scholarly journals Experimental Research on the Impact of Interface Temperature on the Adhesion Properties of Clay under the Condition of Different Contacting Time

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tao Qiu ◽  
Yonggang Zhang
Keyword(s):  
Adhesion Force ◽  
Interface Temperature ◽  
Heating Process ◽  
Adhesion Properties ◽  
Interfacial Temperature ◽  
Short Time ◽  
Hot Surface ◽  
Shield Machine ◽  
The Impact

Mud cakes are very likely to occur at the shield cutter when the shield machine passes through a clay stratum, which adhere to the cutter and reduce the excavation efficiency. Due to the thrust of the cutter, the mud cakes are compacted and cause friction at the soil-structure interface, which results in high temperature and aggravates the adhesion, and the effect tends to become stronger as the heating process lasts. In this paper, the effects of the interface temperature and the contacting time between the soil and the hot surface on the adhesion properties of the soil were studied by a self-made adhesion test device. According to the findings, at low interfacial temperature (≤40°C), both the adhesion force and the amount of adhered soil were insignificant in a short term, and the effects were found to be strengthened as the contacting time went on; at the high interfacial temperature (≥50°C), very significant soil adhesion occurred at the structure surface within a short time, and as the contacting time increased, the amount of the adhered soil decreased rapidly while the adhesion force kept increasing, and both tended to remain a constant and become independent with the temperature after a long-term contact. This study is of guiding significance for understanding the formation and development of the shield mud cakes during shield construction.

scholarly journals Beyond novelty effect: a mixed-methods exploration into the motivation for long-term activity tracker use

JAMIA Open ◽  
2018 ◽  
Vol 2 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Grace Shin ◽  
Yuanyuan Feng ◽  
Mohammad Hossein Jarrahi ◽  
Nicci Gafinowitz
Keyword(s):  
Mixed Methods ◽  
Future Development ◽  
Health Informatics ◽  
Novelty Effect ◽  
Activity Tracker ◽  
Monitoring Technologies ◽  
Daily Physical Activities ◽  
Short Time ◽  
The Impact

Abstract Objectives Activity trackers hold the promise to support people in managing their health through quantified measurements about their daily physical activities. Monitoring personal health with quantified activity tracker-generated data provides patients with an opportunity to self-manage their health. Many have been conducted within short-time frames; makes it difficult to discover the impact of the activity tracker’s novelty effect or the reasons for the device’s long-term use. This study explores the impact of novelty effect on activity tracker adoption and the motivation for sustained use beyond the novelty period. Materials and methods This study uses a mixed-methods approach that combines both quantitative activity tracker log analysis and qualitative one-on-one interviews to develop a deeper behavioral understanding of 23 Fitbit device users who used their trackers for at least 2 months (range of use = 69–1073 days). Results Log data from users’ Fitbit devices revealed 2 stages: the novelty period and the long-term use period. The novelty period for Fitbit users in this study was approximately 3 months, during which they might have discontinued using their devices. Discussion The qualitative interview data identified various factors that users to continuously use the Fitbit devices in different stages. The discussion of these results provides design implications to guide future development of activity tracking technology. Conclusion This study reveals important dynamics emerging over long-term activity tracker use, contributes new knowledge to consumer health informatics and human-computer interaction, and offers design implications to guide future development of similar health-monitoring technologies that better account for long-term use in support of patient care and health self-management.

scholarly journals Effects on students of working in industry

2015 ◽  
Vol 8 (4) ◽  
pp. 32
Author(s):  
Aaron Simon Blicblau ◽  
Tracey Louise Nelson ◽  
Kourosh Dini
Keyword(s):  
Academic Performance ◽  
Project Work ◽  
Work Outcomes ◽  
Work Experiences ◽  
Short Term ◽  
Capstone Project ◽  
Academic Grades ◽  
Short Time ◽  
The Impact

