Use of adhesion promoters in asphalt mixtures

The purpose of asphalt binder as a significant binder in road constructions is to permanently bind aggregates of different compositions and grain sizes. The asphalt binder itself does not have suitable adhesiveness, so after a period of time, bare grains can appear. This results in a gradual separation of the grains from an asphalt layer and the presence of potholes in a pavement. Adhesion promoters or adhesive agents are important and proven promoters in practice. They are substances mainly based on the fatty acids of polyamides which should increase the reliability of the asphalt's binder adhesion to the aggregates, thus increasing the lifetime period of the asphalt mixture as well as its resistance to mechanical strain. The amount of a promoter or agent added to the asphalt mixture is negligible and constitutes about 0.3% of the asphalt's binder weight. Nevertheless, even this quantity significantly increases the adhesive qualities of an asphalt binder. The article was created in cooperatation with the Slovak University of Technology, in Bratislava, Slovakia, and focuses on proving the new AD2 adhesive additive and comparing it with the Addibit and Wetfix BE promoters used on aggregates from the Skutec - Liticka and Bystrec quarries.Web of Science261241

Potential for improving passenger car emissions through analysis of real driving emissions data

V této práci jsou shrnuty základy motorů, prvků výfukového systému, emisí a obsahuje úvod do analýzy emisních dat a kalibrace. Na rozdílech mezi WLTC (Worldwide harmonized Light duty Test Cycle) a RDE (real driving emissions) je prezentována důležitost zahrnutí RDE testů do emisního testování. Pomocí Ricardo RDE Data Mining Tool byla provedena analýza RDE dat a byly identifikovány rizikové oblasti z hlediska aktuálních emisních limitů. Na základě této analýzy se práce zaměřila na studený start, a především na to, v jakém rozsahu se promítá do výsledků městské části RDE testu. Následně byly analyzovány absolutní hodnoty emisí za účelem nalezení provozních režimů a kombinací podmínek, které nejvíce přispívají k vyšším celkovým emisím. Na základě vyhodnocovaných dat má největší potenciál ke zlepšení emisí automobilu optimalizace úplného začátku testu/jízdy a mód vyhřívání katalyzátoru. Dále jsou popsána nejvhodnější řešení této problematiky, jako např. elektricky vyhřívaný katalyzátor.In this thesis, relevant background on emissions, engines, aftertreatment technology is summarized and introduction into emissions data analysis and calibration is presented. The importance of involving the real driving emissions (RDE) procedure into the emissions testing process was emphasized based on differences between Worldwide harmonized Light duty Test Cycle and RDE test. RDE Data Analysis through Ricardo RDE Data Mining Tool was performed and the risk areas in terms of emissions testing were identified. Based on the analysis, cold start was examined in more detail with a particular focus on its impact on the RDE urban part. Afterwards, absolute emissions analysis was carried out in order to find the periods that contributed the most to the overall emissions. The very beginning of a drive and catalyst heating mode were identified as having the greatest potential to improve the emissions of passenger cars. The most reasonable solutions, e.g. electrically heated catalyst were explored

The Role of Malagasy Women in Community Development: Analyzing the Potential for the Creation of a Women’s Association for Alternative Livelihoods in Ifaty

