589 research outputs found
A user-centred collective system design approach for Smart Product-Service Systems:A case study on fitness product design
Emerging technologies have significantly contributed to the evolution of traditional product-service systems (PSS) into smart PSS. This transformation demands a fresh perspective and a more inventive design approach. In response, this study proposes a new User-Centred Collective System Design (CSD) framework and process for Smart PSS design, aiming to enhance stakeholder engagement during the entire design process, thus promoting highly effective and creative design solutions. A case study, titled ‘Next-G Smart Fitness PSS Design’, was carried out to test and implement this approach, contrasting the results of the CSD method with a designer-centred method. The outcomes showed a marked improvement in product novelty and user desirability of the design outcomes when using the proposed design framework. The proposed CSD framework could offer beneficial insights and user-centric viewpoints for practitioners dealing with complex challenges linked to smart PSS design
Laser additive manufacturing of niobium silicide-based composites
Niobium silicide-based composites, in the application of gas turbine blades, promise significant efficiency improvements compared to current Ni-based alloys. The higher temperature capability would allow the engine to run at a higher temperature than that of current alloys, increasing engine efficiency. Nb-Si based composites possess a lower density, due to the presence of ceramic phases such as Nb5Si3 and/or Nb3Si. This would reduce the weight of the rotating blades. However, improvements in certain properties, such as ductility, room temperature toughness and oxidation resistance are needed. The alloy must also be cost effective to manufacture if niobium silicide systems are to reach their full potential.
This study focuses on the manufacturability aspect of the powder feeding laser additive manufacturing (LAM) process to engineering Nb-Si based alloy samples. A schematic drawing of LAM system is shown in Figure 1. In LAM process, CAD models of the components are constructed and sliced layer by layer for laser multilayer cladding, which directly forms the component shapes. LAM has the advantage of forming near-net shapes without the use of expensive cores and moulds for the reactive Nb-Si melt. Fine microstructure and even chemical composition distribution with reduced macro-segregation are obtained. With the use of power feeding system, new Nb-Si based alloys are LAMed with varying Ti, Si, Cr, Al, Hf, V concentrations. Microstructures and mechanical properties of the LAMed new alloys will be presented, the relationship between mechanical property, alloy chemistry and process variable will be analyzed and the challenges in powder feeding laser additive manufacturing of Nb-Si based composites will be reported.
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The Viscoelasticity Model of Corn Straw under the Different Moisture Contents
Viscoelastic model of corn straw, based on different moisture contents, is set up to characterise the deformation through three-point bending test. The model contains a linear elastic element, a damping element, and a nonlinear elastic element. The parameters of the model are determined according to the features of three-point bending test curve and characteristic of the model. The relationships between mechanical properties, energy absorption behavior of corn stalk, and moisture content have been, respectively, analysed. And regression analysis and curve fitting have been conducted based on various parameters and moisture contents with Matlab. These parameters provide the basis for straw crushing equipment design
Effects of manganese-excess on CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, carbohydrates and photosynthetic electron transport of leaves, and antioxidant systems of leaves and roots in Citrus grandis seedlings
