Protection of Metals and Physical Chemistry of Surfaces - Shot peening is a treatment used to increase surface hardness and wear resistance. In this study, the effect of shot peening on the... 相似文献
International Journal of Wireless Information Networks - Dynamic variation of network topology in mobile ad hoc networks (MANET) forces network nodes to work together and rely on each other for... 相似文献
Electricity consumption is influenced by number of adults and children and their relationship at household level. Household income also plays a critical role on expenditure on electricity. Accordingly, this article presents a joint probability model of electricity demand based on occupants’ age grades and household income levels. A bottom-up strategy is developed using a micro level database of 70 Australian households. A neural regression-generalization technique is devised to estimate electricity demand using back-propagation and cognitive mapping. The aggregated result is then validated against 2012 Australian national census. Accordingly, the model is improved based on a top-down review. The results show per capita electricity demand by adult and child at 0.408 kW (69 kWh/week) and 0.226 kW (38 kWh/week), respectively. The equivalent dollar values are $13.6/week and $7.6/week in 2012. At macro level, the model reveals per capita demand by all individuals at 0.324 kW (54.35 kWh/week) equivalent to dollar value of $10.87/week, across Australia. The results also show higher percentage of per capita demand for adults in high and medium income classes, and the otherwise for low income class. Ratio of child’s demand over adult’s demand is highest among the low income households, and lowset among the middle income households, while best balance between adult and child per capita demand belongs to the high income.
Studies on stepped spillways as flood energy dissipators have been conducted to understand the hydraulics on the stepped face of roller-compacted concrete dams as well as overlays of embankment dams. Significant energy losses occur along the stepped chute so that the energy dissipation structure becomes smaller and more economic. In addition, considering the design discharge, downstream face slope, height of spillway, different combinations of spillway width and number of spillway steps may lead to different head losses. In each feasible combination, the remaining head after the steps should be dissipated by downstream energy dissipators. Design and construction of spillways and energy disspators are very cost-consuming and build up a major part of the dam's construction expenses. Thus, the cost of a financially viable stepped spillway project that consists of the steps’ cost and downstream dissipator's cost should be minimised. In this paper, the honey-bee mating optimisation (HBMO) algorithm is used to determine the best combination of design variables so as to minimise the total cost of both spillway chute and stilling basin. Results are compared with those previously obtained by genetic algorithm (GA) and show the promising potential of the HBMO algorithm in this field of application. 相似文献
In the present study, the influences of three different types of carbon (carbon black, graphite, and petroleum coke) on SiC synthesis via mechanical activation and sintering were evaluated. In this regard, the phase components, morphology, and the formation mechanism were investigated. SiC nanoparticles were detected to be formed after 4 h of milling and sintering at 1450°C, regardless of the sources of carbon. The carbon types exert their effects on the morphology of the as‐synthesized particles, where carbon black leads to form rod‐like SiC particles and the other two carbon types result in semi‐spherical SiC particles. This is due to the dominant mechanism in the mentioned process. The rod‐like particles obtained from the carbon black‐containing powder were synthesized via the VSL mechanism, whereas the solid‐state reactions occurred to form the SiC particles in the graphite‐ or petroleum coke‐containing samples. In the VSL mechanism, any increase in the milling time leads to facilitate the SiC formation due to entrance of Fe debris, whereas in the other samples (graphite or petroleum coke) the procedure is reversed. 相似文献
Structure–property relationship in typical polypropylene/polycarbonate/poly[styrene-b-(ethylene-co-butylene)-b-styrene] (PP/PC/SEBS) ternary blends containing maleated SEBS (SEBS-g-MAH) was investigated. Three grades of PC with different melt viscosities were used, and changes in blend morphology from PC/SEBS core–shell particles partially surrounded by SEBS-g-MAH to inverse SEBS/PC core–shell particles in PP matrix were observed upon varying the viscosity ratio of PC to SEBS. It was found that the viscosity ratio completely controls the size of the core–shell droplets and governs the type, population, and shape of the dispersed domains, as evidenced by rheological, mechanical, and thermomechanical behavioral assessments. Dynamic mechanical analysis of samples with common (PC–SEBS) and inverse (SEBS–PC) core–shell particles revealed that they show completely different behaviors: blends containing PC–SEBS presented a higher storage and loss modulus, while blends containing SEBS–PC exhibited a lower β-transition temperature. Moreover, ternary blends with PC cores showed the highest Young’s modulus values and the lowest impact strength, due to the different fracture modes of the blends containing PC–SEBS and SEPS–PC core–shell droplets, which present debonding and shell-fracture mechanisms, respectively. Morphological observations of blends with high-molecular-weight PC demonstrated the presence of detached droplets and rods of PC in the PP matrix, along with composite core–shell and rod-like particles. Micrographs of the fracture surfaces confirmed the proposed mechanisms, given the presence of stretched (debonded) PC (SEBS) cores encapsulated by SEBS (PC), which require more (less) energy to achieve fracture. The correlation between the mechanical and morphological properties proves that decreasing core diameter and shell thickness has positive effects on the impact strength but decreases the Young’s modulus. 相似文献