This study investigated the impact of two arrangements of work experiences; short term (over 12 weeks, STIE) and long- term (over 52 weeks, LTIE) on both final academic grades and capstone project grades. The results from this work will inform future approaches of determining the benefits to students of the usefulness of industry placed learning experiences (short or long term) as both an indicator of academic performance, and success in capstone project work. Outcomes have shown that engineering graduates without substantial industrial experience often find employment difficult to find in the short time after completing their studies.

scholarly journals Experimental Research on the Impact of Temperature on the Adhesion Characteristics of Soil-Structure Interface

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tao Qiu ◽  
Cheng Liu ◽  
Xiaochun Zhong ◽  
Yueyue Zhu
Keyword(s):  
Moisture Content ◽  
Adhesion Force ◽  
Great Influence ◽  
Effect Of Temperature ◽  
Interface Temperature ◽  
Shield Tunneling ◽  
Mud Cake ◽  
Influence Of Temperature On ◽  
Cutter Head ◽  
The Impact

Under the working condition of mud cake, the continuous action between the shield cutter head and the soil on the excavation surface can generate high temperature in the process of shield tunneling and excavation, which changes the characteristic of the adhesion between the soil and the cutter head to intensify the phenomenon of making a mud cake on cutter, finally leading to a vicious circle. To study the effect of temperature on the characteristics of the adhesion of the soil on the surface of the structure, the soil adhesive situation and adhesion force at different interface temperatures were tested through a self-made experiment device. According to the result, it was indicated that the moisture content has a significant effect on the adhesion force of the soil, and the adhesion force firstly increased and then decreased with the increased of the moisture content and reached the maximum value near the plastic limit moisture content. The adhesion force changes very gently when the interface temperature is low. When the temperature reached 50°C, the adhesion force continues to increase as the interface temperature continuously increases except for the soils with high moisture content; moreover, the interface temperature has a great influence on the content of soil adhered on the structure surface. As for the soil with moderate moisture content ( ω = 21.21 ~ 31 %), this content of the adhered soil increased exponentially with the increase of interface temperature; this content firstly decreased and then increased when the moisture content was high. When the soil was dry, there was almost no adhered soil on the surface and the interface temperature had no effect on the adhesive situation. By comparing and analyzing the adhesion state of the soil on the surface of the structure, the influence of temperature on the adhesion characteristics is mainly reflected on the variation of the soil moisture content within the influence range of the interface, the variation of the energy required for the destruction of the adhesion interface, and the change of the location of the weakest antistripping plane induced by both before. This research can better understand the law of formation and development of mud cakes and provided a new idea of solving the problem of mud cakes on the cutter head.

Substrate and film structure impacts on adhesion properties between lignocellulosic polymers

2012 ◽  
Vol 1422 ◽  
Author(s):  
Elias Estephan ◽  
Véronique Aguié-Béghin ◽  
Loïc Muraille ◽  
Michael Molinari
Keyword(s):  
Plant Cell Wall ◽  
Adhesion Force ◽  
Petri Dish ◽  
Film Structure ◽  
Adhesion Forces ◽  
Concentrated Suspension ◽  
Adhesion Properties ◽  
Biochemical Processes ◽  
Langmuir Blodgett ◽  
The Impact

ABSTRACTUsing AFM, ellipsometric and profilometric measurements, we have investigated the topography and the thickness of the cellulose nanocristal (NCC) films prepared by two different methods: the first one is obtained by evaporation of concentrated suspension of NCC in petri-dish to produce a self-supported film; the second one is produced by dipping thin NCC layer on silicon substrate by Langmuir-Blodgett (LB) technique. Glucomanan (GM) functionalized AFM tip was brought into contact with these two kinds of NCC films in order to measure the adhesion between GM and NCC. The impact of the substrate and the thickness of NCC films on the measured adhesion forces were also studied: the mean measured adhesion force between the two polysaccharides was 17 nN regardless of the way the films were prepared. Adhesion properties can help us understand biochemical processes in the plant cell wall.

