873 research outputs found

    Learning Analytics in Collaborative Online Lab Environments: A Systematic Scoping Review

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    With the increase in online education arises the challenge of replicating physical laboratories and teamwork online. This poster presents a brief overview of a scoping review of the current research within the area of learning analytics and collaboration in online laboratory environments, including results on the used learning analytics method. A gap of knowledge in the current research where there is a lack of research addressing this topic has been identified. This calls for the need of further research within this area.publishedVersio

    Kinetics, Activation Parameters, and Mechanism of the Acid Hydrolysis of tert-Butyl Acetate in Aqueous DMSO

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    The rate of the acid-catalysed hydrolysis of tert-butyl acetate was found to decrease pronouncly in the presence of increasing amounts of DMSO. The observed activation energy decreased progressively with increasing DMSO content of the medium and the change was attributed to a gradual interconversion of the two concurrent and competing reaction mechanisms AALl and AAc2. The overall reaction rate was analysed theoretically as two individual rate constants corresponding to the respective mechanisms. The percentage contribution of each mechanism was then estimated and found to be concordant with the values determined experimentally by others using 180 tracer technique. The proportion of the AALl mechanism was found to increase both with increasing temperature and decreasing DMSO content. The relative abundance of the transition state belonging to each of the involved mechanisms was discussed in the light of the solvating power of the binary DMSO-H20 solvent system. The effect of the molar concentration of water as well as the dielectric constant of the medium on the reaction kinetics was studied. The thermodynamic parameters of activation showed strong dependence on solvent composition and their values were determined by the relative contributions of the two mechanistic routes of the reaction

    A Review of the Potential Health Benefits of Low Alcohol and Alcohol-Free Beer: Effects of Ingredients and Craft Brewing Processes on Potentially Bioactive Metabolites

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    Beer is a beverage of significant historical and cultural importance. Interest in the potential health effects of alcoholic beverages has largely focused on wine; however, there are a number of potentially beneficial bioactives that beer may contain that warrant further investigation. The challenge of considering any potential health benefits of beer are restricted by the negative consequences of its alcohol and energy content. There is potential to enhance the bioactive qualities of beer whilst reducing the alcohol and energy content through novel brewing approaches often used in craft brewing, in terms of ingredients, brewing methods and type of fermentation. Consumer demand to produce a greater variety of beer types, including alcohol-free beers, may also help to increase the number of beers which may have greater potential to improve health, with lower levels of alcohol, while still being tasty products. As low alcohol, prebiotic and bioactive containing beers are developed, it is important that their potential health benefits and risks are fully assessed

    Effect of NaBH4 on properties of nanoscale zero-valent iron and its catalytic activity for reduction of p-nitrophenol

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    International audienceThe reduction of p-nitrophenol (p-NP) to p-aminophenol (p-AP) by nanoscale zero-valent iron (NZVI)/NaBH4 system in an oxygen environment was studied by means of liquid chromatography, spectroscopy (vibration and X-ray photoelectron), solid analyses (transmission electron microscopy and X-ray diffraction) and density functional theory (DFT) calculations. Addition of NaBH4 into NZVI suspension showed the disintegration of NZVI (60-100 nm), resulting in the formation of much smaller particles (15-40 nm) due to the chemical etching of outermost surfaces (i.e., magnetite). Interestingly, complete reduction of p-NP and high conversion efficiency of p-AP (> 98%) were observed in NZVI/NaBH4 system even after four recycling which is quite comparable with widely used noble metallic catalysts. Surface analysis confirmed that NaBH4 can prevent the oxidation of NZVI surface, leading to the continuous reduction of p-NP in oxygen environments. Experimental results and DFT calculations suggested that not only the formation of smaller NZVI but also thermodynamic preferences for reduction of p-NP on outermost surfaces of NZVI (i.e. magnetite) may significantly affect the reduction process of p-NP in NZVI/NaBH4 system. These novel findings can promote the development of new NZVI technologies which can be used for wastewater reductive treatment in oxygen environment

    Predictive ADRC Control Using LMI

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    On recent times Active Disturbance Rejection Control has drawn both the attention of industrial and scientific community due to its capability to handle uncertainties and nonlinearities without using an explicit model of the system; on this paper a modification of the ADRC algorithm is presented, first an Extended State Predictor is calculated and later, a controller is built using the LMI approach, the proposal is evaluated through simulations on the Cayley-Rodriguez representation of the Monoaxial satellit

    Oxidant selection to treat an aged PAH contaminated soil by in situ chemical oxidation.

