Over the past 20 years, civil aviation has substantially reduced its environmental impact to augment sustainable transportation. In Spain, the domestic market has been habitually characterized by a few enterprises providing air transport services linked to scheduled flights on domestic corridors. Because of geographic diversity and the highly concentrated population characterizing this southern European country, many of them could not be supplied by alternative transport modes in terms of both time and distance by comparison with air transportation. For air quality monitoring from 139 national corridors, this paper aims to study related aviation emissions to conduct an economic analysis in terms of positive or negative externalities. For such purposes, the study focused on these domestic routes served by the five most important Spanish airports, specifically on the number of passengers transported from 2011 to 2020. Up to 10 aircraft types representing no more than 89% of regular opera... [more]

Biocatalysis entails the use of enzymes, which are catalytically active proteins, to speed up reactions so that products can be obtained swiftly and accurately [...]

To improve the understanding of the mixing performance of double shaft, batch-type paddle mixers, the discrete element method (DEM) in combination with a Plackett−Burman design of experiments simulation plan is used to identify factor significance on the system’s mixing performance. Effects of several factors, including three material properties (particle size, particle density and composition), three operational conditions (initial filling pattern, fill level and impeller rotational speed) and three geometric parameters (paddle size, paddle angle and paddle number), were quantitatively investigated using the relative standard deviation (RSD). Four key performance indicators (KPIs), namely the mixing quality, mixing time, average mixing power and energy required to reach a steady state, were defined to evaluate the performance of the double paddle mixer. The results show that the material property effects are not as significant as those of the operational conditions and geometric param... [more]

Phenol is a highly persistent environmental pollutant and is toxic to living organisms. The main objective of this study is to observe the phenol degradation performance by free and immobilized Pseudomonas putida (P. putida) in batch and continuous reactors, respectively. Batch experiments were evaluated to determine the maximum specific growth rate, saturation constant, inhibition constant, and cell yield. These kinetic parameters were used as the input values for the continuous-flow immobilized cells model. The immobilized cells model was validated by experimental results obtained from an immobilized cells continuous reactor. The model-predicted and experimental results showed good agreement for phenol effluent concentration in the continuous mode. In the steady-state condition, high phenol removal was achieved under various hydraulic retention times. The corresponding removal of phenol ranged from 93.3 to 95.9%, while the hydraulic retention times were maintained at 3.1−10.5 h. Furt... [more]

Solar energy is the most available renewable resource and has great potential for various applications. Solar heat pumps are limited when operating alone due to weather and the unstable and intermittent nature of solar energy. The idea of combining a solar collector with an air-source heat pump (ASHP) is proposed to solve the problems. Taking solar energy and air energy as the heat source of the system can improve the heat collection efficiency and heating performance coefficient of the dual-supply heating system in realizing the efficient and stable operation of the whole unit. This study investigated the application of a solar−air-source heat pump (S/AS-HP) dual-supply heating system for a residential building in Lhasa and compared the winter work performance and economic benefits of three different heating forms: solar−air-source heat pump, air-source heat pump, and solar−electric auxiliary heating systems. A simulation model was established and analyzed using the measurement data.... [more]

Jasmonates (JAs) are phospholipid-derived hormones that regulate plant development and responses to environmental stress. The synthesis of JAs and the transduction of their signaling pathways are precisely regulated at multiple levels within and outside the nucleus as a result of a combination of genetic and epigenetic regulation. In this review, we focus on recent advances in the regulation of JA biosynthesis and their signaling pathways. The biosynthesis of JAs was found to be regulated with an autocatalytic amplification mechanism via the MYC2 regulation pathway and inhibited by an autonomous braking mechanism via the MYC2-targeting bHLH1 protein to terminate JA signals in a highly ordered manner. The biological functions of JAs mainly include the promotion of fruit ripening at the initial stage via ethylene-dependent and independent ways, the regulation of mature coloring via regulating the degradation of chlorophyll and the metabolism of anthocyanin, and the improvement of aroma c... [more]

In 2016, obese patients represented 13% of the worldwide adult population, and by 2030, they are projected to make up 34%. Obesity is an incommunicable disease, but it can induce many health problems. The groups consisted of a control, a 65% high-fat group, and a 250 mg/kg P. erosus group. Several biomarkers, such as body weight gain, the presence of TC/LDL/HDL in the serum, the weight of fat tissue, and liver weight/morphology, were investigated to define the anti-obesity mechanisms of P. erosus, and the adipogenesis pathway was studied. P. erosus suppressed body weight gain, decreased TC and LDL, prevented fat tissue weight gain, and prevented liver weight gain by blocking lipid droplet accumulation. P. erosus effectively decreased the up-regulated levels of leptin, significantly controlled both C/EBPα and PPARγ levels, and prevented increased FAS expression levels. We concluded that P. erosus effectively controlled obesity by regulating leptin-C/EBPα-PPARγ and FAS and might be a pro... [more]

