Although widely used in our daily life, lithium (Li) -ion batteries fall short because the materials used are often scarce, toxic, and expensive. They also have safety issue in operation due to their organic based electrolytes. Beyond lithium-ion batteries, a low-cost magnesium (Mg) metal anode based aqueous Mg-ion battery has been developed first time by Professor Dennis Leung’s research team in the HKU Department of Mechanical Engineering. As Mg is the 5th most abundant metal element in the earth’s crust (three orders of magnitude more than Li), the advantages of low cost and non-toxicity make Mg a desirable alternative to Li as the anode material. The proposed battery shows a high discharge plateau of 2.4-2.0 V and an excellent rechargeability for over 700 stable cycles. This high operation voltage exceeds the counterpart of other multivalent-ion batteries, including zinc (Zn) metal and aluminum (Al) metal batteries. The mechanism behind was also revealed, where a conductive metallic oxide layer was facilitated by the chloride (Cl-) ions inside the water-in-salt electrolyte, providing ionic pathways for rechargeable battery operations. The team hopes that the chemical insights obtained in this work could inspire further optimization and bring attention to the overlooked development of rechargeable aqueous Mg metal batteries. This work uncovers the once dismissed possibility of aqueous Mg metal batteries and opens a new avenue in the field of post-lithium-ion batteries. Other project team members are Dr. Wending Pan (Research Assistant Professor) and Miss Sarah Leong (PhD student).
Month: October 2022
Many large earth structures (e.g. slopes, dams, and artificial islands) are made up of sand or sandy soil. The stability of these structures is a major concern of the public as well as the professional. The bitter memories of the deadly slope failures in Hong Kong in 1972 remind us of the importance of proper stability evaluation. The difficulty in predicting the mechanical behavior of sand and sandy soil mainly comes from the granular nature of these materials. A sand or sandy soil is an assembly of numerous small grains of varying size, shape and even mineral composition. It can exist over a spectrum of states that corresponds to a variety of responses, ranging from fluid-like flow to solid-like strain hardening. The groundwater brings additional difficulty and uncertainty. This talk will present some results and findings yielded from our long-term research endeavor at HKU, which is aimed to advance scientific understanding of the complex behaviors of granular earth materials and thereby provide better engineering solutions. Focus will be placed on the fascinating roles played by the small constituent particles. The significance of these findings to engineering practice will be open to discussion.
Spare parts management is a vital supporting function in aviation Maintenance, Repair,and Overhaul (MRO). Spare parts intralogistics (SPI), the operational perspective of spare parts management, significantly affects performance of MRO activities. This study proposes Cyber-Physical Spare Parts Intralogistics System (CPSPIS) to address the synchronization problems associated with the SPI business process and SPI resources. The proposed system applies Internet-of-Things technologies and unified representations to provide resources and operations traceability and visibility. Further, CPSPIS contributes several services with self-X abilities for real-time synchronization throughout the SPI process. In addition, CPSPIS develops applications and visualization tools for real-time cooperation between execution and decision-making. Finally, this study conducts a real-life case study in one of the largest aviation MRO organizations in Hong Kong, and discusses the quantitative and qualitative improvements of CPSPIS.
Identifying cause-effect relations is a fundamental primitive in a variety of areas of science and technology. The identification of causal relations is generally accomplished through statistical trials where alternative hypotheses about the causal relations are tested against each other. Traditionally, such trials have been based on classical statistics. But while classical statistics effectively describes the behavior of macroscopic variables, it becomes inadequate at the microscopic scale, described by quantum mechanics, where a richer spectrum of causal relations is accessible. In the past years, there has been an increasing interest in the study of causal relations among quantum variables. In this talk, Professor Giulio Chiribella will show that the counterintuitive features of quantum mechanics can be turned to our advantage, providing speed-ups in the identification of causal relations. These speed-ups have applications to the design of automated quantum machines and new quantum communication protocols.
Engineers traditionally construct networks of drains and pipes to efficiently divert rainwater away from urban areas. However, such conventional approaches do not focus on addressing environmental issues caused by urbanization, such as water quality degradation and reduced groundwater recharge. Nature-based solutions (NBS) are urban rainwater management approaches that support the natural cycle of water and utilize ecosystems’ functions. Commonly used NBS include bioretention cells, porous pavements, and river hyporheic restoration measures. NBS can simultaneously provide multiple benefits in addition to rainwater quantity and quality management, such as promoting biodiversity, increasing aesthetic values, and reducing urban heat island effects. In this TechTalk, Dr. Chui will introduce some NBS and discuss the opportunities and challenges of implementing them in Hong Kong.
This TechTalk panel discussion will first brief the participants on the basic information on the exciting National Manned Space Programme Recruitment of Payloads Specialists in HKSAR. This will be followed up by panel discussion on overseas experience of payload specialists and potential aerospace experiment ideas.
More information about the programme can be found in https://www.itib.gov.hk/en/psrecruitment/.
A rapidly aging population is one of the grand challenges facing the society. It is estimated that by 2050, the global population of people aged 65 or older will reach 1.6 billion. This is a major difficulty that many elders are experiencing severe limitations in mobility and manipulability in their daily lives, resulting in tremendous social and economic challenges. This talk will discuss a User-Centric Co-Creation (UC³) approach to develop intelligent robotic systems to assist mobility and manipulability as well as prevent falls. The UC³ methodology lays down a theoretical foundation for multi-disciplinary approach to the development of personalized wearable assistive systems. It will pave a new avenue to advance the ergonomics and gerontechnology beyond current horizons.
A warm welcome from Qi. Though we don’t have any quantum devices in Innovation Wing, if you are interested in quantum techniques and their potential applications and would like to know more about them , please don’t hesitate to come and talk to me!
Looking forward to seeing you around.