36,353 research outputs found
Microstructure and properties of duplex coatings on magnesium alloy
No full textThe duplex Ti cold spray + MAO coatings were deposited on the Mg alloy substrates using combined cold spray and micro arc oxidation (MAO). The microstructure, mechanical property and corrosion resistance of the duplex coatings were investigated compared with the MAO coated Mg alloy substrate. Results indicate that the Ti cold spray coating with 130 mu m showed an obvious boundary between the Mg substrate, and the TiO2 phase was formed by MAO on the top coating. The duplex coating showed a little coarse and porous structure, which resulted in low mechanical property and wear resistance compared with the MAO treated Mg substrate. However, it showed an excellent corrosion resistance due to the difference of chemical stability for the coatings. Furthermore, this duplex coating might be very useful for improving the photocatalytic ability of titania due to its markedly increasing specific area
Special issue: Process safety in times of a pandemic
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Safety and Security Scienc
Distributed human computation framework for linked data co-reference resolution
No full textDistributed Human Computation (DHC) is a technique used to solve computational problems by incorporating the collaborative effort of a large number of humans. It is also a solution to AI-complete problems such as natural language processing. The Semantic Web with its root in AI is envisioned to be a decentralised world-wide information space for sharing machine-readable data with minimal integration costs. There are many research problems in the Semantic Web that are considered as AI-complete problems. An example is co-reference resolution, which involves determining whether different URIs refer to the same entity. This is considered to be a significant hurdle to overcome in the realisation of large-scale Semantic Web applications. In this paper, we propose a framework for building a DHC system on top of the Linked Data Cloud to solve various computational problems. To demonstrate the concept, we are focusing on handling the co-reference resolution in the Semantic Web when integrating distributed datasets. The traditional way to solve this problem is to design machine-learning algorithms. However, they are often computationally expensive, error-prone and do not scale. We designed a DHC system named iamResearcher, which solves the scientific publication author identity co-reference problem when integrating distributed bibliographic datasets. In our system, we aggregated 6 million bibliographic data from various publication repositories. Users can sign up to the system to audit and align their own publications, thus solving the co-reference problem in a distributed manner. The aggregated results are published to the Linked Data Cloud
Intersystem soft handover for converged DVB-H and UMTS networks
No full textDigital video broadcasting for handhelds (DVB-H) is the standard for broadcasting Internet Protocol (IP) data services to mobile portable devices. To provide interactive services for DVB-H, the Universal Mobile Telecommunications System (UMTS) can be used as a terrestrial interaction channel for the unidirectional DVB-H network. The converged DVB-H and UMTS network can be used to address the congestion problems due to the limited multimedia channel accesses of the UMTS network. In the converged network, intersystem soft handover between DVB-H and UMTS is needed for an optimum radio resource allocation, which reduces network operation cost while providing the required quality of service. This paper deals with the intersystem soft handover between DVB-H and UMTS in such a converged network. The converged network structure is presented. A novel soft handover scheme is proposed and evaluated. After considering the network operation cost, the performance tradeoff between the network quality of service and the network operation cost for the intersystem soft handover in the converged network is modeled using a stochastic tree and analyzed using a numerical simulation. The results show that the proposed algorithm is feasible and has the potential to be used for implementation in the real environment
Beyond interfaces: A usability study of Chinese journal databases
No full textA presentation at the Council on East Asian Libraries (CEAL) annual meeting in Boston, MA on March 21, 2007
Rose Galaida and the Central China Relief Records, 1946: Discovery, Investigation, and Implications
No full textThe materials in the Central China Relief Records (CCRR) collection provide a window to the experiences of Rose Galaida in Hubei. The collection consists of about 100 documents totaling over 300 pages (excluding duplicate copies) and 5 photographs.Peer reviewedPublished in the Journal of East Asian Libraries and available from the journal at: https://scholarsarchive.byu.edu/jeal/vol2011/iss153/
Breaking New Ground in East Asia Library History
No full textReview of Peter X. Zhou. Collecting Asia: East Asian Libraries in North America (2010).Published in H-Net Reviews in the Humanities and Social Sciences and available at: http://www.h-net.org/reviews/showrev.php?id=32231March 201
Investigation of the initial stage of Mandarin tones acquisiton by Australian university students
No full textOne step preparation of pure tau-MnAl phase with high magnetization using strip casting method
No full textFerromagnetic phase of Mn-Al exhibits great potential in the rare-earth free permanent magnetic materials due to its high magnetocrystalline anisotropy, high magnetization, high Curie temperature and low cost. In this work, the strip casting technique was applied to prepare MnAl magnetic phase. X-ray diffraction and energy dispersive X-ray analyses indicate that the as-prepared Mn54Al46 strip sample consists of pure tau-MnAl magnetic phase. It is found that the composition of Mn54Al46 is suitable to prepare tau-MnAl phase during the strip casting process. The Mn54Al46 strip sample synthesized through the strip casting exhibits a fairly high magnetization of 114 emu/g under a field of 5 T, while the coercivity of iHc = 2.8 kOe, magnetization of M-5T = 63.9 emu/g at room temperature can be obtained for Mn54Al46 powder sample. This preparation method can produce a large amount of tau-phase MnAl alloy and promote mass industrialized production. (C) 2017 Author(s)
Epidemiology and burden of soil-transmitted helminth infections among school-aged Bulang children in Yunnan province, People's Republic of China
No full textBackground: The three most common soil-transmitted helminths are Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), and Ancylostoma duodenale and Necator americanus (hookworms). Collectively, they infect around 1 billion people and put approximately 5 billion people at risk of infection worldwide. Strongyloides stercoralis is a less common soil-transmitted helminth than the species mentioned above, but still significant from a public health perspective. The global prevalence of S. stercoralis is estimated to be 30-100 million. Populations most affected by these parasitic worms are often impoverished, living on less than US$ 2 per day, and have poor sanitation facilities and hygiene habits. Despite the low prevalence levels of soil-transmitted helminth infections observed on a national level in the People’s Republic of China (P.R. China), hotspots of these infections, particularly within ethnic minority groups residing in rural areas, still exist.