One of the most difficult challenges in medicine is predicting heart disease at an early stage. In this study, six machine learning (ML) algorithms, viz., logistic regression, K-nearest neighbor, support vector machine, decision tree, random forest classifier, and extreme gradient boosting, were used to analyze two heart disease datasets. One dataset was UCI Kaggle Cleveland and the other was the comprehensive UCI Kaggle Cleveland, Hungary, Switzerland, and Long Beach V. The performance results of the machine learning techniques were obtained. The support vector machine with tuned hyperparameters achieved the highest testing accuracy of 87.91% for dataset-I and the extreme gradient boosting classifier with tuned hyperparameters achieved the highest testing accuracy of 99.03% for the comprehensive dataset-II. The novelty of this work was the use of grid search cross-validation to enhance the performance in the form of training and testing. The ideal parameters for predicting heart disea... [more]

The design parameters of a mixing system have a major impact on the quality of the final product. Therefore, identifying the optimum parameters of mixing systems is highly relevant to various industrial processes dealing with particulate flows. However, the studies on the influences of the mixer’s design features are still insufficient. In this study, the Discrete Element Method (DEM) is used to examine the impact of paddle angle, width, and gap on the mixing performance of a twin paddle blender. The mixing performance and particle flow are assessed using the relative standard deviation (RSD) mixing index, velocity field, diffusivity coefficient, granular temperature, the force acting on particles, and the mixer’s power consumption. The mixing performance is highest for a paddle angle of 0° at the cost of the highest forces acting on particles. The paddle width is indicated as a critical factor for achieving better mixing quality. In contrast, the powder mixing efficiency and the mixer... [more]

The evolution of mesoscale structures of particle packing in binary composite packed beds and their effects on flow characteristics and wall effects were investigated using the discrete element method (DEM) and computational fluid dynamics (CFD). The DEM model was used to build a series of randomly mixed packing structures of particles in accordance with the dynamic change of mass ratio between particles in two size ranges, which were then confirmed by the findings of an X-ray tomography (CT) scan. The results show that the packing structure of b25s75 was conducive to reducing the influence of wall effect in packed bed reactors. For b25s75, the dimensionless distance of radial porosity fluctuation from the wall is 0.3705, which is the smallest among the five packing models, indicating that this structure plays a suppressive role on the wall effect. In addition, the uniformity of velocity and temperature distributions in both the radial and axial directions of different packing structur... [more]

Composting is the most adaptable and fruitful method for managing biodegradable solid wastes; it is a crucial agricultural practice that contributes to recycling farm and agricultural wastes. Composting is profitable for various plant, animal, and synthetic wastes, from residential bins to large corporations. Composting and agricultural waste management (AWM) practices flourish in developing countries, especially Pakistan. Composting has advantages over other AWM practices, such as landfilling agricultural waste, which increases the potential for pollution of groundwater by leachate, while composting reduces water contamination. Furthermore, waste is burned, open-dumped on land surfaces, and disposed of into bodies of water, leading to environmental and global warming concerns. Among AWM practices, composting is an environment-friendly and cost-effective practice for agricultural waste disposal. This review investigates improved AWM via various conventional and emerging composting proc... [more]

Whether cities can attain a win-win situation with simultaneous environmental protection and economic growth is a compelling issue in current urban development. It will be of great practical significance to comprehensively evaluate the implementation effect of the multi-dimensional goals of an urban development from the perspective of a green total factor productivity (GTFP) evaluation. The paper places pollution reduction and carbon reduction into the research framework of GTFP, introduces the SBM-DDF model to evaluate the urban GTFP of 58 cities in the Yellow River Basin (YRB) from 2006 to 2020, and employs the panel regression model to empirically study the factors influencing the urban GTFP of the region. The results are obtained as follows: (1) from the perspective of time range, the urban GTFP in the basin displays an evolutionary trend of first declining and then mounting, demonstrating the highest GTFP in the downstream, the second-highest in the midstream and the lowest in the... [more]

