Search Results (94,546)

This study aims to examine the relationship between customs policy and the economic blocs of which Egypt is a member, with a focus on the theory of New Regionalism and modern trends in customs policies. Egypt joined numerous economic blocs following its accession to the world trade organization (WTO) in 1995, yet this membership has not yielded significant positive impacts on the performance of Egyptian exports or the trade balance. The study utilized panel data analysis of Egypt’s international trade from 2001 to 2023. The results indicate that, despite Egypt’s limited success in reaping the benefits of most economic blocs, largely due to the concentration of Egyptian exports in primary and agricultural products and the low tariff rates, factors such as customs clearance processes, tariff barriers, non-tariff barriers, regional trade agreements, and technology adoption still play a crucial role in influencing trade volume among member countries. The findings highlight the significance of effective customs procedures and the reduction of trade barriers in boosting trade volumes within regional trade agreements. The study proposes a strategy for Egypt’s customs policy to maximize benefits from economic blocs, focusing on four key areas: aligning customs policy planning with targeted export sectors to realize trade creation and trade diversion effects; fully implementing trade facilitation programs and liberalizing customs policy procedures; adopting a national strategy to stimulate high value-added export industries as a long-term solution; and adopting regional trade agreements that support cumulative origin as a short-term solution. Full article

The aim of this work is to analyze and model the performance of the distillation column of a catalytic cracking plant using fuzzy initial information. A system of mathematical models of the studied columns was developed, and we discussed the issues of modeling the distillation column of a catalytic cracking plant operating in conditions of fuzzy initial information. The system of mathematical models of the studied columns was developed on the basis of statistical and fuzzy information. The mathematical models of columns K-1, K-2 and K-3 were identified with regression and fuzzy regression equations, i.e., combined models of the main columns of the catalytic cracking plant were constructed. The purpose of this study was to create an optimal control system for the distillation column of a catalytic cracking unit using a mathematical model of the process. The results obtained in this work can be helpful during the design, modernization and optimization of equipment and installations, especially those used in the chemical and petrochemical industries. They can be useful both from a scientific and practical point of view, and they are also significant in terms of environmental protection, economy and mechanical engineering. Full article

Industrial computed tomography (CT) is widely used in the measurement field owing to its advantages such as non-contact and high precision. To obtain accurate size parameters, fitting parameters can be obtained rapidly by processing volume data in the form of point clouds. However, due to factors such as artifacts in the CT reconstruction process, many abnormal interference points exist in the point clouds obtained after segmentation. The classic least squares algorithm is easily affected by these points, resulting in significant deviation of the solution of linear equations from the normal value and poor robustness, while the random sample consensus (RANSAC) approach has insufficient fitting accuracy within a limited timeframe and the number of iterations. To address these shortcomings, we propose a spherical point cloud fitting algorithm based on projection filtering and K-Means clustering (PK-RANSAC), which strategically integrates and enhances these two methods to achieve excellent accuracy and robustness. The proposed method first uses RANSAC for rough parameter estimation, then corrects the deviation of the spherical center coordinates through two-dimensional projection, and finally obtains the spherical center point set by sampling and performing K-Means clustering. The largest cluster is weighted to obtain accurate fitting parameters. We conducted a comparative experiment using a three-dimensional ball-plate standard. The sphere center fitting deviation of PK-RANSAC was 1.91 µm, which is significantly better than RANSAC’s value of 25.41 µm. The experimental results demonstrate that PK-RANSAC has higher accuracy and stronger robustness for fitting geometric parameters. Full article