scholarly journals Inner-city transformation between reurbanization and gentrification: Leipzig, eastern Germany

Geografie ◽  
2015 ◽  
Vol 120 (2) ◽  
pp. 226-250 ◽  
Author(s):  
Annegret Haase ◽  
Dieter Rink
Keyword(s):  
Inner City ◽  
Spatial Differentiation ◽  
Short Time Span ◽  
Supply Surplus ◽  
Market Situation ◽  
German City ◽  
Short Time ◽  
The Impact ◽  
The City

After the beginning of the post-socialist transformation, the eastern German city of Leipzig underwent various changes within a short time span. These changes have been especially dynamic in its inner city. Whereas it was hit by the loss of large parts of its population and increasing housing vacancies in the 1990s, the 2000s brought about a revitalization and new attractiveness of many inner-city districts. Since then, reurbanization and – in some places – gentrification have become the predominant trends in a rising number of inner-city districts. This development has also reshaped patterns of socio-spatial differentiation in the city as a whole and its inner parts. Set against this background, the paper describes the development of Leipzig’s inner city after 1990. The focus of the paper is it to show how various concepts – reurbanization and gentrification – help to explain this development. Of particular interest thereby is the impact of Leipzig’s specific housing market situation that is characterized by long-term experiences of supply surplus and shrinkage.

Erosion and its Effect on a Water-Cooled Turbine

1978 ◽  
Author(s):  
Max Freedman
Keyword(s):  
Impact Velocity ◽  
Gas Turbines ◽  
Mass Loss Rate ◽  
Impact Angle ◽  
Aluminum Specimen ◽  
High Impact Velocity ◽  
Short Time ◽  
Impact Angles ◽  
The Impact

Erosion tests were run to obtain data for designing a water-cooled gas turbine collection shroud. All tests utilized a coherent stream of water ejected from a static nozzle against stationary small block specimens. Twenty-one tests were run with aluminum specimens and 16 more tests with other materials. The impact velocity was varied from 165 to 270 m/s (540 to 890 fps). The impact angle was varied from 10 to 90 deg. The mass loss rate results generally show four erosion regions, which are consistent with the literature. A correlation between regions two and four was found. Aluminum specimen erosion rate was found to be unexpectedly high with impact angles of 10 deg and moderate-to-high impact velocity. No report of previous liquid erosion work at impact angles less than 30 deg was found; since it is expected that water-cooled gas turbines will operate at impact angles of about 15 deg, erosion in this low impact angle region should be studied. If the correlation between erosion regions two and four can be quantized, then very short-time tests could be used to predict long-term erosion at minimal cost.

Gender Differences in the Social Consequences of Unemployment: How Job Loss Affects the Risk of Becoming Socially Isolated

2020 ◽  
pp. 095001702096790
Author(s):  
Jan Eckhard
Keyword(s):  
Social Isolation ◽  
Social Consequences ◽  
Small Extent ◽  
Financial Situation ◽  
The Social ◽  
Socially Isolated ◽  
Short Time ◽  
The Unemployed ◽  
The Impact

Using longitudinal data from the German Socio-Economic Panel, the study examines whether the impact of unemployment on the risk of becoming socially isolated is different for women and men and whether it can be traced back to financial straits. An isolating effect of unemployment is found only with regard to men, to long-term unemployment, and to social isolation in terms of scarce contact to friends and family. There is no such effect with regard to women, to short-time unemployment, and to social isolation in terms of a non-participation in civic associations. It is also found that the isolating impact of unemployment is only to a small extent attributable to the financial situation of the unemployed.

scholarly journals Assessment of the Impact of Accelerated Migration Testing for Coated Food Cans Using Food Simulants

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3123 ◽  
Author(s):  
Rafael Paseiro-Cerrato ◽  
Lowri DeJager ◽  
Timothy H. Begley
Keyword(s):  
Epoxy Resins ◽  
Migration Test ◽  
Food Simulants ◽  
Wide Range ◽  
Time Periods ◽  
Short Time ◽  
Storage Times ◽  
The Impact ◽  
Migration Testing

