- document
-
Zhang, Q. (author), Ye, G. (author)When a concrete structure is exposed to high temperature, the mechanical damage and chemical transformation take place simultaneously, which will change the microstructure of material. On the other hand, the mechanical properties and transport properties depend on the development of microstructure of cement paste. In order to study the...journal article 2011
- document
-
Wei, J. (author), Ye, H. (author), Van Zeijl, H.W. (author), Sarro, P.M. (author), Zhang, G.Q. (author)A micro-electro-mechanical-system (MEMS) based, temperature triggered, switch is developed as a cost-effective solution for smart cooling control of solid-state-lighting systems. The switch (1.0x0.4 mm2) is embedded in a silicon substrate and fabricated with a single-mask 3D micro-machining process. The device switches on at a designed...journal article 2012
- document
-
Zhang, Q. (author), Ye, G. (author)Portland cement paste is a multiphase compound mainly consisting of calcium-silicate-hydrate (CSH) gel, calcium hydroxide (CH) crystal, and unhydrated cement core. When cement paste is exposed to high temperature, the dehydration of cement paste leads to not only the decline in strength, but also the increased pore pressure in the paste. In this...journal article 2012
- document
-
Zhang, Y. (author), Ye, G. (author)The pressure to reach sustainability favours the development of ternary composite cement. The synergistic effect on mechanical behaviour at 28 days between limestone powder (LP) and pozzolanic additives, i.e. fly ash (FA) and blast furnace slag (BFS), has been documented. In order to better understand the synergistic effect, this article...conference paper 2012
- document
-
Zhang, Y. (author), Wu, B. (author), Zhou, J. (author), Ye, G. (author), Shui, Z. (author)Concrete containing supplementary cementitious materials (SCMs) has different durability properties from that containing pure Portland cement. The durability of concrete is always associated with the properties of microstructure, especially pore structure. Pressurization–Depressurization Cycling Mercury Intrusion Porosimetry (PDC-MIP) was...conference paper 2014
- document
-
Zhang, Y. (author), Ye, G. (author)Concrete is seldom saturated due to its self-desiccation. Even the submerged concrete structures may remain unsaturated for quite a long time. It has been reported the saturation level of pore solution has significant effect on species penetration. However, very little work was proposed regarding the transport properties and serviceability of...conference paper 2014
- document
-
Zhang, Y. (author), Ye, G. (author)Due to environmental (low CO2 emission) and economic benefit, supplementary cementitious materials (SCMs) have been widely used in reinforced concrete structures. However, the question from engineering practice is to which extend these blended mixtures do meet the future durability criteria. Chloride ingression is nowadays considered as the main...conference paper 2015
- document
-
Chen, Xianping (author), Ye, H. (author), Fan, Xuejun (author), Ren, Tianling (author), Zhang, Kouchi (author)Heat pipes (HPs) have received considerable attention in recent decades, especially in the field of cooling electronics, which requires the removal of added heat from an area of limited volume to the environment. Small HPs are widely used in electronic applications, which are normally limited by the compact structure and dimensions of the...journal article 2016
- document
-
Zhang, Y. (author), Ye, G. (author)The purpose of this paper is to investigate the pore connectivity and its influence on chloride transport property in cementitious materials under saturated condition. Mercury intrusion porosimetry experiment was carried out on a variety of hydrated cement pastes curing up to one year. By repeating pressurization-depressurization cycles, pore...conference paper 2016
- document
-
Zhang, Y. (author), Ye, G. (author)In engineering practise, interior relative humidity (RH) of concrete significantly affects the transport properties and thus the service life of concrete structures. In this paper, the development of RH due to self-desiccation in blended cement pastes was studied from 1 day to 1.5 years. The pore structure and non-evaporable water content at...conference paper 2016
- document
-
Ye, H. (author), Leung, Stanley Y.Y. (author), Wong, K.Y. (author), Chen, Xianping (author), Lin, Kai (author), Fan, J. (author), Kjelstrup, Signe (author), Fan, Xuejun (author), Zhang, Kouchi (author)Using the analogue of the electric inductance, we reveal the properties of the thermal inductance in GaN-based light-emitting diode devices by testing their transient thermal behaviors. We find that the devices exhibit a transient thermal response under step-down or step-up currents and observe notable inductive phenomena of the temperature...journal article 2016
