  
Ken’ichi Matsumoto

AbstractFor the purpose of identifying the key processes and sectors involved in the interaction between Earth and socio-economic systems, we review existing studies on those processes/sectors through which the climate impacts socio-economic systems, which then in turn affect the climate. For each process/sector, we review the direct physical and ecological impacts and, if available, the impact on the economy and greenhouse gas (GHG) emissions. Based on this review, land sector is identified as the process with the most significant impact on GHG emissions, while labor productivity has the largest impact on the gross domestic product (GDP). On the other hand, the energy sector, due to the increase in the demand for cooling, will have increased GHG emissions. Water resources, sea level rise, natural disasters, ecosystem services, and diseases also show the potential to have a significant influence on GHG emissions and GDP, although for most of these, a large effect was reported only by a limited number of studies. As a result, more studies are required to verify their influence in terms of feedbacks to the climate. In addition, although the economic damage arising from migration and conflict is uncertain, they should be treated as potentially damaging processes.


Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 707
Author(s):  
Petros Vasilakos ◽  
Yongtao Hu ◽  
Armistead Russell ◽  
Athanasios Nenes

Formation of aerosol from biogenic hydrocarbons relies heavily on anthropogenic emissions since they control the availability of species such as sulfate and nitrate, and through them, aerosol acidity (pH). To elucidate the role that acidity and emissions play in regulating Secondary Organic Aerosol (SOA), we utilize the 2013 Southern Oxidant and Aerosol Study (SOAS) dataset to enhance the extensive mechanism of isoprene epoxydiol (IEPOX)-mediated SOA formation implemented in the Community Multiscale Air Quality (CMAQ) model (Pye et al., 2013), which was then used to investigate the impact of potential future emission controls on IEPOX OA. We found that the Henry’s law coefficient for IEPOX was the most impactful parameter that controls aqueous isoprene OA products, and a value of 1.9 × 107 M atm−1 provides the best agreement with measurements. Non-volatile cations (NVCs) were found in higher-than-expected quantities in CMAQ and exerted a significant influence on IEPOX OA by reducing its production by as much as 30% when present. Consistent with previous literature, a strong correlation of isoprene OA with sulfate, and little correlation with acidity or liquid water content, was found. Future reductions in SO2 emissions are found to not affect this correlation and generally act to increase the sensitivity of IEPOX OA to sulfate, even in extreme cases.


Author(s):  
Ioulia Kokka ◽  
Iraklis Mourikis ◽  
Nicolas C. Nicolaides ◽  
Christina Darviri ◽  
George P. Chrousos ◽  
...  

Adolescent suse internet via several devices to gather information or communicate. Sleep, as a key factor of adolescents’ development, contributes to their physical and mental health. Over the past decades insufficient sleep among adolescents has been wide spread, and one of its attributing factors is the increased availability of technology. This review aims to investigate the body of evidence regarding the impact of problematic internet use on adolescent sleep. Extensive search of databases was performed according to PRISMA guidelines for studies published within the last decade, regarding subjects aged 10–19. The final step of the search yielded 12 original studies. The quality of extracted data was evaluated with the AXIS tool, in order to estimate the risk of bias. All studies showed a negative correlation between adolescent sleep and problematic internet use. It was found to affect sleep quality and quantity and provoke insomnia symptoms. Interestingly, adolescent’s sex, parental educational level, type of family and use for leisure or academic reasons appeared as affecting factors of the problematic internet use-sleep relationship. Problematic internet use has several effects on adolescents’ sleep. Results of relevant studies should be embedded in educational interventions addressed to adolescents as well as parents, to eliminate the negative outcomes of problematic internet use on sleep and adolescence’s health in general.


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