Integrated Conservation and development projects (ICDPs) have increased in number worldwide as conservation organizations have to come to terms with the importance of involving and addressing the needs of local human populations to order to achieve their conservation goals. Madagascar’s unique biodiversity, environmental degradation, and plaguing poverty has made ICDPs crucial in achieving national goals of tripling the area of natural heritage conserved and poverty reduction through socially, economically, and ecologically sustainable development. In order to understand how such sustainable development can be achieved, it is essential to spend time enhancing one’s understanding of the local mentality and worldview. On Madagascar’s Southwest coast, north of Tuléar, interviews were conducted with forty women in Ifaty, a rural fishing village. The intent of these interviews was to enhance the research’s understanding of the way in which these women conceive of their world: family, friends, and community. A British non-governmental organization (NGO), Reef Doctor, has been working in Ifaty since 2003. A science-based conservation NGO, Reef Doctor staff are monitoring Ifaty’s barrier reef to determine the extent of degradation, and to make informed decisions regarding ecosystem management, conservation and potential restoration projects. The decline in fish populations, fish size, and diversity of populations is directly linked to the declining health of the reef; similarly, the decline in fish is directly linked to the health of the community. The livelihood of the Vezo people of Ifaty is dependent on the reef and as the reef continues to decline in productivity, so will the people of Ifaty’s culture of subsistence living. ICDPs exist because conservation and development cannot be disconnected; especially in communities like Ifaty where local livelihoods and their development are dependent on an ecosystem that drastically needs conservation measures to ensure present and future productivity. It is precisely the interdependency of conservation and development that makes these projects so complicated; at what point do you start? The cyclical nature almost demands starting at all points. If we gradually put one mechanism in place at a time, such as an unofficial marine protected area governed under local customary law, implementing an environmental education curriculum in local schools, and encouraging the idea of alternative livelihoods, these efforts that complement one another towards the common objective of reef conservation and community development. Women are often an underutilized community resource in development programs. It is for this reason that Reef Doctor has taken steps to encourage the women of Ifaty to organize into an association oriented towards income generating activities. Women’s associations encourage a sense of ownership, self-sufficiency, and solidarity among members that reinforces members’ self-confidence and faith in themselves and collective efforts. The hope is that the creation of a women’s association in Ifaty can serve as a sort of catalyst in the community towards alternative livelihood projects. The question remains as to whether projects will be alternative or merely supplemental livelihoods in a society with no traditional savings scheme, a low level of education, and a persistent level of poverty

An Exploration into the Use of Manipulatives to Develop Abstract Reasoning in an Introductory Science Course

Classical physics has a long history of using demonstrations and experiments to develop ideas in introductory courses. The purpose of this exploration is to examine the effectiveness of a desk-top activity for helping students develop abstract reasoning. In the pilot exploration, students in three laboratory sections of a single physics course were given different supplemental instructions on development of free body diagrams: standard instruction, system schemas, and a new approach building physical models of those schemas. Students using the physical models avoided common errors made by the other two groups. More importantly, their discussion with a student researcher about developing diagrams showed a deeper understanding of the concepts and less guessing than responses of the control groups. In a subsequent use of this activity with an entire class, similar positive results were found for free body diagrams although the activity did not have an impact on related topics in the course

Domestic well vulnerability to drought duration and unsustainable groundwater management in California's Central Valley

Millions of Californians access drinking water via domestic wells, which are vulnerable to drought and unsustainable groundwater management. Groundwater overdraft and the possibility of longer drought duration under climate change threatens domestic well reliability, yet we lack tools to assess the impact of such events. Here, we leverage 943 469 well completion reports and 20 years of groundwater elevation data to develop a spatially-explicit domestic well failure model covering California's Central Valley. Our model successfully reproduces the spatial distribution of observed domestic well failures during the severe 2012-2016 drought (n = 2027). Next, the impact of longer drought duration (5-8 years) on domestic well failure is evaluated, indicating that if the 2012-2016 drought would have continued into a 6 to 8 year long drought, a total of 4037-5460 to 6538-8056 wells would fail. The same drought duration scenarios with an intervening wet winter in 2017 lead to an average of 498 and 738 fewer well failures. Additionally, we map vulnerable wells at high failure risk and find that they align with clusters of predicted well failures. Lastly, we evaluate how the timing and implementation of different projected groundwater management regimes impact groundwater levels and thus domestic well failure. When historic overdraft persists until 2040, domestic well failures range from 5966 to 10 466 (depending on the historic period considered). When sustainability is achieved progressively between 2020 and 2040, well failures range from 3677 to 6943, and from 1516 to 2513 when groundwater is not allowed to decline after 2020

Comparison Tests of the Column Coefficient and the Gravity Coefficient Models

This study presents a comparison of the 1947, 1958, 1963, 1970, and 1980 regional outputs estimated using the column coefficient and gravity coefficient models. An evaluation is made of the accuracy of the two models in estimating 1947, 1958, and 1963 outputs. A detailed review of the industrial and regional estimation errors is provided by the authors, supplemented by appendix tables showing the errors for each of 10 industries in each of 9 regions