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Catalytic hydrogenolysis of lignin β-O-4 aryl ether compound and lignin to aromatics over Rh/Nb2O5 under low H2 pressure
No full textThe increasing risk of fossil fuels depletion due to surging energy demand has accelerated the search of alternative renewable sources. Lignin, one of the major components of lignocellulosic biomass, is the only abundant renewable natural resource for aromatic compounds. In this work, the effects of metals and process parameters were discussed via the catalytic hydrogenolysis of β-O-4 lignin model compound, 2-phenethyl phenyl ether. The best results were obtained over Rh/Nb2O5 with an overall conversion of 99.3% and exceptional selectivity of 98.9% to aromatic products when the hydrogenolysis was carried out at 260 °C and 0.1 MPa H2 for 4 h. The high efficiency is mainly attributed to the cooperation between Rh and NbOx at the perimeter sites, in which Rh particles are responsible for the dissociation of H2 and NbOx for activating C–O bonds. With respect to depolymerize of ash wood lignin, the liquid products were mostly aromatics over Rh/Nb2O5 under 0.1 MPa H2. The results achieved in this work provide a promising prospect towards valorization of lignin into production of valuable aromatic compounds under low hydrogen pressure
Species-specific holistic assessment of tree structure and defects in urban Hong Kong
No full text© 2020 Elsevier GmbH Sustainable urban forests require healthy trees with stable structures to improve provision of ecosystem services including air purification and climate mitigation to urban areas. Trees in compact residential areas are particularly prone to development of defects and unstable tree structures. We assessed in detail tree species, key structural and physiological defects, tree dimensions, growing habitats and planting site conditions of 38,156 trees in 102 sampled public housing estates (PHEs) in Hong Kong. The open spaces in PHEs allowed trees to grow in representative urban habitats. PHE attributes including estate age, number of trees, species richness and tree diversity were assessed. The associations among estates, species, tree structure and defects were investigated using Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA). The species-specific approach enlisted tree community, age, DBH and other biomass-structural traits in the data analysis and interpretation. The results showed diverse planting of 202 species from 56 families, with most species beset by multiple defects. The health and structure of two dominant tree species, Acacia confusa and Ficus microcarpa, were respectively influenced by inadequacies and stresses in planting environments, such as inclined surface of disturbed slopes, small pits and planters with poor soil quality, and soil not shielded by groundcover vegetation. Some tree defects of twigs, branches and trunks were associated with tree dimensions, especially tree height and its unnaturally high ratio to crown width and DBH. The findings verified the importance of a species-specific analysis to optimize urban-tree management and maximize benefits to the society
A Helping Hand 善心膳食
Get PDFAs we all learn to adjust and overcome the challenges of the COVID-19 pandemic, chefs, restauranteurs, hospitality companies and organisations around the world are finding ways to help and support the most vulnerable during these times.
在我們忙於克服新冠肺炎疫情所帶來的種種挑戰之際，全球各地的廚師、餐廳老闆、酒店品牌和各種機構已設法幫助在疫情中陷入困境的弱勢社群
Contemporary practices of strength and conditioning coaches in professional soccer
Get PDFThis study describes the contemporary practices of strength and conditioning coaches in professional soccer. Fifty-two strength and conditioning coaches from professional leagues across 18 countries completed an online survey, consisting of 45 questions, with eight sections: (a) background information, (b) muscular strength and power development, (c) speed development, (d) plyometrics, (e) flexibility development, (f) physical testing, (g) technology use, and (h) programing. A frequency analysis was used to assess and report responses to fixed response questions, and thematic-analysis used for open-ended questions to create clear, identifiable and distinct themes. All strength and conditioning coaches were educated to degree level or higher, 65% held strength and conditioning certifications and 54% held soccer coaching certifications. Concentric (100%) and eccentric (98%) modes of resistance were the most commonly prescribed, whereas the squat (including variations) (52%) was deemed the most important exercise for soccer players. Hang clean (33%) and multiple hops/lunges (89%) were the most programed Olympic weightlifting and plyometric exercises. Global Positioning Systems (94%) were the most utilized technology-based equipment. Time, scheduling and fixtures were the biggest issues faced, which made it difficult to periodize training programs and apply appropriate training loads. Furthermore, strength and conditioning coaches would like to further integrate technology to comprehensively monitor and test players, while also believing that technology will continue to be developed and integrated in the future. Strength and conditioning coaches from professional soccer can use the information from this study to review current practices and also provide ideas for diversifying or modifying future practices
Examining the potential effect of probiotic bacteria in reducing acrylamide
Get PDFAcrylamide is one of the process-induced contaminant formed during Maillard browning reaction. The presence of this toxicant in food products arose the public health concern due to its carcinogenicity. Different studies have evaluate the potential strategies to reduce acrylamide in foods. In this study, the new approach to reduce acrylamide by addition of probiotic bacteria was investigated
Plant Diversity and Plant Performance of Indoor and Outdoor Vertical Greening Systems in Hong Kong
No full textThis study aimed to examine the plant diversity and plant performance of vertical greening system (VGS) and how the hardware setup (including growing substrates) potentially affect plant performance. A total of 125 VGS (including 85 outdoor and 40 indoor VGS) were surveyed in Hong Kong. We recorded the type of VGS, species composition, frequency and plant coverage; substrate medium type, and plant performance. The findings revealed that indoor soilless VGS performed comparably well as on conventional soil, and outdoor soilless VGS performed significantly better than on soil. Regardless of substrate type, plants on indoor VGS performed better than outdoor VGS
Perceived benefits of studying general education for undergraduate students in the self-financing institutions in Hong Kong
No full text© 2020 National Institute of Education, Singapore. The Hong Kong Secondary Education system moved from the traditional “5 + 2 + 3 system to a new “3 + 3 + 4 structure in 2012 with emphasis on whole-person development. Under the new reform, students are required to undertake a block of new general education (GE) subjects apart from their disciplinary-specific education in their university curriculum. While prior studies mainly investigated the reform of GE and curriculum design, empirical studies on the perceived benefits of GE are sparse. The current study primarily aims to investigate the impact of GE on the generic skills of university students. A survey of 424 undergraduate students enrolled in a self-financing programme in four higher educational institutions in Hong Kong was conducted. The perceived benefits of GE were measured by seven variables, including communication, critical thinking and problem solving, team-work, leadership, lifelong learning and information management skills, ethics, and professional moral knowledge. This study can contribute to the understanding of the interrelationship between GE and the development of generic skills. Results will provide a guideline for educators and management when planning, developing, designing, and reviewing the general education curriculum
Anxious immobilities: an ethnography of copingwith contagion (Covid-19) in Macau
Get PDFIn February 2020, Macau became one of the first regions where the pandemic of coronavirus or Covid-19 affected the totality of social and economic life leading to increased anxieties over movement and distance. Although Macau has had very few actual cases of the virus – 46 in total – and no deaths from it, the Macau government rapidly instituted a lockdown. The aim of this article is to reflect on how the social experience of being in lockdown can provide insights into understanding the type of experience or condition that we provisionally term ‘anxious immobility.’ Such a condition is characterized by a total disruption of everyday rhythms and specifically anxious waiting for the normalization of activity while being the subject of biosocial narratives of quarantine and socially responsible. The paper is based upon 3 months of ethnographic research conducted by two researchers based in Macau. We also reflect upon some aspects of the politics of mobilities in the light of disruptions and friction points between Hong Kong, Macau, mainland China, and the rest of the world