scholarly journals Analysis of the sensitivity of the impact resonance frequency test as a tool to determine the elastic properties of bituminous materials

2017 ◽  
Vol 7 (080) ◽  
pp. 131 ◽  
Author(s):  
R. Tauste ◽  
F. Moreno-Navarro ◽  
R. Gallego ◽  
M. C. Rubio-Gámez
Keyword(s):  
Resonance Frequency ◽  
Elastic Properties ◽  
Damage State ◽  
Bituminous Mixtures ◽  
Bituminous Materials ◽  
Key Factor ◽  
Repeatability And Reproducibility ◽  
Impact Resonance ◽  
The Impact ◽  
Non Destructive

The modulus value of bituminous materials is a key factor in the design of road pavements and the estimation of their life service. This parameter can be measured in laboratory but, unfortunately, this requires the deterioration of the pavement so as the consumption of time and resources. Therefore, this study analyses the feasibility of using impact resonance frequency tests as an alternative to traditional methods for determining the dynamic modulus of bituminous mixtures. The sensitivity of this technique has been studied by analyzing its repeatability and reproducibility, studying the variations in the values measured by modifying the dimensions of the specimens, test temperatures and types of mixture tested. In addition, this non-destructive technique has been compared with other traditional tests used to determine the elastic properties of bituminous materials. The results show that this test could be an interesting tool to characterize the properties and damage state of asphalt layers.

scholarly journals Dynamic Measurements for Determining Poisson’s Ratio of Young Concrete

2018 ◽  
Vol 58 (1) ◽  
pp. 95-106 ◽  
Author(s):  
Lamis Ahmed
Keyword(s):  
Poisson’S Ratio ◽  
Resonance Method ◽  
Poisson's Ratio ◽  
Early Age ◽  
A Value ◽  
Young Concrete ◽  
Impact Resonance ◽  
Set Up ◽  
The Impact ◽  
Non Destructive

Abstract Knowledge of the elastic properties of concrete at early age is often a pre-requisite for numerical calculations. This paper discusses the use of a laboratory technique for determining Poisson’s ratio at early concrete age. A non-destructive test set-up using the impact resonance method has been tested and evaluated. With the method, it has been possible to obtain results already at 7 hours of concrete age. Poisson’s ratio is found to decrease sharply during the first 24 hours to reach a value of 0.08 and then increase to approximately 0.15 after seven days.

Competition Policy under Economic Crisis

2009 ◽  
pp. 54-69 ◽  
Author(s):  
A. Shastitko ◽  
S. Avdasheva ◽  
S. Golovanova
Keyword(s):  
Division Of Labor ◽  
Economic Crisis ◽  
Industrial Policy ◽  
Competition Policy ◽  
Transition Economy ◽  
Economic Recession ◽  
Price Rigidity ◽  
Key Factor ◽  
Policy Measures ◽  
The Impact

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.

Designing a CRM Framework for online & offline sports footwear retailers

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Rodrigo Cueva ◽  
Guillem Rufian ◽  
Maria Gabriela Valdes
Keyword(s):  
Environmental Changes ◽  
Customer Relationship ◽  
Business Strategies ◽  
Economic Sectors ◽  
Running Shoes ◽  
Brick And Mortar ◽  
Key Factor ◽  
On Line ◽  
The Impact

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.

Correlation of Altmetric Attention Scores with Citations in Major Pharmacy Journals (Preprint)

2018 ◽  
Author(s):  
Dave L Dixon ◽  
William L Baker
Keyword(s):  
Citation Count ◽  
Cross Sectional Study ◽  
Scientific Output ◽  
Cross Sectional ◽  
Promotion And Tenure ◽  
Article Type ◽  
Key Factor ◽  
Number Of Citations ◽  
The Impact

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.

scholarly journals Air mediates the impact of a compliant hemisphere on a rigid smooth surface

Soft Matter ◽  
2021 ◽  
Author(s):  
Siqi Zheng ◽  
Sam Dillavou ◽  
John M. Kolinski
Keyword(s):  
Elastic Body ◽  
Elastic Properties ◽  
Impact Velocity ◽  
Solid Surface ◽  
High Speed ◽  
Smooth Surface ◽  
High Speed Imaging ◽  
The Impact ◽  
Rigid Smooth

When a soft elastic body impacts upon a smooth solid surface, the intervening air fails to drain, deforming the impactor. High-speed imaging with the VFT reveal rich dynamics and sensitivity to the impactor's elastic properties and the impact velocity.

scholarly journals Exploring the Effects of Problematic Internet Use on Adolescent Sleep: A Systematic Review

2021 ◽  
Vol 18 (2) ◽  
pp. 760
Author(s):  
Ioulia Kokka ◽  
Iraklis Mourikis ◽  
Nicolas C. Nicolaides ◽  
Christina Darviri ◽  
George P. Chrousos ◽  
...  
Keyword(s):  
Internet Use ◽  
Educational Interventions ◽  
The Body ◽  
Problematic Internet Use ◽  
Affecting Factors ◽  
Physical And Mental Health ◽  
Adolescent Sleep ◽  
Key Factor ◽  
Parental Educational Level ◽  
The Impact

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.

