Investigating the Impact of Familiarity and Product Conditions on The Ease of Use of a Product

Ease of use is one of the main criteria that customers consider when making a purchase decision. To provide a pleasant experience to the customers, offering products or services consisting of advanced features and functions is no longer enough, due to the existing competition in the global market. In reality, the ease of use of any product is influenced by the conditions of the product and the familiarity of the user. This study examines the influence of the familiarity and the product conditions on the ease of use of a product. This only explains how the conditions of the product and the fa-miliarity of the user, influence on the ease of use of a product when the usage hours of a product increases. A case study would be conducted to validate the results. The results of this study indicate that in the case where both the product conditions and the familiarity has been varied, the ease of use of the product has been increased from 0.229 to 0.380 gradually within the 10 weeks period. Through these results valuable guidance could be obtained by the manufacturers to identify how the ease of use level of a product deviates from the standard level when the usage hours of the product would increase.     

Crack initiation and propagation in ductile specimens with notches: experimental and numerical study

Failures of components and structures are often related to the presence of notches of different shapes. Damage modelling techniques have been proven capable of modelling the crack initiation and propagation in ductile materials (such as Al alloys). The Gurson–Tvergaard–Needleman (GTN) method and extended finite-element method (XFEM) are compared against original experiments to study the crack initiation and propagation processes in aluminium specimens with different notch shapes (V-shape, U-shape and square). Two regimes are considered in this study: quasi-static and impact uniaxial tensile loading. Results show that the load-bearing capability predicted with the two methods is somewhat lower compared to experiments; still, the crack shapes were predicted correctly, with the exception of the square-notch case, for which XFEM was unable to predict the correct shape due to limitations in the model formulation. This study provides information useful for the design of components with stress raisers that are exposed to different loading regimes and shows limitations in both the GTN- and XFEM-based approaches that in many cases underestimate the load-bearing capacity.     

基于通用生成函数的海上风电集电系统可靠性与经济性评估

集电系统的可靠性与经济性对整个海上风电场的经济效益和可靠运行有重要影响。在考虑海上风电场集电系统多状态特性的基础上,对交直流集电系统的多种拓扑进行研究,提出了基于通用生成函数的集电系统可靠性评估模型和指标,该方法可以实现多状态系统的有效化简,并建立交直流集电系统经济性评估模型。算例分析以一个装机容量400 MW的大型海上风电场为例,结合拓扑结构、交直流方案和风电机组容量对集电系统可靠性与经济性进行对比。结果表明,交流集电系统的可靠性仍然高于直流集电系统,但直流集电系统一些拓扑结构有成本优势。通过灵敏度分析说明了集电电压对集电系统电缆损耗成本和可靠性的影响。     

Application of Differential Scanning Calorimetry to Starch Gelatinization. III. Effect of Sucrose and Sodium Chloride

The influence of sucrose and salt on the gelatinization endotherm of wheat starch was examined using differential scanning calorimetry. Sucrose was found to decrease gelatinization energy (– ΔH_G) and to increase peak temperature (T_p) as its concentration was increased. Onset and conclusion temperatures (T₀ and T_c) were not affected by sucrose level. The effect of salt on the endotherm was more complex. A decrease in – ΔH_G occurred as the level of this solute in the aqueous phase was raised to 6% but further increases in salt caused it to rise again. Salt levels up to 9% caused increases in T₀ and T_p. With further rises in solute level, T₀ then decreased and T_p remained relatively constant. T_c rose slowly as salt concentration increased.     

Varieties of developmental reading disorder: genetic and environmental influences

There is widespread support for the notion that subgroups of dyslexics can be identified who differ in their reading profiles: Developmental phonological dyslexia is characterized by poor nonword reading, while developmental surface dyslexia is distinguished by a particular difficulty in reading irregular words. However, there is much less agreement about how these subtypes, and particularly the surface dyslexic pattern, are to be accounted for within theoretical models of the reading system. To assist in addressing this issue, the heritability of reading deficits in dyslexic subtypes was examined using a twin sample. Subjects' scores on (a) an exception word reading task and (b) a nonword reading task were used to create a subtype dimension, and surface and phonological dyslexic subgroups were selected from the ends of this distribution. Reading deficits were found to be significantly heritable in both subgroups. However, the genetic contribution to the group reading deficit was much greater in the phonological dyslexics than in the surface dyslexics. The finding of differential genetic etiology across subtypes suggests that there is at least partial independence in the development of the cognitive processes involved in reading exception words and nonwords. Also, the results support accounts of surface dyslexia which emphasize a strong environmental contribution.     