In this study, an accelerated migration test on food can coatings into food simulants was investigated. Food simulants covering a wide range of polarity were used to conduct migration tests at 60 °C with storage times ranging from 4 h to 30 days. Epoxy-resins, acrylic–phenolic, polyester, and vinyl coatings were exposed to water, 3% acetic acid, 50% ethanol, and Miglyol 812®. Using liquid chromatography coupled to a variety of detectors (UHPLC-Q-Orbitrap-MS, UFLC-MS/MS, and HPLC-DAD), migration of several monomers and previously identified oligomers, as well as some unidentified migrants, were determined during the experiment. The data from this study was compared to our findings from previous long-term migration studies with storage times ranging from 24 h to 540 days at 40 °C using the same can coating applications. The results illustrate that performing migration experiments for short time periods at 60 °C may mimic migration results that would be obtained at 40 °C after long-term migration tests (up to 1.5 years) from food can coatings into food simulants.

scholarly journals An updated overview of e-cigarette impact on human health

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Patrice Marques ◽  
Laura Piqueras ◽  
Maria-Jesus Sanz
Keyword(s):  
Human Health ◽  
Tobacco Consumption ◽  
Heating Process ◽  
Long Term Effects ◽  
Safe Alternative ◽  
The Impact ◽  
Harmful Effects

AbstractThe electronic cigarette (e-cigarette), for many considered as a safe alternative to conventional cigarettes, has revolutionised the tobacco industry in the last decades. In e-cigarettes, tobacco combustion is replaced by e-liquid heating, leading some manufacturers to propose that e-cigarettes have less harmful respiratory effects than tobacco consumption. Other innovative features such as the adjustment of nicotine content and the choice of pleasant flavours have won over many users. Nevertheless, the safety of e-cigarette consumption and its potential as a smoking cessation method remain controversial due to limited evidence. Moreover, it has been reported that the heating process itself can lead to the formation of new decomposition compounds of questionable toxicity. Numerous in vivo and in vitro studies have been performed to better understand the impact of these new inhalable compounds on human health. Results of toxicological analyses suggest that e-cigarettes can be safer than conventional cigarettes, although harmful effects from short-term e-cigarette use have been described. Worryingly, the potential long-term effects of e-cigarette consumption have been scarcely investigated. In this review, we take stock of the main findings in this field and their consequences for human health including coronavirus disease 2019 (COVID-19).

Money supply and inflation impact on economic growth

2019 ◽  
Vol 12 (1) ◽  
pp. 121-136 ◽  
Author(s):  
Dinh Doan Van
Keyword(s):  
Economic Growth ◽  
Monetary Policy ◽  
Money Supply ◽  
Karl Marx ◽  
Continuous Increase ◽  
Content Type ◽  
The Government ◽  
Short Time ◽  
The Impact

Purpose At present, countries are concerned about inflation and the impact of inflation on each country’s economic growth. This inflation has been said by economists that inflation is a phenomenon of currency and currency, which has caused inflation in some countries by their monetary policy. According to the economic theory of Karl Marx, Irving Fisher, Friedman, inflation is caused by a continuous increase in the money supply. Design/methodology/approach The economic theories of Fisher, Friedman and an econometric model are applied to analyse the relationship between money supply and inflation. Besides, Vietnam’s and China’s research data are also collected in the period of 2012-2016. Findings It is found out that the continuous increase in the money supply causes inflation in the long-term, but the continuous increase in the money supply growth does not cause inflation in a short time, this was analyzed based on the theory of monetary quantity. Moreover, Chia’s and Vietnam’s correlations of the money supply growth and inflation are 99.1 per cent. These correlations are very close. Originality/value Research results show that money supply and inflation are closely related, and the money supply directly affects economic growth. Therefore, the government should have the relevant monetary policy to grow the economy and proposals to make monetary policy, control inflation levels and stimulate economic growth.

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