The impact of different proportions of knitting elements on the resistive properties of conductive fabrics

2018 ◽  
Vol 89 (5) ◽  
pp. 881-890 ◽  
Author(s):  
Su Liu ◽  
Yanping Liu ◽  
Li Li
Keyword(s):  
Contact Resistance ◽  
Reference Source ◽  
Wearable Electronics ◽  
Electronic Textiles ◽  
Knitted Fabrics ◽  
Conductive Yarns ◽  
Key Factor ◽  
Resistive Networks ◽  
The Impact ◽  
Resistive Property

Conductive yarn is the key factor in fabricating electronic textiles. Generally, three basic fabric production methods (knit, woven, and non-woven) combined with two finishing processes (embroidery and print) are adopted to embed conductive yarns into fabrics to achieve flexible electronic textiles. Conductive yarns with knit structure are the most flexible and effective form of electronic textiles. Electronic textiles present many advantages over conventional electronics. However, in the process of commercialization of conductive knitted fabrics, it is a great challenge to control the complicated resistive networks in conductive knitted fabrics for the purpose of cost saving and good esthetics. The resistive networks in conductive knitted fabrics contain length-related resistance and contact resistance. The physical forms of conductive yarns in different fabrication structures can be very different and, thus, the contact resistance varies greatly in different fabrics. So far, study of controlling the resistive property of conductive fabrics has not been conducted. Therefore, establishing a systematic method for the industry as a reference source to produce wearable electronics is in great demand. During the industrialization of conductive knitted fabrics, engineers can estimate the resistive property of the fabric in advance, which makes the production process more effective and cost efficient. What is more, the resistive distribution in the same area of knitted fabrics can be fully controlled.

scholarly journals Integrative analysis of <i>Geobacter</i> spp. and sulfate-reducing bacteria during uranium bioremediation

2012 ◽  
Vol 9 (3) ◽  
pp. 1033-1040 ◽  
Author(s):  
M. Barlett ◽  
K. Zhuang ◽  
R. Mahadevan ◽  
D. Lovley
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Field Trials ◽  
Second Phase ◽  
Sulfate Reducing ◽  
Organic Electron ◽  
Poor Understanding ◽  
Key Factor ◽  
Reducing Bacteria ◽  
The Impact

Abstract. Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

Predicting the Influence of Damping Devices on the Stability Margin of an Annular Combustor

2017 ◽  
Author(s):  
Max Zahn ◽  
Michael Betz ◽  
Moritz Schulze ◽  
Christoph Hirsch ◽  
Thomas Sattelmayer
Keyword(s):  
Resonance Frequency ◽  
Stability Margin ◽  
Numerical Approach ◽  
Acoustic Mode ◽  
Acoustic Properties ◽  
Azimuthal Mode ◽  
Acoustic Damping ◽  
Linearized Euler Equations ◽  
Annular Combustor ◽  
The Impact

A numerical modeling approach based on linearized Euler equations is applied to predict the linear stability of an annular combustor with and without dampers. The acoustic properties of all relevant combustor components such as damping devices, swirl burner characteristics, swirl flame dynamics, and combustor exit are individually evaluated via experimental and numerical approaches. All of the components are incorporated subsequently into the combustor model using impedances and acoustic transfer matrices to obtain an efficient procedure. This study focuses on using this approach to predict an annular combustor’s stability margin and to assess how dampers influence the modal dynamics of the first azimuthal mode. Stability predictions are successfully validated with experimental data. Different combustor components’ contributions to the acoustic damping of the entire system is also determined based on that numerical approach. Damper application in combustors can engender uncertainties in resonance frequency in the case of hot-gas ingestion. The impact of “detuned” resonators on the predicted damping rates with respect to a deviation in the resonance frequency and the eigenfrequency of the attenuated acoustic mode is therefore evaluated. The influence of dampers on the annular combustor’s stability margin is also determined.

scholarly journals The perceived impact of downsizing and organisational transformation on survivors

2005 ◽  
Vol 31 (2) ◽  
Author(s):  
N. Ndlovu ◽  
S. Brijball Parumasur
Keyword(s):  
Change Implementation ◽  
Way Of Life ◽  
Advancement Opportunities ◽  
Survivor Syndrome ◽  
Framework Model ◽  
Key Factor ◽  
Major Transformation ◽  
Perceived Impact ◽  
The Impact ◽  
Implementation Factors

Change is a way of life and the ability to manage change is a key factor in organisational survival and effectiveness. This article evaluates the ‘survivor syndrome’ and assesses the impact of the process of downsizing and transformation on communication, trust, survivor commitment and loyalty, morale and career advancement opportunities. The study was conducted using a stratified random sample of 361 employees/survivors in a branch of a motor manufacturer that had undergone major transformation. Data was collected using a self-developed questionnaire and analysed using descriptive and inferential statistics. The study generates a framework/model of critical change implementation factors and recommendations that will enable change managers to sense, adjust, respond and implement change timeously so as to gain strategic and competitive advantage. Opsomming Verandering is ’n lewenswyse en die vermoë om te verander is ’n kernaspek in organisasieverandering en -oorlewing. In hierdie artikel word die ‘oorlewingsindroom’ beoordeel en word die impak van die afskalingsproses en transformasie op kommunikasie, vertroue, ‘oorlewende’ toewyding en lojaliteit, moraal en loopbaanvorderingsgeleenthede takseer. Die studie is uitgevoer, met die gebruik van ’n gestratifiseerde ewekansige steekproef van 361 werknemers/’oorlewendes’ in ’n afdeling van ’n motorvervaardiger wat ingrypende transformasie ondergaan het. Data is ingesamel by wyse van ’n selfontwikkelde vraelys en ontleed aan die hand van beskrywende en inferensiële statistiek. Die studie het ’n raamwerk/model van kritieke veranderingsimplementeringsfaktore en aanbevelings gegenereer wat veranderingsbestuurders in staat sal stel om die gewaarwording, aanpassing, reaksie en implementering van verandering tydig te doen sodat strategiese en mededingingsvoordeel behaal kan word.

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