Algerian kaolinite used for mullite formation

In the present study, mullite was synthesized through reaction sintering of Algerian kaolinite and high purity alumina. The raw powders were wet ball milled in a planetary ball mill. Powders' morphology and the microstructure of the sintered samples were characterized by means of a scanning electron microscope. An X-ray diffractometer equipped with a heating facility and a differential thermal analyzer were used to follow mullite formation. Cylindrical specimens were produced by uniaxial cold compaction at a pressure of 75 MPa and sintered at different sintering temperatures for different sintering times. The heating rate was 10 °C/min. It was found that Algerian kaolinite was suitable for mullite production through reaction sintering with pure Al₂O₃. Formation of complete mullite occurred at 1550 °C. A relative density of 94% (of the theoretical density) was achieved at a relatively low sintering temperature of 1600 °C and a sintering time of 4 h.     

Improved predictability, timing yield and power consumption using hierarchical highways-on-chip planning methodology

Interconnect mis-prediction is a major problem in nano-scale design that may diminish the quality of physical design algorithms or may even result in design divergence. In this paper, a new interconnect-planning methodology based on assume and enforce strategy is presented. In this methodology, some regions of the chip are planned to provide auxiliary routing resources and improve the interconnect delay of critical nets during the floor-placement process. Each of these wealthy regions is called a highway-on-chip. The location of highways and their resources are gradually determined during the hierarchical floor-placement process. Experimental results show that the performance, timing yield, predictability and power consumption of the attempted benchmarks are improved by 13.66%, 10.02%, 20.11%, and 6.83% on average. These improvements are obtained at the cost of about 7.82% runtime overhead and less than 0.8% wirelength growth.     

Long-term corrosion behaviour of low-carbon steel in anoxic environment: Characterisation of archaeological artefacts

In the context of nuclear waste storage, archaeological artefacts can be used as analogues for long-term prediction of iron corrosion behaviour. As many studies are based on laboratory simulations, it is necessary to establish a link between short and long-term behaviour. In this study, corrosion product crystalline structures on archaeological artefacts buried in soils and iron coupons immersed in synthetic environments have been compared. The occurrence of carbonated iron (siderite FeCO₃ and iron hydroxicarbonate Fe₂(OH)₂CO₃) has been observed on items from both environments using Raman micro-spectroscopy and X-ray micro-diffraction.     

Towards sensor array materials: can failure be delayed?

Further to prior development in enhancing structural health using smart materials, an innovative class of materials characterized by the ability to feel senses like humans, i.e. ‘nervous materials’, is discussed. Designed at all scales, these materials will enhance personnel and public safety, and secure greater reliability of products. Materials may fail suddenly, but any system wishes that failure is known in good time and delayed until safe conditions are reached. Nervous materials are expected to be the solution to this statement. This new class of materials is based on the novel concept of materials capable of feeling multiple structural and external stimuli, e.g. stress, force, pressure and temperature, while feeding information back to a controller for appropriate real-time action. The strain–stress state is developed in real time with the identified and characterized source of stimulus, with optimized time response to retrieve initial specified conditions, e.g. shape and strength. Sensors are volumetrically embedded and distributed, emulating the human nervous system. Immediate applications are in aircraft, cars, nuclear energy and robotics. Such materials will reduce maintenance costs, detect initial failures and delay them with self-healing. This article reviews the common aspects and challenges surrounding this new class of materials with types of sensors to be embedded seamlessly or inherently, including appropriate embedding manufacturing techniques with modeling and simulation methods.     

Randomized local elections

We propose and analyze two randomized local election algorithms in an asynchronous anonymous graph.     

Analysis of potential energy saving and CO2 emission reduction of home appliances and commercial equipments in China

China has implemented a series of minimum energy performance standards (MEPS) for over 30 appliances, voluntary energy efficiency label for 40 products, and a mandatory energy information label that covers 19 products to date. However, the impact of these programs and their savings potential has not been evaluated on a consistent basis. This paper uses modeling to estimate the energy saving and CO₂ emission reduction potential of the appliances standard and labeling program for products for which standards are currently in place, under development or those proposed for development in 2010 under three scenarios that differ in the pace and stringency of MEPS development. In addition to a baseline “frozen efficiency” scenario at 2009 MEPS level, the “Continued Improvement Scenario” (CIS) reflects the likely pace of post-2009 MEPS revisions, and the likely improvement at each revision step. The “Best Practice Scenario” (BPS) examined the potential of an achievement of international best-practice efficiency in broad commercial use today in 2014. This paper concludes that under “CIS”, cumulative electricity consumption could be reduced by 9503 TWh, and annual CO₂ emissions of energy used for all 37 products would be 16% lower than in the frozen efficiency scenario. Under a “BPS” scenario for a subset of products, cumulative electricity savings would be 5450 TWh and annual CO₂ emissions reduction of energy used for 11 appliances would be 35% lower.     

Automated gear fault detection of micron level wear in bevel gears using variational mode decomposition

Journal of Mechanical Science and Technology - Gearboxes have an important role in power transmission systems. For such systems, vibration-based fault diagnosis techniques are frequently used to...     

Auxiliary qubit selection: a physical synthesis technique for quantum circuits

Quantum circuit design flow consists of two main tasks: synthesis and physical design. Addressing the limitations imposed on optimization of the quantum circuit objectives because of no information sharing between synthesis and physical design processes, we introduced the concept of “physical synthesis” for quantum circuit flow and proposed a technique for it. Following that concept, in this paper we propose a new technique for physical synthesis using auxiliary qubit selection to improve the latency of quantum circuits. Moreover, it will be shown that the auxiliary qubit selection technique can be seamlessly integrated into the previously introduced physical synthesis flow. Our experimental results show that the proposed technique decreases the average latency objective of quantum circuits by about 11% for the attempted benchmarks.