This study aims to provide a comprehensive exploration of the multifaceted barriers experienced by chefs working within the dynamic and demanding landscape of the hospitality industry. By delving into the intricacies of their work environment, we aim to shed light on the day-to-day hurdles they encounter, offering a detailed understanding of the obstacles they face. In our study, we employed a qualitative research framework to investigate the challenges faced by chefs in the hospitality sector, focusing on their unique experiences. Our data collection involved in-depth interviews with chefs in North Cyprus. Our findings reveal seven predominant problems within the culinary industry, encompassing workload and stress, customer expectations, menu creativity and innovation, team dynamics, career advancements, ingredient sourcing, and technology and automation. These insights serve as a valuable resource for industry professionals and researchers alike who are committed to enhancing the culinary profession and elevating the dining experience for customers. The originality of this study lies in its unique focus on addressing the underrepresented area of research concerning the specific barriers faced by chefs in the tourism and hospitality industry. By exploring the day-to-day hurdles encountered by chefs, this research contributes to both academic knowledge and practical insights that can enhance industry practices and ultimately improve the quality of dining experiences for guests. Full article

Dockless bike-sharing mobility brings considerable benefits to building low-carbon transportation. However, the operators often rush to seize the market and regulate the services without a good knowledge of this new mobility option, which results in unreasonable layout and management of shared bicycles. Therefore, it is meaningful to explore the relationship between the built environment and bike-sharing ridership. This study proposes a novel framework integrated with the extreme gradient boosting tree model to evaluate the impacts and threshold effects of the built environment on the origin–destination bike-sharing ridership. The results show that most built environment features have strong nonlinear effects on the bike-sharing ridership. The bus density, the industrial ratio, the local population density, and the subway density are the key explanatory variables impacting the bike-sharing ridership. The threshold effects of the built environment are explored based on partial dependence plots, which could improve the bike-sharing system and provide policy implications for green travel and sustainable transportation. Full article

The manuscript was prepared to conduct a thorough analysis and deepen the understanding of sustainable food production and diets within the context of the challenges posed by intensive agricultural practices and their environmental impacts, as well as their effects on human health. The rapid growth of the human population necessitates an increase in food production to meet nutritional needs. However, increasing the production of animal-derived products, which are significant protein sources, is likely to worsen undesirable consequences, such as global climate change, greenhouse gas emissions, and a larger carbon footprint. Traditional farming techniques also contribute to environmental contamination due to the use of synthetic fertilizers and pesticides. Transitioning to a sustainable food production model that addresses food needs while protecting consumer health and the environment is crucial. The challenge for the food industry and research centers is to find and develop the production of alternative sources of protein. In addition to the technological problems that must be solved, there is consumer education focused on healthy eating and overcoming psychological barriers related to the consumption of new foods. Full article

Underwater optical wireless communication (UOWC) is a field of research that has gained popularity with the development of unmanned underwater vehicle (UUV) technologies. Its utilization is crucial in offshore industries engaging in sustainable alternatives for food production and energy security. Although UOWC can meet the high data rate and low latency requirements of underwater video transmission for UUV operations, the links that enable such communication are affected by the inhomogeneous light attenuation and the presence of sunlight. Here, we present how the underwater spectral distribution of the light field can be modeled along the depths of eight stratified oceanic water types. We considered other established models, such as SPCTRL2, Haltrin’s single parameter model for inherent optical properties, and a model for the estimation of the depth distribution of chlorophyll-a, and present insights based on transmission wavelength for the maximum signal-to-noise ratio (SNR) under different optical link parameter combinations such as beam divergence and transmit power under “daytime” and “nighttime” conditions. The results seem to challenge the common notion that the blue-green spectrum is the most suitable for underwater optical communication. We highlight a unique relationship between the transmission wavelength for the optimal SNR and the link parameters and distance, which varies with depth depending on the type of oceanic water stratification. Our analyses further highlighted potential implications for solar discriminatory approaches and strategies for routing in cooperative optical wireless networks in the photic region. Full article