- document
-
Zhang, Y. (author), Ye, G. (author)In this paper, a new analytic model for predicting chloride diffusivity in unsaturated cementitious materials is developed based on conductivity theory and Nernst-Einstein equation. The model specifies that chloride diffusivity in unsaturated cementitious materials can be mathematically described as a function of chloride diffusivity in...conference paper 2017
- document
-
Zhang, Y. (author), Ye, G. (author)Experiments are carried out to investigate the chloride diffusivity in partially saturated ordinary Portland cement mortars with water-to-cement (w/c) ratios of 0.4, 0.5 and 0.6. Based on resistivity measurement and Nernst-Einstein equation, the chloride diffusivities of cement mortars at various water saturations are estimated. The pore...conference paper 2017
- document
-
Sun, B. (author), Fan, Xuejun (author), Li, Lei (author), Ye, H. (author), van Driel, W.D. (author), Zhang, Kouchi (author)This paper studies the interaction of catastrophic failure of the driver and LED luminous flux decay for an integrated LED lamp with an electrolytic capacitor-free LED driver. Electronic thermal simulations are utilized to obtain the lamp's dynamic history of temperature and current for two distinct operation modes: constant current mode (CCM...journal article 2017
- document
-
Hu, Fa-Fei (author), Tang, H. (author), Ye, H. (author), Chen, X. (author), Zhang, Kouchi (author)The sensing behavior of monolayer tin sulfide (SnS) for four gas molecules (NH<sub>3</sub>, NO<sub>2</sub>, CO, and H<sub>2</sub>O) are studied by the first-principle calculation based on density-functional theory. We calculate adsorption energy, adsorption distance, and Hirshfeld charge to estimate the adsorption ability of monolayer SnS for...journal article 2017
- document
-
Tang, H. (author), Ye, H. (author), Wong, K.Y. (author), Leung, Stanley Y.Y. (author), Fan, Jiajie (author), Chen, Xianping (author), Fan, Xuejun (author), Zhang, Kouchi (author)The objective of this study is to quantitatively evaluate the impacts of LED components on the overdriving reliability of high power white LED chip scale packages (CSPs). The reliability tests under room temperature are conducted over 1000 h in this study on CSP LEDs with overdriving currents. A novel method is proposed to investigate the...journal article 2017
- document
-
Sun, B. (author), Fan, Xuejun (author), Ye, H. (author), Fan, Jiajie (author), Qian, Cheng (author), van Driel, W.D. (author), Zhang, Kouchi (author)In this paper, an integrated LED lamp with an electrolytic capacitor-free driver is considered to study the coupling effects of both LED and driver's degradations on lamp's lifetime. An electrolytic capacitor-less buck-boost driver is used. The physics of failure (PoF) based electronic thermal simulation is carried out to simulate the lamp's...journal article 2017
- document
-
Tang, H. (author), Ye, Huai-Yu (author), Chen, Xian-Ping (author), Qian, Cheng (author), Fan, Xue-Jun (author), Zhang, Kouchi (author)In this paper, the heat transfer performance of the multi-chip (MC) LED module is investigated numerically by using a general analytical solution. The configuration of the module is optimized with genetic algorithm (GA) combined with a response surface methodology. The space between chips, the thickness of the metal core printed circuit board...journal article 2017
- document
-
Zhang, Shizhe (author), Keulen, Arno (author), Arbi Ghanmi, K. (author), Ye, G. (author)The feasibility of a waste glass powder residue (GP) from glass recycling as partial mineral precursor to produce alkali-activated materials is investigated. GP served as powder coal fly ash (PCFA) replacement within a reference system composed of 50% PCFA and 50% ground granulated blast furnace slag (GGBS). Compared with PCFA, GP was better...journal article 2017
- document
-
Qian, C. (author), Mirza Gheytaghi, Amir (author), Fan, J. (author), Tang, H. (author), Sun, B. (author), Ye, H. (author), Zhang, Kouchi (author)As an increasing attention towards sustainable development of energy and environment, the power electronics (PEs) are gaining more and more attraction on various energy systems. The insulated gate bipolar transistor (IGBT), as one of the PEs with numerous advantages and potentials for development of higher voltage and current ratings, has been...journal article 2018