A Feasibility Assessment of the Optimal Use of Hydrogen Drones in Fashion Item Replenishment Logistics

What should be considered in optimising the delivery routes for stock replenishment in a retail textile company? Traditional land-based truck delivery makes prompt returned or new products replenishments in small batches from one location to another impractical due to the high shipping costs incurred. Drones, which serve as digitized delivery equipment especially in western countries nowadays, realise last-mile and door-to-door deliveries. Breaking geographical barriers, drones raise operational efficiency and lower human- and equipment-related costs. Nonetheless, drone delivery regulations set legal boundaries. Added to this are the teething issues arisen in the drone deliveries across regulatory borders. As a consequence, retail replenishment performance and stock holding cost are rendered sub-optimal. In a fashion company’s setting, how do the small-batch deliveries using drones demonstrate their multifaceted advantages on the existing replenishment operation and the environment? A feasibility assessment able to show the logistics and environmental benefits of drone delivery with reference to the relevant regulations is yet to be in place to push boundaries

Co–MoCx supported on N-doped CNTs for efficient hydrogen evolution reaction under alkaline medium conditions†

The water splitting reaction has the potential to be a sustainable and environmentally friendly way of producing hydrogen as a fuel source, which is an important step in reducing our reliance on fossil fuels and mitigating climate change. Currently, most commonly used catalysts for water splitting are based on precious metals such as platinum and iridium, which are expensive and scarce. Therefore, finding new catalysts that are low-cost, abundant and efficient is of great importance for making water splitting economically viable on a large scale. It was found that pairing up Co nanoparticles (NPs) with MoCx boosted the hydrogen evolution reaction (HER) activity by more than 2-fold (Z10 = 130 mV, Tafel slope = 156.08 mV), compared with the pure Co NPs supported on N-doped carbon (Z10 = 337 mV) under alkaline medium conditions. Its activity is comparable to those of Pt single-atom catalysts (SACs) supported on a mesoporous carbon matrix. The good activity may be due to the modification of the D-band of Co by Mo doping and the relatively high electrochemically active surface area (ECSA) of 477.25 cm2, which is comparable to those of Ru SAC materials

Synergistic function of nanocluster and single atom catalysts for exceptional performance in the hydrogen production from solid hydrogen storage materials

The need of a sustainable low carbon transport and logistics has becoming one of the top agendas in Hong Kong after many countries set the emission targets in the Conference of Parties to the United Nation Framework Convention on Climate Change (COP21) and the policies on banning new petrol and diesel cars in 2030 or 2040. Promoting the development of renewable energy as an integral part of mitigating climate change has been stressed in the Policy Address of Hong Kong in 2021. With a target being set in Hong Kong to become carbon neutral by 2050, the exploration in the use of renewable energy as the major vehicles in transport and logistics is becoming critical to sustain its long-term decarbonisation strategy as a smart city with low carbon transport and logistics. Single-atom catalysts have been known to boost catalytic performance of many reactions using nanoparticles catalysts such as electrochemical reaction due to their higher surface energy and more efficient atomic utilization. However, their function in the hydrolysis of ammonia borane for hydrogen generation remains elusive. This project is to unravel their role in this type of reaction to lay the foundation for further improvement in catalytic performance. It was found that catalyst pyrolyzed at 800oC exhibited the best hydrogen releaseperformance. Catalysts first undergo an activation period due to the formation of an active single atom intermediate HO*-(Co-N2)- at optimal pH for fast H2O adsorption kinetics and eventually reach a maximum rB of 7833.4 ml H2 gCo-1 min-1 at 40°C

The relationship between organizational culture, job burnout and job satisfaction of the Hong Kong construction professionals

Thesis (B.Sc)--University of Hong Kong, 2010.Includes bibliographical references (p. 170-181).published_or_final_versio

Enhancing protection of vehicle drivers and road safety by deploying ADAS and Facial Features Pattern Analysis (FFPA) technologies