<p>Abstract</p> <p>Background</p> <p>Very little is known about the effects of manganese (Mn)-excess on citrus photosynthesis and antioxidant systems. Seedlings of sour pummelo (<it>Citrus grandis</it>) were irrigated for 17 weeks with nutrient solution containing 2 μM (control) or 500 μM (excess) MnSO<sub>4</sub>. The objective of this study were to understand the mechanisms by which Mn-excess leads to a decrease in CO<sub>2 </sub>assimilation and to test the hypothesis that Mn-induced changes in antioxidant systems differ between roots and leaves.</p> <p>Results</p> <p>Mn-excess decreased CO<sub>2 </sub>assimilation and stomatal conductance, increased intercellular CO<sub>2 </sub>concentration, but did not affect chlorophyll (Chl) level. Both initial and total ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity in Mn-excess leaves decreased to a lesser extent than CO<sub>2 </sub>assimilation. Contents of glucose, fructose, starch and total nonstructural carbohydrates did not differ between Mn-excess leaves and controls, while sucrose content was higher in the former. Chl a fluorescence (OJIP) transients from Mn-excess leaves showed increased O-step and decreased P-step, accompanied by positive L- and K-bands. Mn-excess decreased maximum quantum yield of primary photochemistry (F<sub>v</sub>/F<sub>m</sub>) and total performance index (PI<sub>tot,abs</sub>), but increased relative variable fluorescence at I-steps (V<sub>I</sub>) and energy dissipation. On a protein basis, Mn-excess leaves displayed higher activities of monodehydroascorbate reductase (MDAR), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (GPX) and contents of antioxidants, similar ascorbate peroxidase (APX) activities and lower dehydroascorbate reductase (DHAR) activities; while Mn-excess roots had similar or lower activities of antioxidant enzymes and contents of antioxidants. Mn-excess did not affect malondialdehyde (MDA) content of roots and leaves.</p> <p>Conclusions</p> <p>Mn-excess impaired the whole photosynthetic electron transport chain from the donor side of photosystem II (PSII) up to the reduction of end acceptors of photosystem I (PSI), thus limiting the production of reducing equivalents, and hence the rate of CO<sub>2 </sub>assimilation. Both the energy dissipation and the antioxidant systems were enhanced in Mn-excess leaves, while the antioxidant systems in Mn-excess roots were not up-regulated, but still remained high activity. The antioxidant systems in Mn-excess roots and leaves provided sufficient protection to them against oxidative damage.</p
CO2 assimilation, ribulose-1,5-bisphosphate carboxylase/oxygenase, carbohydrates and photosynthetic electron transport probed by the JIP-test, of tea leaves in response to phosphorus supply
<p>Abstract</p> <p>Background</p> <p>Although the effects of P deficiency on tea (<it>Camellia sinensis </it>(L.) O. Kuntze) growth, P uptake and utilization as well as leaf gas exchange and Chl a fluorescence have been investigated, very little is known about the effects of P deficiency on photosynthetic electron transport, photosynthetic enzymes and carbohydrates of tea leaves. In this study, own-rooted 10-month-old tea trees were supplied three times weekly for 17 weeks with 500 mL of nutrient solution at a P concentration of 0, 40, 80, 160, 400 or 1000 μM. This objective of this study was to determine how P deficiency affects CO<sub>2 </sub>assimilation, Rubisco, carbohydrates and photosynthetic electron transport in tea leaves to understand the mechanism by which P deficiency leads to a decrease in CO<sub>2 </sub>assimilation.</p> <p>Results</p> <p>Both root and shoot dry weight increased as P supply increased from 0 to 160 μM, then remained unchanged. P-deficient leaves from 0 to 80 μM P-treated trees showed decreased CO<sub>2 </sub>assimilation and stomatal conductance, but increased intercellular CO<sub>2 </sub>concentration. Both initial and total Rubisco activity, contents of Chl and total soluble protein in P-deficient leaves decreased to a lesser extent than CO<sub>2 </sub>assimilation. Contents of sucrose and starch were decreased in P-deficient leaves, whereas contents of glucose and fructose did not change significantly except for a significant increase in the lowest P leaves. OJIP transients from P-deficient leaves displayed a rise at the O-step and a depression at the P-step, accompanied by two new steps at about 150 μs (L-step) and at about 300 μs (K-step). RC/CS<sub>o</sub>, TR<sub>o</sub>/ABS (or F<sub>v</sub>/F<sub>m</sub>), ET<sub>o</sub>/ABS, RE<sub>o</sub>/ABS, maximum amplitude of IP phase, PI<sub>abs </sub>and PI<sub>tot, abs </sub>were decreased in P-deficient leaves, while V<sub>J</sub>, V<sub>I </sub>and dissipated energy were increased.</p> <p>Conclusion</p> <p>P deficiency decreased photosynthetic electron transport capacity by impairing the whole electron transport chain from the PSII donor side up to the PSI, thus decreasing ATP content which limits RuBP regeneration, and hence, the rate of CO<sub>2 </sub>assimilation. Energy dissipation is enhanced to protect P-deficient leaves from photo-oxidative damage in high light.</p
Expression TGM2 and BNIP3 have prognostic significance in laryngeal cancer patients receiving surgery and postoperative radiotherapy: A retrospective study
Can Overconfidence be Debiased by Low-Probability/High-Consequence Events?
