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

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

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

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

Development of an Energy-Efficient Rapid Microalgal Cell-Harvesting Method Using Synthesized Magnetic Nanocomposites

Due to high consumption and non-renewable nature of fossil fuels, rapid development of potential renewable energies such as biofuel derived from microalgae is necessary for achieving the goals of sustainable growth and carbon neutrality. However, the high energy consumption required for microalgal biomass harvesting is regarded as a major obstacle for large-scale microalgal biofuel production. In the present study, the marine green microalgae Tetraselmis sp. was used to investigate a rapid and energy-efficient biomass collection method among different methods such as gravity sedimentation, auto-flocculation (at target pH), flocculation by polymers followed by magnetic separation, and centrifugation. The results showed that sufficient high cell densities of microalgae were obtained under the optimized growth conditions after 21 days of cultivation, and the microalgae could be easily flocculated and collected by magnetic separation using synthesized magnetic nanocomposites. The results also showed that among the different methods, magnetic separation was more efficient for biomass harvesting because of its simple and fast processing steps as well as low energy consumption. However, further investigation on different target microalgal species and their cultivation conditions, such as salinity and medium pH, will be required before application for large-scale biofuel production in the future

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

Age composition and survival of public housing stock in Hong Kong

Emerging notably in more developed regions, building stock ageing which is characterised by shrinking new completions and falling “mortality” has been posing challenges to various stakeholders in built environment. To find way out of this transition, we need to know how long buildings will last these days and the factors leading to their “mortality”. By using data from 1950s till to date, a comprehensive investigation is conducted to analyse the age composition and life expectancy of public housing stock in Hong Kong. What comes after are survival analysis and empirical analysis of those demolished to identify the key factors leading to demolition. Presented in this paper are the preliminary findings as well as the research agenda on the theme to model age composition and survival of both private and public building stocks in Hong Kong and other similar cities in Asia Pacific Rim such as Adelaide and Singapore, together with research activities to formulate policies for sustainable urban management

Epithelioid hemangioma of the penis: case report and review of literature

<p>Abstract</p> <p>Introduction</p> <p>Epithelioid hemangioma is a rare vascular tumor found in the penis. It is essential to avoid misdiagnosis with Peyronie's disease and penile cancer, as management differs significantly.</p> <p>Case presentation</p> <p>We present a case of epithelioid hemangioma of the penis in a 50-year-old Caucasian man. We also review the literature to evaluate the incidence of benign vascular anomalies of the penis and their management.</p> <p>Conclusions</p> <p>Epithelioid hemangioma of the penis should be considered in the differential diagnosis of patients presenting with painful penile lumps. A thorough histological and immunohistochemical examination is required to make the diagnosis. Optimal management is complete local excision and periodic physical examination for local recurrence.</p