The latest technology associated with Intelligent Transportation Systems (ITS) have been designed with the aim to minimize the numbers of person injury in road accidents and improve the overall road safety. The driver behavior is one major concern in many accidents in HK urban road links. In particular, the driver\u27s attitudes, such as fatigue, drowsiness and concentration are the major causes to road accidents. It will affect the driver\u27s ability and decisions in properly controlling their vehicles. Very often, this kind of driver distraction is particularly obvious when driving after 2 to 3 hours from most research sources. In the traffic data sourced from Transport Department of HKSAR, around 82% of the personal injury in road accidents belongs to the driver\u27s fault. This paper used the latest technology and applied it to a group of transport vehicles, i.e. taxi. The objective is set up to monitor, record and analyze the fatigue and drowsiness situation of drivers by means of advanced AI system, facial recognition detection system (the sensors) and early warning devices (LDWS) via ADAS technology. The result will be used to give real time early warning and subsequent analysis for the transport operators or researchers for better and safer management of their transport fleets. The system aimed to have a good precaution and protection on all road users, including drivers, passengers and pedestrians. In turn, it largely saves our community resources, such as the medical and social services consumed on treating the injured persons

Highly Dispersed Rh/NbOx Invoking High Catalytic Performances for the Valorization of Lignin Monophenols and Lignin Oil into Aromatics

As fossil fuels are constantly depleted, valorization of lignocellulosic biomass into valuable aromatic compounds is of great significance but exceedingly challenging. In this work, the structure and catalytic performance of various Rh/Nb2O5 catalysts were studied in detail via the catalytic hydrodeoxygenation of a representative lignin monophenol compound 2-methoxy-4-propylphenol. The best catalytic performance was obtained over Rh/Nb2O5-400 (Nb2O5 calcined at 400 °C) with an exceptional 98% yield of propylbenzene under 0.5 MPa H2, which was mainly due to the cooperation between highly dispersed Rh metals and NbOx species, in which Rh was responsible for dissociation of H2 and NbOx for breaking of C−O bonds at the metal−support interface. Besides, the lignin oil obtained in depolymerization of raw pine wood was directly used as the substrate in the catalytic hydrodeoxygenation reaction over the Rh/Nb2O5-400 catalyst under 0.5 MPa H2. Encouragingly, the liquid products were identified and found that lignin oil was completely converted into C6−C10 hydrocarbons (\u3e99% selectivity) with an 80.1 mol % yield of aromatics. The results achieved in this work highlighted that high-value utilization of lignocellulosic biomass feedstocks to produce aromatic chemicals and liquid fuels could be achieved over Rh/Nb2O5 under a low hydrogen pressure

Recent advances on the catalytic conversion of waste cooking oil

The recovery of waste cooking oil has long been known for second life uses without chemical modification. However, the concepts of bioeconomy and circular economy are much more recent and include a ranges of tasks such as recovery, storage, use, chemical modification. International research into the use of modified and unmodified waste cooking oil and their potential uses has been the subject of incessant research in both academia and industry. The main purpose of this review is to present the recent breakthroughs obtained in the field of recovery of used cooking oils for the last decade. The review discusses advances obtained in major production pathways recently explored splitting in the following categories: (i) transesterification of waste cooking oil including biodiesel production with heterogeneous/homogeneous base and acid catalysis, magnetic heterogeneous catalysis, biocatalysis and alternative technologies such as electrolysis, continuous flow, microwave irradiation, ultrasound irradiation; (ii) transesterification of waste cooking oil including catalytic biolubricant production; (iii) interesterification; (iv) hydrolysis and (v) hydrodeoxygenation, hydrocracking and hydrogenation. This review also briefly overviews current understanding of waste cooking oil valorization and the underpinning mechanism

Improving the Energy Efficiency of Petrochemical Plant Operations: A Measurement and Verification Case Study Using a Balanced Wave Optimizer

