Comparative analysis of phytochemicals and polar metabolites from colored sweet potato (Ipomoea batatas L.) tubers

Food Science and Biotechnology - We determined the phytochemical diversity, including carotenoids, flavonoids, anthocyanins, and phenolic acids, in sweet potatoes (Ipomoea batatas L.) with...     

Hyperendemicity associated with increased dengue burden

Over 105 million dengue infections are estimated to occur annually. Understanding the disease dynamics of dengue is often difficult due to multiple strains circulating within a population. Interactions between dengue serotype dynamics may result in complex cross-immunity dynamics at the population level and create difficulties in terms of formulating intervention strategies for the disease. In this study, a nationally representative 16-year time series with over 43 000 serotyped dengue infections was used to infer the long-run effects of between and within strain interactions and their impacts on past outbreaks. We used a novel identification strategy incorporating sign-identified Bayesian vector autoregressions, using structural impulse responses, historical decompositions and counterfactual analysis to conduct inference on dengue dynamics post-estimation. We found that on the population level: (i) across-serotype interactions on the population level were highly persistent, with a one time increase in any other serotype associated with long run decreases in the serotype of interest (range: 0.5–2.5 years) and (ii) over 38.7% of dengue cases of any serotype were associated with across-serotype interactions. The findings in this paper will substantially impact public health policy interventions with respect to dengue.     

Synthesis of sub-micron nickel particles coated onto aluminum powders via a modified polyol process

Aluminum is commonly used as a fuel additive for propellants. The main limitations to its use lie in comparatively slow ignition and oxidation/combustion kinetics. Combustion performance of aluminized propellants can be improved through the use of Ni-coated Al particles. Sub-micron to nano-sized particles, with their increased reactivity, also improve combustion performance. Hence, in these contexts, fine Ni particles coated onto commercially available micron-sized Al powders using a modified polyol process were synthesized and evaluated. Ni-coated Al powders of various compositions produced by this method showed significant improvement in oxidation kinetics compared to untreated Al powders. The onset oxidation temperatures for the Ni-coated Al powders were found to be significantly reduced compared to pure untreated Al.     

Development of a method of evaluating an inventory of fission products for a pebble bed reactor

The design of the high temperature gas-cooled reactor (HTGR) has evolved and the relevant safety requirements have been defined; accordingly, the source term to be used as the basis for licensing must also be developed. However, analysis of the source term in the HTGR has not been adequately investigated and there has not been definite improvement in this respect. Because radioactivity in normal operation must be well understood, the purpose of this study is to establish a method for activity evaluation by the code combination MCNP-ORIGEN-MONTEBURNS-MOTEX. The sophisticated method, which constructs the HTR-10 core by using the unit lattice of a hexagonal prism, is developed for core modeling. The MCNP modeling is used to simulate the generation of fission products with an increase of burnup, and ORIGEN is utilized for depletion calculation of each fission product. Continuous fuel management is divided into five discrete periods for the feeding and discharging of fuel pebbles. MONTEBURNS is used for discrete fuel management. In short, this work by aid from MOTEX traces 41 isotope nuclides, the results of which seem highly probable. In addition, the inventory of actinides at the end of each cycle is also investigated. It would be informative when the waste management of spent fuel of HTGRs would be taken into account. This article lays the foundation for future work on the analysis of the source term in HTGRs and will hopefully serve as a platform from which the safety assessment of radioactive material release during accidents can be undertaken in future.     

Experimental study of post-dryout with R-134a upward flow in smooth tube and rifled tubes

A study of post-dryout heat transfer was performed with a directed heated smooth tube and rifled tubes using vertical R-134a up-flow to investigate the heat transfer characteristics in the post-dryout region. Three types of rifled tube having different rib height and width were used to examine the effects of rib geometry and compare with the smooth tube, using a mass flux of 70–800 kg/m² s and a pressure of 13–24 bar (corresponding to an approximate water pressure of 80–140 bar). Wall temperature distribution in all tubes was strongly dependent on pressure and mass flux. Wall temperatures of the rifled tubes in the post-dryout region were much lower than for the smooth tube at same conditions. This was attributed to swirl flow caused by the rib. Thus, the thermal non-equilibrium, which is usually present in the post-dryout region, was lowered. The empirical correlation of heat transfer in the smooth tube of the post-dryout region was obtained. The heat transfer correlation for rifled tubes was also obtained as a function of rib height and width with the modification of the smooth tube correlation.     

Conventional and decentralized urban stormwater management: A comparison through case studies of Singapore and Berlin,Germany

Urban stormwater runoff is both a significant pollution source and a potentially valuable resource. This study compares stormwater management in two cities: Singapore and Berlin, Germany. In comparing the strategies for stormwater management, we illustrate how differences in geography (e.g., land and water availability), urban infrastructure, regulatory regimes, legislation and intensives between the two cities have led to different solutions for stormwater management. Singapore, faced with a serious issue of water scarcity, has placed an increasing emphasis on stormwater management through developing a comprehensive network of drains and canals, mainly with the aim of controlling flooding and potable water supply. In contrast, in Berlin, concerns for the protection of surface water quality and non-potable water supply in the urban areas have resulted in a shift in management goals towards a low impact solution based on source control. The cost analysis indicated that the decentralized rainwater harvesting as practiced in Berlin leads to a higher economic efficiency where potable water can be substituted by stormwater, compared to the centralized drainage system in Singapore. Additionally, green roofs result in energy savings by serving as mitigation strategies against the effect of urban heat islands and global warming. In the near future, it is envisioned that a combination of both conventional and decentralized urban stormwater management will prove to be the most practical solution for most cities.     

Low distortion speech enhancement

An innovative approach to speech enhancement is illustrated which minimises distortion to the underlying speech during the noise-reduction process. The key to this approach lies in the identification of whether the additive noise for a particular frequency component is constructive or destructive. Once this can be identified both multiplicative and subtractive filters can be derived using the minimum mean-square error criterion. The optimal combination of the proposed multiplicative and subtractive filter is also shown