The technology for storing thermal energy as sensible heat, latent heat, or thermochemical energy has greatly evolved in recent years, and it is expected to grow up to about 10.1 billion US dollars by 2027. A thermal energy storage (TES) system can significantly improve industrial energy efficiency and eliminate the need for additional energy supply in commercial and residential applications. This study is a first-of-its-kind specific review of the current projected performance and costs of thermal energy storage. This paper presents an overview of the main typologies of sensible heat (SH-TES), latent heat (LH-TES), and thermochemical energy (TCS) as well as their application in European countries. With regard to future challenges, the installation of TES systems in buildings is being implemented at a rate of 5%; cogeneration application with TES is attested to 10.2%; TES installation in the industry sector accounts for 5% of the final energy consumption. From the market perspective, t... [more]

China has pledged that it will strive to achieve peak carbon emission by 2030 and realize carbon neutrality by 2060, which has spurred renewed interest in hydrogen for widespread decarbonization of the economy. Hydrogen energy is an important secondary clean energy with the advantage of high density, high calorific value, rich reserves, extensive sources and high conversion efficiency that can be widely used in power generation, transportation, fuel and other fields. In recent years, with the guidance of policies and the progress of technology, China’s hydrogen energy industry has developed rapidly. About 42% of China’s carbon emissions comes from the power system and Shenzhen has the largest urban power grid in China. Bringing the utilization of hydrogen energy into Shenzhen’s power system is an important method to achieve industry transformation, achieve the “double carbon” goal and promote sustainable development. This paper outlines the domestic and international development status... [more]

Gas hydrates are crystalline structures formed by water molecule cages hosting gas molecules [...]

The control of the curing temperature during the stem-drying stage is important for the quality of upper leaves of flue-cured tobacco. Based on the conventional curing process during the yellowing stage and the leaf0drying stage in the tobacco curing process, in this study, the dry-bulb temperature was increased to 72 and 75 °C in the bulk curing barn during the stem-drying stage to compare with the highest temperature of 68 °C commonly adopted in the bulk curing barn. The result showed that, compared with the conventional temperature setting, the energy consumption cost was reduced by 0.10 or 0.08 USD/kg when the curing temperature was increased to 72 or 75 °C, respectively. Statistical analysis showed that increasing DBT was beneficial to the improvement in the internal quality of flue-cured tobacco leaves. The adjustment of curing temperature also improved the aromatic quality and volume of singe-material tobacco leaves. However, as the temperature continued to increase, the quality... [more]

Semi-submersible offshore platforms play a vital role in deep-sea energy exploitation. However, the vast waves threaten the platform’s operation, usually leading to severe consequences. It is essential to study the wave-slamming mechanism of offshore platforms under extreme wave conditions. Existing research usually simplifies the offshore platform slamming problem. This paper establishes a model of a semi-submersible platform and a flexible mooring system in a numerical pool by means of the computational fluid dynamics (CFD) method. The distribution and the sensitivity of the slamming load on columns and deck in waves were investigated, and the model was verified through the basin test. Firstly, based on the Reynolds-averaged Navier−Stokes model, this study considers the volume-of-fluid method to track the free liquid level. After the column and floating body grid are locally refined, the slamming load under extreme regular wave impact is measured by measuring points on the column and... [more]

Optimizing coal blending is important for high-quality development of coking industries, among which deep understanding of relationships between coal characteristics and coke quality is critical. This work selected four typical coals from Shanxi Province in China to investigate influences of their structures and properties on coke quality. Although these samples belong to coking coals, the mechanical strength and thermal strength of the corresponding cokes are quite different. Macerals in coals, especially vitrinite, have significant effect on thermal strength of cokes. The thermal strength of coke B is better than coke A, because coal A mainly contains desmocollinite and coal B has more telocollinite. The CSR of coke B, C and D is higher than 60%, indicating they possess good thermal property. In the coking process, relatively low initial softening temperature (100 °C), smooth fluidity region and appropriate maximum fluidity is helpful to improve coke quality based on Gieseler fluidit... [more]

With the application and popularization of the Internet of Things (IoT), while the IoT devices bring us intelligence and convenience, the privacy protection issue has gradually attracted people’s attention. Access control technology is one of the important methods to protect privacy. However, the existing IoT access control technologies have extensive problems such as coarse-grainedness, weak auditability, lack of access process control, and excessive privileges, which make the security and privacy of our IoT devices face great threats. Based on this, a blockchain-based and encrypted currency-based access control model CcBAC supported by Trusted Execution Environment (TEE) technology is proposed, which can provide fine-graininess, strong auditability, and access procedure control for the Internet of Things. In this study, the technical principle, characteristics, and research status of the control model are introduced, and the framework of the CcBAC model is expounded in detail and for... [more]