The Chinese petrochemical industry is facing pressure to meet strict targets of energy consumption and carbon emission reductions. Water pumps are the primary equipment used in most chemical and agrochemical industries sectors since water is commonly used for cooling and heating purposes, but these pumps also consume a large amount of energy. Other uses of water pumps in these industries include producing steam for heating, preparing reaction media or absorptive reagents, rinsing products, and distilling. As for the electrical components of the water pump systems, current technologies of variable frequency drives and superconducting transmission lines are unable to increase the energy efficiency of these systems with a fixed load. However, the Balanced Wave Technology (BWT) is offered as a solution to overcome these limitations. In this report, a case study using a BWT optimizer is conducted on a closed loop water circulation system. Two BWTs are added to the individual motor-controlled section of each pump that is being used on the switchboard. For the first time, a detailed example was provided on how to implement option B of the International Performance Measurement and Verification Protocol (IPMVP) in China by evaluating the performance of BWT as an energy conservation measure. The evaluated periods included those of the baseline, post-installation, and actual performance of the optimizers. An average saving of energy of about 10.46% is recorded in a 5-week reporting period. On this basis, that annual electricity saved is estimated to be 66,447.18 kWh, which is equivalent to the emission of 68.94 metric tons of CO2e. This case study demonstrates in detail how option B of IPMVP can be implemented for BWTs applied on pumping systems. In addition to petrochemical production plants, other industries like textile and clothing sections, which are heavy users of water and electrical energy with fixed loads in the production processes of raw materials, fiber, yarn, and fabric, as well as textile-dyeing and final treatment, could benefit from applying this new technology

Synthesis of Sea Urchin-Like NiCo2O4 via Charge-Driven Self-Assembly Strategy for High Performance Lithium-Ion Batteries

In this study, hydrothermal synthesis of sea urchin-like NiCo2O4 was successfully demonstrated by a versatile charge-driven self-assembly strategy using positively charged poly(diallydimethylammonium chloride) (PDDA) molecules. Physical characterizations implied that sea urchin-like microspheres of ~ 2.5 μm in size were formed by self-assembly of numerous nanoneedles with a typical dimension of ~ 100 nm in diameter. Electrochemical performance study confirmed that sea urchin-like NiCo2O4 exhibited high reversible capacity of 663 mAh g−1 after 100 cycles at current density of 100 mA g−1. Rate capability indicated that average capacities of 1085, 1048, 926, 642, 261, and 86 mAh g−1 could be achieved at 100, 200, 500, 1000, 2000, and 3000 mA g−1, respectively. The excellent electrochemical performances were ascribed to the unique micro/nanostructure of sea urchin-like NiCo2O4, tailored by positively charged PDDA molecules. The proposed strategy has great potentials in the development of binary transition metal oxides with micro/nanostructures for electrochemical energy storage applications

A Randomized Controlled Trial of Auricular Transcutaneous Electrical Nerve Stimulation for Managing Posthysterectomy Pain

Background. A patient- and assessor-blinded randomized controlled trial was conducted to examine the effectiveness of auricular transcutaneous electrical nerve stimulation (TENS) in relieving posthysterectomy pain. Method. Forty-eight women who had undergone a total abdominal hysterectomy were randomly assigned into three groups (n = 16 each) to receive either (i) auricular TENS to therapeutic points (the true TENS group), (ii) auricular TENS to inappropriate points (the sham TENS group), or (iii) 20 minutes of bed rest with no stimulation (the control group). The intervention was delivered about 24 hours after the operation. A visual analogue scale was used to assess pain while resting (VAS-rest) and upon huffing (VAS-huff) and coughing (VAS-cough), and the peak expiratory flow rate (PEFR) was assessed before and at 0, 15, and 30 minutes after the intervention. Result. As compared to the baseline, only the true TENS group reported a significant reduction in VAS-rest (P = .001), VAS-huff (P = .004), and VAS-cough (P = .001), while no significant reduction in any of the VAS scores was seen in the sham TENS group (all P > .05). In contrast, a small rising trend was observed in the VAS-rest and VAS-huff scores of the control group, while the VAS-cough score remained largely unchanged during the period of the study. A between-group comparison revealed that all three VAS scores of the true TENS group were significantly lower than those of the control group at 15 and 30 minutes after the intervention (all P < .02). No significant between-group difference was observed in PEFR at any point in time. Conclusion. A single session of auricular TENS applied at specific therapeutic points significantly reduced resting (VAS-rest) and movement-evoked pain (VAS-huff, VAS-cough), and the effects lasted for at least 30 minutes after the stimulation. The analgesic effects of auricular TENS appeared to be point specific and could not be attributed to the placebo effect alone. However, auricular TENS did not produce any significant improvement in the performance of PEFR