The Flight Environment Simulation System (FESS) at Altitude Ground Test Facilities (AGTF) is used to test aircraft engines. The FESS model is the basis of research and verification of advanced control algorithms. To further improve the steady and dynamic accuracy of the FESS model, a modeling method based on quasi-one-dimensional flow is proposed. Firstly, based on the unified inlet/outlet boundary specifications, the component models of test equipment, such as the quasi-one-dimensional flow model of pipe, the regulating valve model considering the heat transfer process, the multi-inlet and multi-outlet volume model reflecting the mixing characteristics of air flow, and the air source model and engine model, were established. Secondly, according to the real structure and working mechanism of the FESS, the above component models were used to build the numerical simulation model of the FESS. The simulation results showed that the relative deviation of mass flow and pressure were less tha... [more]

Oil fields in Romania were active in the period 1900−2020, some of which will close due to declining oil production and especially due to reduced processing after the application of European Community recommendations to give up fossil fuels and the use of renewable fuel. The rehabilitation of the soil affected by hydrocarbon pollution is carried out with public funds. This is why, when transferring the land to the local community, an oil pollution assessment study is carried out. If the hydrocarbon content is less than 1000 mg/kg dry matter, the soil is not depolluted. In the Moinesti oil area, Romania, against the background of the increased incidence of breast cancers in women who worked in oil facilities, a study was conducted on the natural radioactivity of abandoned oil areas. The results of this analysis are presented and discussed in this article. It is the first study of radioactivity of the oil tank farm affected by oil pollution, its purpose being to draw attention in detecti... [more]

Internet technology has provided an indescribable new way for businesses to attract new customers, track their behaviour, customise services, products, and advertising. Internet technology and the new trend of online shopping have resulted in the establishment of numerous websites to sell products on a daily basis. Products compete to be displayed on the limited pages of a website in online shopping because it has a significant impact on sales. Website designers carefully select which products to display on a page in order to influence the customers’ purchasing decisions. However, concerns regarding appropriate decision making have not been fully addressed. As a result, this study conducts a comprehensive comparative analysis of the performance of ten different metaheuristics. The ant lion optimiser (ALO), Dragonfly algorithm (DA), Grasshopper optimisation algorithm (GOA), Harris hawks optimisation (HHO), Moth-flame optimisation algorithm (MFO), Multi-verse optimiser (MVO), sine cosine... [more]

An integrated forward osmosis (FO)-membrane distillation (MD) process is promising for the treatment and resource recovery from municipal wastewater. As higher temperature is applied in MD, it could affect the performance of both FO and MD units. This study aimed to investigate the effects of the type of draw solution (DS) and feed solution (FS) such as ammonium solution or municipal wastewater containing ammonium at higher temperatures on membrane treatment performance. It is found that higher FS and DS temperatures resulted in a higher water flux and a higher RSF with either NaCl or glucose as DS due to the increased diffusivity and reduced viscosity of DS. However, the water flux increased by 23−35% at elevated temperatures with glucose as DS, higher than that with NaCl as DS (8−19%), while the reverse solute flux (RSF) increase rate with NaCl as DS was two times higher than that with glucose as DS. In addition, the use of NaCl as DS at higher temperatures such as 50 and FS at 42 °C... [more]

This study researched the effects of using various nitrogen (N) conservation measures on the residual characteristics of nitrate and ammonium N in soil and the associated N uptake by cotton plants. A field experiment with six treatments was conducted, as follows, no N application (DT1), conventional N application (DT2), 60% conventional N application combined with DCD (DT3), 60% conventional N application combined with NBPT (DT4), 60% conventional N application combined with cotton straw returning (DT5), and 60% conventional N application combined with DCD, NBPT, and cotton straw returning (DT6). The results showed that the cotton straws in the DT5 treatment were beneficial for the vegetative growth of cotton seedlings. However, it was observed that the later performance of the plants in this sample was poor in terms of height, biomass, and yield of cotton. The plant height in the DT6 sample increased by 15 cm compared with those in DT1, and the soil and plant analyzer development (SPA... [more]

Energy demand is increasingly the most relevant cost item in chemical plants. Operating expenses indeed play a main role in all plants processing large amounts of feedstock via well-established processes in the petrochemical industry. In staged operations, the optimal number of stages is usually obtained by means of an economic optimization. However, the designed equipment, external duties, and thus operating expenses may considerably vary under the effect of external disturbances. The main purpose of this paper is to outline a simple but effective procedure to account for perturbations in the assessment of the optimal number of stages. The analysis shows that appropriate investments could lead to a unit design able to mitigate the higher duty requirements when external perturbations occur. The results highlight that the optimal number of stages varies when uncertainty is considered and, with low computational effort, this can be effectively quantified by means of the applied methodolo... [more]

At the 2021 United Nations Climate Change Conference (COP26), many countries in the world agreed to reach the goal of net-zero greenhouse gas emissions by 2050. This issue constrains energy use, petrochemical use, and related manufacturing production patterns. It is undeniable that the diesel engine of large equipment is still widely used in engineering applications, and it will not disappear in a short time. Many industrial projects still have to face the use of diesel engines. This study was focused on the development of oil-producing microorganisms to generate lipids. The oleaginous yeast Rhodotorula mucilaginosa (R. mucilaginosa) was selected for liquid-state cultivation, and the conditions for growth of the yeast cells were assessed. For the liquid fermentation culture with a fixed inoculation amount of 5%, it was determined that a suitable oil-producing culture was obtained on the sixth day, and the optimum conditions involved a carbon source concentration of 60 g/L, a yeast extr... [more]