During the first half of 2008, China suffered three natural disasters: a heavy snow storm, an outbreak of hand-foot-mouth disease, and a severe earthquake. The aim of the present study is to explore how low-probability/high-consequence events influence overconfidence. In Study 1, opportunity samples were obtained by recruiting residents in three different types of disaster-hit areas to answer a peer-comparison probability judgment questionnaire about 1 month after the corresponding disaster occurred. The performance of 539 participants in disaster-hit areas was compared with that of 142 residents in a nondisaster area. The findings indicate that residents in disaster-hit areas were less overconfident than those in the nondisaster area on both positive and negative events. In Study 2, we surveyed a total of 336 quake-victims 4 and 11 months after the earthquake to examine whether the impact of disasters on overconfidence would decay with time. The resulting data indicate that the disaster victims became more overconfident as time elapsed. The overall findings suggest that low-probability/high-consequence events could make people less overconfident and more rational and seem to serve as a function of debiasing.</p
Natural variation in a molybdate transporter controls grain molybdenum concentration in rice
© 2018 The Authors. New Phytologist © 2018 New Phytologist Trust Molybdenum (Mo) is an essential micronutrient for most living organisms, including humans. Cereals such as rice (Oryza sativa) are the major dietary source of Mo. However, little is known about the genetic basis of the variation in Mo content in rice grain. We mapped a quantitative trait locus (QTL) qGMo8 that controls Mo accumulation in rice grain by using a recombinant inbred line population and a backcross introgression line population. We identified a molybdate transporter, OsMOT1;1, as the causal gene for this QTL. OsMOT1;1 exhibits transport activity for molybdate, but not sulfate, when heterogeneously expressed in yeast cells. OsMOT1;1 is mainly expressed in roots and is involved in the uptake and translocation of molybdate under molybdate-limited condition. Knockdown of OsMOT1;1 results in less Mo being translocated to shoots, lower Mo concentration in grains and higher sensitivity to Mo deficiency. We reveal that the natural variation of Mo concentration in rice grains is attributed to the variable expression of OsMOT1;1 due to sequence variation in its promoter. Identification of natural allelic variation in OsMOT1;1 may facilitate the development of rice varieties with Mo-enriched grain for dietary needs and improve Mo nutrition of rice on Mo-deficient soils
Influence of Ethnicity on the Accuracy of Non-Invasive Scores Predicting Non-Alcoholic Fatty Liver Disease
Objectives Presence of non-alcoholic fatty liver disease (NAFLD) can predict risks for diabetes, cardiovascular disease and advanced liver disease in the general population. We aimed to establish a non-invasive score for prediction of NAFLD in Han Chinese, the largest ethnic group in the world, and detect whether ethnicity influences the accuracy of such a score. Methods Liver fat content (LFAT) was measured by quantitative ultrasound in 3548 subjects in the Shanghai Changfeng Community and a Chinese score was created using multivariate logistic regression analyses. This new score was internally validated in Chinese and externally in Finns. Its diagnostic performance was compared to the NAFLD liver fat score, fatty liver index (FLI) and hepatic steatosis index (HSI) developed in Finns, Italians and Koreans. We also analyzed how obesity related to LFAT measured by H-1-MRS in 79 Finns and 118 Chinese with type 2 diabetes (T2D). Results The metabolic syndrome and T2D, fasting serum insulin, body mass index (BMI) and AST/ALT ratio were independent predictors of NAFLD in Chinese. The AUROC in the Chinese validation cohort was 0.76 (0.73-0.78) and in Finns 0.73 (0.68-0.78) (p Conclusion The predictors of NAFLD in Han Chinese are as in Europids but the Chinese have more LFAT for any given degree of obesity than Europids. Ethnicity needs to be considered when NAFLD is predicted using risk scores.Peer reviewe
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