Mulberry fruits (MF) contain many biologically active compounds beneficial for human health. In particular, in the literature, there are no studies on the kinetics of the freeze-drying of MF and the effect of the process temperature on the properties of dried fruits. The objective of this study was to ascertain how freeze-drying (FD) and air-drying temperature affected the kinetics of dehydration and chosen physicochemical parameters of MF. Both temperature and dehydration methods significantly influenced the drying rate and properties of MF. The Midilli model was the best fitted to the experimental data of the course of drying curves and with the lowest values of mean-square error. The highest lightness and yellowness were noted for freeze-dried fruit, whereas air-dried MF were characterized by the highest redness. An increase in drying temperature significantly changed the color of fruits and led to the degradation of L-ascorbic acid content. The highest content of L-ascorbic acid wa... [more]

Antibiotic pollution has become a serious concern due to the extensive use of antibiotics, their resistance to removal, and their detrimental effects on aquatic habitats and humans. Hence, developing an efficient antibiotic removal process for aqueous solutions has become vital. Amoxicillin (Amox) is one of the antibiotics that has been efficiently removed from an aqueous solution using hydroxyapatite nanoparticles (HAP NPs). The current study synthesizes and utilizes hydroxyapatite nanoparticles as a cost-effective adsorbent. Adsorbent dose, pH solution, initial Amox concentration, equilibrium time, and temperature are among the factors that have an evident impact on Amox antibiotic adsorption. The (200) mg dose, pH (5), temperature (25) °C, and time (120) min are shown to be the best-optimized values. The nonlinear Langmuir’s isotherm and pseudo-second-order kinetic models with equilibrium capacities of 4.01 mg/g are highly compatible with the experimental adsorption data. The experi... [more]

The World Health Organization promotes risk assessment and risk management through Water Safety Plans (WSPs) as the most effective way to manage drinking-water supplies. Despite proven advantages of this approach in other regions, WSPs are still not widely used across small drinking-water supplies in Sub Saharan Africa. The aim of this research is to identify good practices and related gaps which may assist with formal uptake of WSPs for small drinking-water supplies in Rwanda. Through semi-structured interviews with the key stakeholders involved in small drinking-water supply management across Rwanda, the aim is achieved through the investigation of the following: (i) current drinking-water management challenges; (ii) stakeholder collaboration and data management activities including reporting of information; and (iii) the regulatory and policy environment. The use and awareness of WSPs in Rwanda was confirmed as low. However certain drinking-water management activities which align wi... [more]

Renewable energy sources have become a significant alternative energy source due to the continuing depletion of conventional energy sources and fluctuation in fuel costs. Currently, wind energy is the foremost among all other renewable energy sources. However, modeling and analyzing industrial wind turbines is complex as the wind turbine power ratio and size have steadily increased. Undoubtedly, industrial wind turbines are huge and challenging to keep in research labs; simultaneously, exploring the controller/power converter performance is practically impossible. Therefore, to overcome the above drawbacks, wind turbine emulators have been developed to achieve the static and dynamic characteristics of wind energy conversion systems. This paper aims to present a comprehensive review of the different wind turbine emulators available in the literature. In addition, the implementation of real-time emulators is classified according to the structure and approaches. Furthermore, an extensive... [more]

In view of the problems of high acid consumption, the blockage of ore-bearing beds caused by iron ion precipitation and a low leaching rate in the conventional acid leaching of a sandstone-type uranium deposit, the author put forward “low-acid and oxygen leaching technology” research. In order to further clarify the mechanism of leaching sandstone-type uranium ore with low acid and oxygen, the oxidation mechanism of ferrous ion under acidic conditions, the influencing factors of ferrous ion oxidation process, the kinetic simulation of oxygen oxidizing uranium minerals, and the interaction of uranium and iron precipitation in acidic solution were analyzed and studied, and the mechanism of oxygen oxidizing uranium and uranium leaching under low acid conditions was explored. The results show that under the condition of low acidity, the kinetics that ferrous oxidized by oxygen is between the first-order and second-order reaction, which can reduce the iron ion precipitation and then reduce... [more]

The production of messenger ribonucleic acid (mRNA) and other biologics is performed primarily in batch mode. This results in larger equipment, cleaning/sterilization volumes, and dead times compared to any continuous approach. Consequently, production throughput is lower and capital costs are relatively high. Switching to continuous production thus reduces the production footprint and also lowers the cost of goods (COG). During process development, from the provision of clinical trial samples to the production plant, different plant sizes are usually required, operating at different operating parameters. To speed up this step, it would be optimal if only one plant with the same equipment and piping could be used for all sizes. In this study, an efficient solution to this old challenge in biologics manufacturing is demonstrated, namely the qualification and validation of a plant setup for clinical trial doses of about 1000 doses and a production scale-up of about 10 million doses. Usin... [more]

To address the problem of low integration and efficiency of reverse osmosis desalination system, an energy-recovery type incurve multiple acting pump is developed with integrated functions of a high-pressure pump, energy recovery device and booster pump. In order to determine its flow range and suppress cavitation generation, a mathematical model of the port plate is established, combining the realizable k-ɛ turbulence model and the Schnerr-Sauer cavitation model to obtain the internal flow field characteristics of the port plate. The effects of different rotational speeds and inlet pressures on cavitation were analyzed to obtain the gas volume fraction distribution rules. The design is based on the pressure and mass flow monitoring test device to verify the numerical calculation results. The results show that the experimental and simulation data match accurately, and with the increase in speed and the decrease in inlet pressure, the cavitation phenomenon becomes serious and the flow c... [more]

Hyperloop technology is a transport mode designed to move passengers anywhere in the world, using electric propulsion to carry passengers through a vacuum/near-vacuum tube for a maximum speed of 1200 km/h. Given this, governments, engineers, researchers, and billionaires have been racing over the past years to obtain the first operational system in the world off the ground and bring it from concept to reality. The paper aimed to maximize the capacity of the Hyperloop’s capsule and identify a suitable design of Hyperloop technology based on the different capacities and speeds of the capsules as well as the assumptions of the initial annual demand. Additionally, significant attention will be paid to the interior design of the capsules in which people travel to make the journey more comfortable and enjoyable. The design will be conducted in AutoCAD and Autodesk Revit models based on the allocation of different components such as capacity, compressor fan, batteries, compressor motor, etc.... [more]

The effect of temperature was studied on the synthesis of fatty acid alkyl esters by means of transesterification of waste beef tallow using ethanol and, iso-butanol and 1-butanol at supercritical conditions. These alcohols are proposed for the synthesis of biodiesel in order to improve the cold flow properties of alkyl esters. Alcohol−beef tallow mixtures were fed to a high-pressure high-temperature autoclave at a constant molar ratio of 45:1. Reactions were carried out in the ranges of 310−390 °C and 310−420 °C for ethanol and iso-butanol, respectively; meanwhile, synthesis using 1-butanol was assessed only at 360 °C. After separation of fatty acid alkyl esters, these samples were characterized by nuclear magnetic resonance (NMR) and gas chromatography coupled to mass spectrometry (GC-MS) to quantify yields, chemical composition, and molecular weight. Results indicated that yields enhanced as temperature increased; the maximum yields for fatty acid ethyl esters (FAEEs) were attained... [more]

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]