Water Binding Capacity of Commercial Produced Native and Modified Starches

The water binding capacities of five cereal and three tuberous starches, as well as fourteen modified wheat starches were determined using a Differential Scanning Calorimetry technique. Of the native starches, the tuberous ones had the highest moisture binding capacities. The influence of amylose/amylopectin ratio on water binding capacity was examined using waxy maize, normal maize and high amylose maize starches and increases in amylose level were found to result in reduced water binding. Chemical modification caused a reduction in the water binding capacity of wheat starch presumably as a result of blocking water binding sites on the starch molecules. Pregelatinized wheat starch showed a higher water binding capacity than wheat starch as a consequence of the disruption of the internal structure of the granule.     

A biopolymer‐based 3D printable hydrogel for toxic metal adsorption from water

Herein, we describe a 3D printable hydrogel that is capable of removing toxic metal pollutants from aqueous solution. To achieve this, shear‐thinning hydrogels were prepared by blending chitosan with diacrylated Pluronic F‐127 which allows for UV curing after printing. Several hydrogel compositions were tested for their ability to absorb common metal pollutants such as lead, copper, cadmium and mercury, as well as for their printability. These hydrogels displayed excellent metal adsorption with some examples capable of up to 95% metal removal within 30 min. We show that 3D printed hydrogel structures that would be difficult to fabricate by conventional manufacturing methods can adsorb metal ions significantly faster than solid objects, owing to their higher accessible surface areas. © 2019 Society of Chemical Industry     

Circulating fluidised bed co-combustion of coal and biomass

Circulating fluidised bed combustion (CFBC) is receiving wide research attention in view its potential as an economic and environmentally acceptable technology for burning low-grade coals, biomass and organic wastes, and thereby mixtures of them. Designs of the existing fluidised bed boilers for biomass combustion are mainly based on experience from coal combustion because the mechanism of combustion of biomass in fluidised beds is still not well understood. A good understanding of the combustion and pollutant formation processes and the modelling of the combustor can greatly avoid costly upsets of the plants.In this paper, the performance of CFBC burning coal and biomass mixtures was analysed. Experimental results were obtained from the combustion of two kinds of coal with a forest residue (Pine bark) in two CFB pilot plants (0.1 and 0.3 MW_th). The effect of the main operating conditions on carbon combustion efficiency was analysed. Moreover, a mathematical model to predict the behaviour of the co-combustion of coal and biomass wastes in CFB boilers has been developed and validated. The developed model can predict the different gas concentrations along the riser (O₂, CO, CH₄, etc.), and the carbon combustion efficiency. The experimental results of carbon combustion efficiencies were compared with those predicted by the model and a good correlation was found for all the conditions used.     

Enhancement of short chain fatty acid formation by pure cultures of probiotics on rice fibre

The formation of SCFA and the digestion of rice fibre using the following probiotics (Lactobacillus rhamnosus, Lactobacillus acidophilus, Bifidobacterium longum, Bifidobacterium breve) was compared using total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) from two varieties (milling grades) of rice. The milling grade of the rice had no significant effect (P < 0.05) on the SCFA formation and the digestion after 6, 24 and 48 h fermentation. SCFA formation from the fermentation of the fibre fractions of both rice varieties, followed the pattern of TDF > SDF > IDF for all the probiotics tested and major difference between the species was the time to form the SCFA. The pattern of SCFA formation from both rice fibre fractions was acetate > propionate > butyrate for all the organisms with no significant difference between the micro‐organisms (P < 0.05) although the ratio of acetate:propionate:butyrate was lower for Bifidobacterium spp. Lactobacillus spp. digested 60–80% of fibre whereas Bifidobaceria digested 75–85% of the rice fibre fractions from both rice samples. There was no significant difference in the ability of the micro‐organisms tested to utilise the different varieties of rice (P > 0.05).