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    International audienceThis work is a part of the OXYSOL project aiming at the conception of a global treatment pathway including In Situ Chemical Oxidation to clean up soils of former metallurgical sites. It deals with the selection of the most adapted oxidants. Batch experiments were performed with aged contaminated soil samples of a former steel-making plant to degrade the 16 US EPA PAHs. In this research, hydrogen peroxide, modified Fenton's reaction, potassium permanganate, sodium percarbonate and sodium persulfate were compared at high and moderate doses. Hydrogen peroxide, modified Fenton's reagent, percarbonate and activated persulfate led to a maximum degradation ratio of 45%. A higher ratio (70%) was obtained with a high dose of permanganate. Except for permanganate, increasing oxidant dose did not improve degradation rates, especially with radical-based oxidative systems probably due to radical scavenging. Oxidant doses had an effect on pH that drastically increased or dropped in some cases, which was a drawback. Permanganate efficacy was mainly assigned to its persistence. In all cases, the low availability of PAHs, partly sequestrated in the aged soil, was identified as the most limiting factor for degradation performance. Oxidants were ranked according to their efficiency for PAH oxidation in soils. Efficiency was not correlated to the doses

    Sorption of nalidixic acid onto micrometric and nanometric magnetites: experimental study and modeling

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    International audienceThe sorption of nalidixic acid (NA) was studied onto three kinds of magnetite characterized by different particle sizes (from micrometric to nanometric) and surface properties. Experiments were performed under static batch and dynamic flow conditions. Obtained results indicate that kinetics and extent of sorption was strongly affected by the particle size of tested magnetites. Ionic strength effect was less significant suggesting that aggregation state of the magnetite particles did not affect the sorption. During kinetic sorption experiments, apparent rate constant normalized to solid mass was faster for nanosized magnetite while an opposite trend was observed for the surface area-normalized rate constants. Infrared data suggested the possibility of similar surface interactions on both microsized and nanosized magnetites. Transport of NA in magnetite-packed column was found associated to the instantaneous sorption without any significant effect of kinetic limitation. Breakthrough curves (BC) and sorption extent in columns were calculated by using Thomas, Yan and Yoon-Nelson models. Sorption capacities predicted by Thomas or Yan model were in good agreement with that determined by integrating total area above BC. However, Thomas model failed particularly to predict an accurate concentration at lower and higher time points of the BC. These findings have strong implications in relation to the transport and removal of environmental pollutants in natural and engineered systems

    Adaptation strategies in transnational education: a case study of an Australian Master of Health Administration Course offered to Chinese managers

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    Background: Management decisions in health influence patient care outcomes; however, health management development courses in China are rare. This study aims to document and evaluate a transnational Master of Health Administration (MHA) course launched in 2000 for the benefit of Chinese health managers. Methods: A case study of the MHA program jointly run by an Australian university and a Chinese Medical University was conducted. We reviewed the development of the MHA course through a document analysis (key events recorded in achieves, minutes, and audits) followed by reflection (by two course coordinators), extracting key themes related to adaptative strategies. We then conducted a questionnaire survey of 139 graduates seeking their views on relevance, satisfaction and challenges associated with each subject within the course, the relevance of key management skills (as determined by the Australasian College of Health Service Management competency framework), and the impact of the course on their personal career trajectories. Chi-square tests identified differences in the responses by age, gender, pre-training position, and current workplace. Results: The curriculum pedagogy followed the principles of practice-based reflective learning. Research findings and student feedback shaped the curriculum design and subject content, to enhance management practices of the students. Survey participants expressed high levels of satisfaction and confirmed the relevance of all study subjects. Two subjects, health economics and data management, were perceived as being the most challenging. Of the ten management skills we assessed, relatively low self-rated confidence was found in “strategic thinking” and “planning”. Younger and less experienced graduates were more likely to report learning challenges (p < 0.05). Frontline managers were least likely to obtain promotion by changing employers (χ2 = 6.02, p < 0.05) or being seconded to another position (χ2 = 9.41, p < 0.01). Conclusions: This case study illustrates the suitability of cross-country partnerships in health management training, which offers opportunities for managers to systematically explore and acquire a comprehensive set of management skills applicable to their career needs. Opportunities for developing training aligned to career development opportunities are critical for attracting and developing a competent and well-prepared health service management workforce in China

    Ecological Agro-ecosystem Sustainable Development in Relationship to Other Sectors in the Economic System, and Human Ecological Footprint and Imprint☆

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    Abstract Sustainable agriculture is the major economic sector (i.e. about 30% of Global economy) with the industrial and trading system in the world's economy. It is important to understand why the sustainable development is very important to the point of view of improving of human life and reducing the poverty. Additionally, we need to sustain our natural resources to be replenished and continue support our human population growth that is continued to increase in alarming rate rather than development, which is in a slow rate that does not meet the demands. This paper is to discuss the importance of global agro-ecosystems, to support humans' needs for feeding and continue their lives in a healthy and sustainable life and to function within the society. In addition, the paper will show the availability of the agriculture natural resources in terms of global ecological biological capacities in hectares and the trends in using these resources in terms of an ecological footprint in hectares. Additionally, we study the term of ecological human imprint in relation to the agro-ecosystem as suggested by Shakir Hanna et al., 2014 . Further the paper will address the impacts of agro-ecosystem on global economy and, further discuss the impacts of human technological advances on agro-ecosystems ecologically, economically, and social importance. Our results show that the global population will be 10.50 billion people in 2050 (i.e. 1.1% the current population growth). The available global cropped land is 2.36 billion global hectares in 2008.The question is the Earth able to provide food and other agricultural products to support the healthy living of all human beings in year 2050 at the current growth rate? The paper is discussing these concerns
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