The challenge of rural electrification has become more challenging today than ever before. Grid-connected and off-grid microgrid systems are playing a very important role in this problem. Examining each component’s ideal size, facility system reactions, and other microgrid analyses, this paper proposes the design and implementation of an off-grid hybrid microgrid in Chittagong and Faridpur with various load dispatch strategies. The hybrid microgrids with a load of 23.31 kW and the following five dispatch algorithms have been optimized: (i) load following, (ii) HOMER predictive, (iii) combined dispatch, (iv) generator order, and (v) cycle charging dispatch approach. The proposed microgrids have been optimized to reduce the net present cost, CO2 emissions, and levelized cost of energy. All five dispatch strategies for the two microgrids have been analyzed in HOMER Pro. Power system reactions and feasibility analyses of microgrids have been performed using ETAP simulation software. For both the considered locations, the results propound that load-following is the outperforming approach, which has the lowest energy cost of $0.1728/kWh, operational cost of $2944.13, present cost of $127,528.10, and CO2 emission of 2746 kg/year for the Chittagong microgrid and the lowest energy cost of $0.2030/kWh, operating cost of $3530.34, present cost of 149,287.30, and CO2 emission of 3256 kg/year for the Faridpur microgrid with a steady reaction of the power system.
Against the backdrop of anti-globalization rhetoric, this paper summarizes our joint book entitled Going Beyond Aid (Lin and Wang, 2017a) and discusses the prospects for development finance in the broad context of Belt and Road Initiative (BRI). Based on the New Structural Economics (Lin, 2010; 2011), here we focus on China’s demonstrated comparative advantages in infrastructure, e.g. in hydropower and high-speed railways (HSR). In addition, long-term orientation (LTO) and patient capital are latent comparative advantages that many Asian economies possess, and are critical for the Belt and Road Initiative. Only if these comparative advantages are utilized can these economies cooperate to potentially achieve win-win.
Nanotechnology is a subject that studies, processes, and applies various functional materials, equipment, and systems, and controls substances on a nanoscale. Nanomedicine refers to its application in diagnosing, treating, preventing, and monitoring various diseases. Drugs administered through eye drops must travel a long distance to avoid various eye barriers reaching the posterior segment of the eye, to achieve the lowest drug level. This review focuses on nanotechnology-based eye disease treatment systems and highlights the obstacles affecting the drug management of eyes and nano-systems for the treatment of eye diseases. This paper summarizes the development prospect of nanotechnology and the challenges it faces in the treatment and diagnosis of ophthalmic diseases, to provide information and new ideas for the implementation of treatment and the development of a refractory eye disease management system.
The intermittent flow cold storage heat exchanger is one of the most important components of the pulse tube expansion refrigerator based on the reverse Brayton cycle. In the experimental system, the volume and heat transfer of the helical tube play a decisive role in the stable operation of the whole experimental system. However, there are few studies on heat transfer in a helical tube under helium working medium and intermittent flow conditions. In this paper, a process and method for calculating the volume of a helical tube are proposed based on the gas vessel dynamics model. Subsequently, a three-dimensional simulation model of the helical tube was established to analyze the heat transfer process of cryogenic helium within the tube. The simulations revealed that the temperature of helium in the tube decreases to the wall temperature and does not change when the helical angle exceeds 720°. Moreover, within the mass flow rate range of 1.6 g/s to 3.2 g/s, an increase in the mass flow rate was found to enhance the heat transfer performance of the helical tube. This study provides a reference for the selection and application of a helical tube under intermittent flow conditions and also contributes to the experimental research of inter-wall heat exchanger and pulse tube expansion refrigerators.
The objective of the study was to analyze green marketing in the promotion of environmentally responsible and sustainable practices in the development of resilient infrastructure in Peru. The methodology used was qualitative and interpretative, the documentary design based on the systematic review of scientific literature. The PRISMA model was applied for the selection of units of analysis, resulting in 36 articles out of an initial total of 950. Content analysis was used to examine the documents, following a detailed procedure that included the use of Grounded Theory to categorize and analyze the data. The results highlighted the importance of integrating green marketing and sustainable practices into resilient infrastructure planning and development. Key strategies were identified that include promoting environmental responsibility, adopting sustainable technologies in construction, and implementing policies that foster urban resilience and sustainability. The findings highlight the adoption of a comprehensive approach that combines green marketing with resilient infrastructure planning and development to address environmental challenges and promote sustainable development in Peru.
Copyright © by EnPress Publisher. All rights reserved.