The catalytic hydrogenation of the toxic and harmful p-chloronitrobenzene to produce the value-added p-chloroaniline is an essential reaction for the sustainable chemical industry. Nevertheless, ensuring satisfactory control of its chemoselectivity is a great challenge. In this work, a N/S co-doped metal-free carbon catalyst has been fabricated by using cysteine as a source of C, N, and S. The presence of calcium citrate (porogen agent) in the mixture subjected to pyrolysis provided the carbon with porosity, which permitted us to overcome the issues associated with the loss of heteroatoms during an otherwise necessary activation thermal treatment. Full characterization was carried out and the catalytic performance of the metal-free carbon material was tested in the hydrogenation reaction of p-chloronitrobenzene to selectively produce p-chloroaniline. Full selectivity was obtained but conversion was highly dependent on the introduction of S due to the synergetic effect of S and N heteroatoms. The N/S co-doped carbon (CYSCIT) exhibits a mesoporous architecture which favors mass transfer and a higher doping level, with more exposed N and S doping atoms which act as catalytic sites for the hydrogenation of p-chloronitrobenzene, resulting in enhanced catalytic performance when compared to the N-doped carbon obtained from melamine and calcium citrate (MELCIT) used as a reference. Full article

Biomass gasification has emerged as a promising method for producing renewable energy, addressing both energy and environmental challenges. This review examines recent research on gasification simulations, covering a range of topics from process modeling to syngas cleanup. Key areas explored include techniques for syngas cleaning, addressing tar formation, and CO₂ capture methods. The aim of this review is to provide an overview of the current state of gasification simulation and identify potential areas for future research and development. This work serves as an invaluable resource for researchers, engineers, and industry professionals involved in biomass gasification modeling. By providing a comprehensive guide to biomass gasification simulation using Aspen Plus software and comparing various modeling approaches, it assists users in selecting the most effective tool for optimizing the design and operation of gasification systems. Full article

This paper presents a sustainable recycling process for the separation and recovery of tempered glass from end-of-life photovoltaic (PV) modules. As glass accounts for 75% of the weight of a panel, its recovery is an important step in the recycling process. Current methods, such as mechanical, chemical and thermal processes, often lead to contamination of the glass and pose significant environmental risks. In response to these challenges, a thermal–mechanical delamination approach is proposed in this study. The method utilizes controlled heat application (hot air gun) to weaken the adhesive bond between the glass and encapsulant, allowing for separation with a thin stainless steel wire. Various analytical methods, including X-ray diffraction analysis (XRD), X-ray fluorescence (XRF) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), were used to verify the effectiveness of the proposed method. The results show that the proposed method is effective. In less than a minute, the glass layer was separated and recovered with a success rate of over 99%, with no degradation of the material or release of gasses. The significance of this process lies in its ability to recover high-purity glass while minimizing the impact on the environment. This opens up the possibility of reusing the recovered tempered glass in new PV panels or other applications, reducing the need for virgin materials and lowering the overall environmental footprint of the solar energy industry. Full article

There is significant demand for high-purity DHA in the pharmaceutical industry. Traditionally, this high-purity DHA is extracted from raw materials with relatively low DHA content (10–20%), such as fish oil. Recently, through electroporation-induced mutation, a high-DHA-content strain of Schizochytrium sp. GCD2032 was isolated. To further enhance its DHA production, optimizations were conducted on the culture medium and fermentation conditions (in shaking flasks), as well as different nitrogen source concentrations (in a 5 L fermenter) for biomass, fatty acid content, and DHA content (as a percentage of total fatty acids). In a 5 L fermenter, Schizochytrium sp. GCD2032 achieved a biomass of 50 g/L, with fatty acid content of 55.71% and DHA content of 61.29%. Notably, the DHA content reached an impressive 341.45 mg/g of dry weight. This strain consistently produces high levels of fatty acids and DHA, demonstrating significant potential for pharmaceutical applications. Full article

