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Through-tunnel estimates of vehicle fleet emission factors
No full textOn-road measurements of traffic-related gas and particle pollutant concentrations in three tunnels in Hong Kong and high resolution pollutant concentration profiles obtained while driving through the tunnels were used to derive the individual pollutant gradients using parametric and non-parametric (Sen–Thiel) slopes and compared with the commonly used entrance-exit two points calculation. The fuel based emission factors of measured pollutants for individual tunnels at different times of day were derived from gradients using a new method based on fuel carbon balance principle. Combined with the tunnel traffic volume and composition, the average tunnel emission factors were analyzed by linear regression to derive the diesel fleet emission factors. Average nitrogen oxides (NOx) and black carbon (BC) emission factor for diesel fleets are 29.3 ± 11.0 gNO2 kg−1 and 1.28 ± 0.76 g kg−1 of fuel, respectively. The results from the study were compared with the emission data from vehicle chasing approaches and the literature, showing reasonable agreement. Practical limitations and future direction for improvement of our method were also discussed. The method presented in this study provides a convenient drive-through approach for fast determination of tunnel and individual vehicle fleet emission factors. It can be used as an effective and fast approach to validate the emission inventory and to evaluate the effectiveness of policy intervention on the traffic emissions
A procurement performance model for construction frameworks
No full textCollaborative construction frameworks have been developed in the United Kingdom (UK) to create longer term relationships between clients and suppliers in order to improve project outcomes. Research undertaken into highways maintenance set within a major county council has confirmed that such collaborative procurement methods can improve time, cost and quality of construction projects. Building upon this and examining the same single case, this research aims to develop a performance model through identification of performance drivers in the whole project delivery process including pre and post contract phases. A priori performance model based on operational and sociological constructs was proposed and then checked by a pilot study. Factor analysis and central tendency statistics from the questionnaires as well as content analysis from the interview transcripts were conducted. It was confirmed that long term relationships, financial and non-financial incentives and stronger communication are the sociological behaviour factors driving performance. The interviews also established that key performance indicators (KPIs) can be used as an operational measure to improve performance. With the posteriori performance model, client project managers can effectively collaboratively manage contractor performance through procurement measures including use of longer term and KPIs for the contract so that the expected project outcomes can be achieved. The findings also make significant contribution to construction framework procurement theory by identifying the interrelated sociological and operational performance drivers. This study is set predominantly in the field of highways civil engineering. It is suggested that building based projects or other projects that share characteristics are grouped together and used for further research of the phenomena discovered
Candida albicans SAP9: a gene with novel function in hyphal development in Candida albicans
No full textObjectives: To investigate the role of C. albicans Sap9 in yeast-to-hyphal morphological transition.
Methods: In this study, SAP9 null mutant strain (Dsap9::hisG/Dsap9::hisG-URA3-hisG) was created by URA blaster method. Ura- phenotype strain was selected in synthetic complete glucose medium containing 0.1% 5-fluoroorotic acid, and complemented by URA3. Hyphal development of fungal cells (1×106 cfu/ml) was evaluated in both liquid and solid hyphal-inducing media, including Lee’s medium (pH 7.0), RPMI-1640, YPD+10% fetal bovine serum (FBS) and Spider’s medium at 37℃. To analyze the mRNA expression of hyphal-specific genes, fungal cells were prepared in the YPD containing 10% FBS at 37 ℃. Total RNA was extracted by SV Total RNA Isolation System and was reverse transcribed into cDNA using Superscirpt II. Gene expression was determined by Fast SYBR Green Master Mix, with the program: 95 ℃ incubation for 20s, and then 40 cycles of 95 ℃ for 1s and 60 ℃ for 20s. Student’s t test (P value \u3c 0.05) was used for statistical analysis.
Results: Compared with wild type SC5314 strain, SAP9 null mutant strain was defective in the hyphal development in both liquid and solid hyphal-inducting media. Gene expression analysis indicated that the expression level of transcription factor gene EFG1 was down-regulated by about 40% (P
Conclusions: C. albicans SAP9 might play a pivotal role in hyphal development in C. albicans via the cellular events mediated by EFG1
Hong Kong open space: discussion and revelation
No full textHong Kong, as one of the densely populated cities in the world, has a highly constrained land development system when it comes to planning open spaces in the city. Such a controlled urban planning framework has been a result of its unique social, economic, political and geographical factors. The intrinsic relationship between public and private land ownership constantly challenge the true definition of “public” and “private” spaces for its inhabitants. This paper aims to identify the different urban scenarios related to public and private open spaces and draws references from the Urban Design Roundtable Discussion held by the Hong Kong Institute of Urban Design (HKIUD) in September 2015 to best understand how urban design of open spaces can achieve a more sustainable urban design for the future
Using innovative customer relationship management technologies to explore the business opportunities of an ageing population and provide better service
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Energy optimization of a solar powered electric vehicle for a long distance race with crosswind effects
No full textElectric and hybrid vehicles arouse public interest because of the growing awareness of environmental issues. It is believed that solar car will be a viable option in the future. In this paper, we explore the effects of crosswind and its effects on electric power consumption for the IVE Hong Kong World Solar Challenge 2015 entry. Modelling of the effects of crosswind in various vehicle speeds shows that the power consumption can increase by up to 20% in strong winds. To date this area has not been fully covered. We also outline the design of the SOPHIE IV solar powered electric vehicle, which successfully completed the 3021km World Solar Challenge in 2013 in Australia. Lessons learned are incorporated into the new 2015 SOPHIE V. As a result of this research, the shape of the body shell is modified aerodynamically and a speed control support system is implemented to monitor the optimal speed in a bid to complete the race with the least energy and the time allotted. The solar car project brings students together from mechanical and electrical disciplines inspiring successful teamwork and leadership and promoting science and engineering as a bright promising career
Identification of disulfide isomerase ERp57 as a target for small molecule cardioprotective agent
No full textWe previously reported a novel danshensu analogue known as ADTM, which exhibited strong protective effects against oxidative stress-induced cellular injury and acute ischemic myocardial infarct in rat; however, the exact protein target of ADTM has not been fully characterized. In the present study, a biotin-conjugated ADTM analogue (BAA) was employed as molecular probe to identify its protein targets. BAA exhibited similar protective effect against oxidative stress-induced cell injury in H9c2 cardiomyoblast. A chemical proteomic approach identified ERp57 as the specific target for BAA. Further evaluation with Western blot and immunofluorescence staining assays confirmed the direct interactions between BAA and ERp57. Moreover, BAA displayed potent inhibitory effect on the catalytic activity of ERp57 in the insulin reduction assay. Molecular docking showed that BAA bound at the active site of ERp57. These data suggested that ERp57 is a potential target of cardioprotective danshensu analogues, and provided the basis for the further optimization of the cardioprotective compounds