Commercially pure aluminium is employed in several industrial applications. On some applications, the surface of this material needs to be functionalised. Laser surface texturing is a powerful tool to functionalise aluminium and aluminium alloy surfaces. However, the corrosion resistance of the laser textured aluminium alloy can be modified, and this has rarely been investigated in the literature. Consequently, the corrosion resistance of the laser textured commercially pure aluminium in saltwater was evaluated using several electrochemical techniques: asymmetric electrochemical noise, potentiodynamic polarisation curve and electrochemical impedance spectroscopy. Although the non-laser surface textured samples possessed higher kinetic corrosion resistance in the first hours of immersion, the corrosion mechanism (process group of the corrosion) was found to be more unstable than the laser textured specimens. The oxidised layer of the textured samples was also nobler than the native pass... [more]

This work seeks to contribute to the study of techniques for level control considering a nonlinear plant model. To achieve this goal, different approaches are applied to classical control techniques and their results are analyzed. Fuzzy Logic Control (FLC), Artificial Neural Network (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS), Model Predictive Control (MPC) and Nonlinear Auto-Regressive Moving Average (NARMA-L2) controllers are designed for the level control of a spherical tank. Subsequently, several tests and scenarios similar to those present in industrial processes are established, while the transient response of the controllers, their performance indices for monitoring the reference value, the rejection of disturbances, the presence of parameter uncertainties and the effects of noise are analyzed. The results show good reference tracking, with a settling time of approximately 5 s for 5 cm and a rise time of less than 4 s. No evidence for steady-state error or overshoot was... [more]

Hemp is a high-value crop that originated in Central Asia and is a historic but emerging cultivated plant. It may be grown for fiber, food, paper making, textiles, and therapeutic reasons. In the 21st century, market interest in hemp and its products has notably increased because seed portions can be utilized in the agri-food business, the woody component of the stem can be used in green buildings, the outer layer of the stems can be used in the textile industry, and the extraction of bioactive components from roots can play a vital role in the pharmacological industries. Hemp has recently been demonstrated to be a viable alternative for economies built on synthetic materials by the food, pharmaceutical, textiles, paper, building, and energy industries, among others. As a result, the goal of this study is to assemble the significant advancements in hemp, as well as to identify research gaps and research direction opportunities. The hemp plant will be provided more encouragement to be g... [more]

The technology for reproducing orchids in vitro has had to evolve due to the demand for these plants and the high cost of the biotechnology used due to the agar, the gelling agent. Consequently, research has tended to search for natural substitutes for agar. Our work describes the use of pectin and mucilage hydrocolloids extracted from the local waste matter of two species of Opuntia (O. ficus-indica and O. robusta) to study as a gelling agent in vitro culture media for Cattleya sp. These hydrocolloids were obtained by alkaline hydrolysis. Subsequently, these were used in proportions of 0.8%, 0.6%, 0.4%, and 0.2% in combination with agar to study the gelation time, texture profile analysis (TPA), seed germination under light and dark conditions, and a phenological study, including orchid analyses of leaves and roots, root and leaf length, seedling height, and width of the best-designed treatment were studied. Our results demonstrate that the treatment composed of 0.4% O. ficus-indica p... [more]

The purpose of this paper is to explore the impact of inventory turnover on the profitability level of Saudi manufacturers. The data comprises 78 manufacturers listed on the Saudi Stock Exchange and was used to test the research hypothesis. The related data over the 2017−2021 period were collected from annual reports and the Datastream database. After running a multiple regression analysis with a fixed effects model, findings showed that the higher the inventory turnover ratio, the higher the cost which could be suppressed, and the greater the profitability of a company. The outcomes of this study have significant implications for managerial accounting issues in the setting of Saudi Arabia. Further, they provide policy recommendations to decision makers and assist managers in enhancing sustainability in the manufacturing sector. This research is the first to investigate this relationship including the impact of COVID-19 among Saudi companies in several industries, thus filling a gap in... [more]

The new paradigm of nature-inspired cybersecurity can establish a robust defense by utilizing well-established nature-inspired computing algorithms to analyze networks and act quickly. The existing research focuses primarily on the efficient selection of features for quick and optimized detection rates using firefly and other nature-inspired optimization techniques. However, selecting the most appropriate features may be specific to the network, and a different set of features may work better than the selected one. Therefore, there is a need for a generalized pre-processing step based on the standard network monitoring parameters for the early detection of suspicious nodes before applying feature-based or any other type of monitoring. This paper proposes a modified version of the firefly optimization algorithm to effectively monitor the network by introducing a novel health function for the early detection of suspicious nodes. We implement event management schemes based on the proposed... [more]