Single-species infections with the common soil-transmitted helminths can cause symptoms ranging from abdominal pain to anaemia, and impaired development of cognitive abilities. For S. stercoralis infections, symptoms such as severe abdominal pain and blood in the stool have been reported. Due to the chronic and subtle nature of most morbidities commonly associated with soil-transmitted helminthiasis, it is difficult to assess the true burden due to these infections.
Objectives: The goal guiding this Ph.D. project was to deepen the understanding of the epidemiology and burden of soil-transmitted helminthiasis among school-aged children from the Bulang ethnic minority group in P.R. China. The following objectives were pursued: (i) to evaluate the feasibility of deploying different tools for the assessment of physical fitness in soil-transmitted helminth-endemic settings; (ii) to monitor changes in physical fitness, strength and anthropometric measurements over a six-month period among treated children and their untreated peers; (iii) to predict and visualize the change in physical fitness of school-aged children due to soil-transmitted helminth infections over a 1-month period across P.R. China; (iv) to assess the efficacy of triple-dose albendazole and study soil-transmitted helminth re-infection patterns after deworming; and (v) to estimate the odds of re-infection with soil-transmitted helminths for different natural nutritional statuses and types of nutritional supplementation.
Methods: For the field studies, parasitological examination of stool samples was performed. The Kato-Katz technique was used to identify the eggs of A. lumbricoides, hookworm, T. trichiura and other helminths, while the Baermann technique was used to identify the larvae of S. stercoralis. In addition, each stool sample was visually inspected for Taenia spp. proglottids. Physical fitness was estimated with the 20-m shuttle run test and physical strength was assessed with the grip strength and standing broad jump tests. Anthropometric measurements, including body height and weight and sum of skinfolds, and haemoglobin level were also recorded. Physical fitness and strength scores, anthropometric measurements, and haemoglobin level were expressed as means, and compared among children of distinct soil-transmitted helminth infection status and intensity. For the prediction and visualization exercise, the change in physical fitness over 1 month across P.R. China was predicted over a smooth surface of soil-transmitted helminth risk. Maps, with lower and upper boundaries of the predicted values as well as population-adjusted estimates, were further created. Finally, for the systematic review, the odds of re-infection with soil-transmitted helminths for different natural nutritional statuses and types of nutritional supplementation were estimated and qualitative content analysis was conducted for all studies included in the review.
Results: In a cross-sectional survey, the maximum aerobic capacity in 1 min of exhaustive exercise (VO2 max estimate) of T. trichiura-infected children was 1.9 ml kg-1 min-1 lower than that of their non-infected counterparts (P=0.01). Until exhaustion, T. trichiura-infected children had completed six 20-m laps less (P<0.01). No significant association between anthropometric indicators and infection with any soil-transmitted helminth species could be established.
In a randomised controlled trial, which investigated the effects of triple-dose albendazole on physical fitness of school-aged children, baseline prevalences of T. trichiura, A. lumbricoides, hookworm, and S. stercoralis were 94.5%, 93.3%, 61.3%, and 3.1% respectively, with more than half harboring triple-species infections. During the course of the trial, rapid re-infection with A. lumbricoides was observed and low cure rate was achieved with T. trichiura infections. Children receiving triple-dose albendazole scored slightly higher values in physical fitness and strength scores, anthropometric measurements, and haemoglobin level than placebo recipients, but the difference lacked statistical significance. The increase in VO2 max estimate from baseline was 1.6 ml kg-1 min-1 (P=0.02) less and the increase in the number of 20-m laps completed from baseline was five 20-m laps (P=0.04) less for T. trichiura-infected children compared to their non-infected peers. In addition, children with low infection intensity of T. trichiura and hookworm had consistently more increase in the VO2 max estimate from baseline than their peers with high infection intensity of all soil-transmitted helminths (range: 1.9-2.1 ml kg-1 min-1; all P <0.05).
In the systematic review, multi-micronutrients seemed to have the clearest effect with regards to lowering re-infection rates and intensity of soil-transmitted helminths, whereas consumption of zinc or vitamin A alone might have a negative impact on these two outcomes measures. With regards to the natural nutrition status of the host, the general trend observed was that individuals with poor nutrition status suffered higher re-infection rates and intensities when compared to their well-nourished peers. Overall, only fifteen studies met our inclusion criteria and majority of them were of low quality.
Conclusions/significance: The negative associations observed between T. trichiura infections and physical fitness among school-aged Bulang children in Yunnan suggests that the current burden estimate of soil-transmitted helminth infections, in particular T. trichiura infections, might be underestimated and there are still subtle and hidden morbidities to be quantified. A paradigm shift is needed to further understand the burden of soil-transmitted helminth infections as the presence of co-infections and co-morbidities add layers of complexity to the task. Finally, the epidemiological findings on soil-transmitted helminthiasis from this thesis highlight that a national soil-transmitted helminth control programme is overdue and urgently needed as P.R. China further develops into a global powerhouse. With many of their rural communities starting to have their hands on the first rung of the development ladder, P.R. China seems to be in a good position to set a leading example on how to control and eliminate soil-transmitted helminthiasis, and possibly other neglected tropical diseases, for developing countries around the world
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