Using Panax japonicus as research material, callus induction and culture were carried out, and high-yielding cell lines were screened to establish a suspension culture system that promotes callus growth and the accumulation of the “total saponins” (total content of triterpenoid glycosides or ginsenosides). Using the root as an explant, the medium for callus induction and proliferation was optimized by adjusting culture conditions (initial inoculation amount, carbon source, shaking speed, hormone concentration, culture time) and a high-yielding cell line with efficient proliferation and high total saponins content was screened out. The conditions of suspension culture were refined to find out the most suitable conditions for the suspension culture of callus, and finally, the suspension culture system was established. We found that the lowest (5%) contamination rate was achieved by disinfecting the fresh roots with 75% alcohol for 60 s, followed by soaking in 10% NaClO for 15 min. The highest induction rate (88.17%) of callus was obtained using the medium MS + 16.11 μmol·L⁻¹ NAA + 13.32 μmol·L⁻¹ 6-BA + 30.0 g·L⁻¹ sucrose + 7.5 g·L⁻¹ agar. The callus was loose when the callus subcultured on the proliferation medium (MS + 5.37 μmol·L⁻¹ NAA + 13.32 μmol·L⁻¹ 6-BA + 30.0 g·L⁻¹ sucrose + 3.8 g·L⁻¹ gellan gum) for 21 days. The callus growth was cultured in a liquid growth medium (MS + 5.37 μmol·L⁻¹ NAA + 13.32 μmol·L⁻¹ 6-BA + 30.0 g·L⁻¹ sucrose) with an initial inoculation amount of 40 g·L⁻¹, a shaking speed of 110 r/min and darkness. Cell growth was fastest with a culture period of 21 days. We replaced the growth medium with the production medium (MS + 5.37 μmol·L⁻¹ NAA + 13.32 μmol·L⁻¹ 6-BA + 30.0 g·L⁻¹ glucose) for maximum accumulation of total saponins. [Conclusion] A callus induction and suspension culture system for the root of P. japonicus was established. In this way, we can promote the accumulation of total saponins in callus cells and provide a basis for large-scale cell culture and industrial production of medicinal total saponins. Full article

A scientific understanding of the real estate sector’s role in the national economy is essential for facilitating reasonable and effective regulation and promoting economic development. By analyzing panel data from a sample of 67 countries between 2010 and 2018, we examine the role of the real estate sector in different countries and its determinants. This empirical study yields three main findings. Firstly, there is a strong correlation between the real estate sector and the financial services sector, the construction industry, as well as wholesale and retail trade. Notably, China’s real estate sector exhibits relatively high direct consumption of financial service activities compared to other major countries. Secondly, there is a transition trend in both the input and output of the real estate sector from primary and secondary industries towards service-oriented industries. Lastly, key determinants influencing the economic effects of the real estate sector in a country include economic growth, current national income level, expense structure of the economy, aging population, as well as urbanization speed. Full article

Dams significantly impact the environment, industries, residential areas, and agriculture. Efficient dam management can mitigate negative impacts and enhance benefits such as flood and drought reduction, energy efficiency, water access, and improved irrigation. This study tackles the critical issue of predicting dam occupancy levels precisely to contribute to sustainable water management by enabling efficient water allocation among sectors, proactive drought management, controlled flood risk mitigation, and preservation of downstream ecological integrity. Our research suggests that combining physical models of water inflow and outflow “such as evapotranspiration using the Penman–Monteith equation, along with parameters like water consumption, solar radiation, and rainfall” with data-driven models based on historical reservoir data is crucial for accurately predicting occupancy levels. We implemented various prediction models, including Random Forest, Extra Trees, Long Short-Term Memory, Orthogonal Matching Pursuit CV, and Lasso Lars CV. To strengthen our proposed model with robust evidence, we conducted statistical tests on the mean absolute percentage errors of the models. Consequently, we demonstrated the impact of physical model parameters on prediction performance and identified the best method for predicting dam occupancy levels by comparing it with findings from the scientific literature. Full article

Palm oil, derived from Elaeis guineensis, is a critical component of the global edible oil and industrial fat market. This review provides a comprehensive overview of the sustainability of the palm oil chain, focusing on industrial applications, environmental implications, and economic sustainability. The processing of palm oil, from fruit pulp to refined oil, is detailed, highlighting the importance of refining in maintaining quality and extending application ranges. While palm oil offers health benefits because of its rich fatty acid composition and antioxidant properties, its production poses significant environmental challenges. This review underscores ongoing efforts to balance technological and culinary demands with environmental stewardship and sustainable economic growth. Emerging trends, including interspecific hybrids such as E. guineensis and E. oleifera, are discussed for their potential to increase sustainability and productivity. Full article