Post-consumer plastic management, otherwise termed waste plastic (WP) management, is a great challenge in today’s world, mainly because of its characteristic biodegradation properties. The quantity of waste plastics correspondingly increases with the increase in demand for plastic use. Research has shown that this demand increases yearly. Most of these waste plastics include high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET) and polystyrene (PS). Potentially, these wastes are a wealth, and studies have explored that pyrolysis is a reputable mechanism to accomplish this. In this critical review, an extensive investigation on waste plastics thermal pyrolysis (WPTP) is carried out. The factors that affect the product’s yield and selectivity are discussed, and a comparative quality guarantee of WPTP is examined. This paper presents an assurance into the current findings of WPTP and reveals some common gaps and misconceptions surrounding this... [more]

Spatiotemporal variations of oxygen concentration affect the cell behaviors that are involved in physiological and pathological events. In our previous study with Dictyostelium discoideum (Dd) as a model of cell motility, aggregations of Dd cells exhibited long-lasting and highly stable migration in a self-generated hypoxic environment, forming a ring shape that spread toward the outer higher oxygen region. However, it is still unclear what kinds of changes in the migratory properties are responsible for the observed phenomena. Here, we investigated the migration of Dd to clarify the oxygen-dependent characteristics of aerokinesis and aerotaxis. Migratory behaviors of Dd cells were analyzed under various oxygen concentration gradients and uniform oxygen conditions generated in microfluidic devices. Under hypoxic conditions below 2% O2, corresponding to less than 25 µM O2 in the culture medium, the migration of Dd cells was enhanced (aerokinesis) and the oxygen gradient guided the cells... [more]

The use of geothermal energy (GE) and the green economy in the environment of Slovak municipalities and towns is significant, due to the reduction in the negative influences and impacts of human society’s constant consumer lifestyle. The authors highlight the use of modern scientific knowledge, practical experience, and ever-improving technologies in the field of renewable energy sources RES. The aim of this contribution is to draw attention to the under-utilization of GE’s potential in Slovakia. Given the country’s commitment to meeting emission limits under EU carbon neutrality agreements by 2050, the use of this resource is very pertinent. Slovakia has significant geothermal resources that are not currently sufficiently utilized. The article suggests using GE to heat housing units of the housing estate near the geothermal source. Three scenarios (60 °C (pessimistic), 65 °C (conservative), and 70 °C (optimistic)) were considered in our energy balance and economic advantage calculatio... [more]

It is a concern that microplastics have been discovered in the food sources and water that we consume. This research was to evaluate the methods to isolate microplastics from organisms and how much of the environment of New Zealand (NZ), which is one of the least polluted countries, is contaminated by microplastics. New Zealand green-lipped mussels (Perna canaliculus) are considered to be an important product in the NZ food industry. For this reason, the existence of microplastics in these were investigated. Tarakihi fish (Nemadactylusmacropterus) consume food near the bottom of ocean, so this fish can be an indicator of the contamination of microplastics denser than water. In addition, bottled water, tap water and sea salt samples were also investigated. To isolate solid particles in an animal body, its tissues were chemically digested. It was found that 10% (w/w) potassium hydroxide (KOH) was a practical digestive protocol on biological tissues since polymers such as polyethylene ter... [more]

Grouting is a reinforcing method commonly used in underground engineering. The grouting-reinforced body is in saturated groundwater, which is due to long-term seepage, resulting in reinforcing performance attenuation. This is a guarantee for the safe operation of the underground structure’s long life cycle that obtains the performance attenuation law of the grouting-reinforced body under the action of seepage. This paper uses primitive to describe the mechanical properties of grouting-reinforced body under seepage erosion, establishing the damage mechanics model of grouting-reinforced body under seepage, designing deterioration experimental of grouting-reinforced body under seepage, studying the mechanism of the permeation water pressure on the permeability of the grouting-reinforced body, and obtaining the variable of the grouting-reinforced body damage variable with the permeation water pressure. Studies have shown that seepage effects have a “sudden jump” phenomenon in the process o... [more]

More rigorous environmental rules on hazardous metals release require the implementation of diverse methods to remove them from contaminated streams. The adsorption process is the most attractive method for removal of toxic metal ions from different aqueous solutions. In the present study, batch and fixed bed column experiments were carried out to investigate the performance of permethylated β-cyclodextrin impregnated resin for the removal of As(V) ions from aqueous solutions. Sorption of As(V) ions was performed in groups under a variety of pH and metal concentrations. It was noted that removal efficiency was the highest (98%) at pH 6.0, and at an initial As(V) concentration equal to 0.1 mg/L. Sorption model use for experimental data indicates that the removal mechanism of As(V) by the permethylated β-cyclodextrin impregnated resin was the physical sorption. The adsorption capacity of the cyclodextrin ligand immobilized onto Amberlite XAD-4 resin was 19 mg/g. In addition, the impregna... [more]

Here, we report a new two-step enzymatic polymerization strategy for the synthesis of poly(octamethylene suberate) (POS) using an immobilized Pseudozyma antarctica lipase B (IMM-PBLI). The strategy overcomes the lack of enzymatic POS synthesis in solvent-free systems and increases the final polymer molecular weight. In the first step, the direct polycondensation of suberic acid and 1,8-octanediol was catalyzed by IMM-PBLI at 45 °C, leading to the production of prepolymers with molecular weights (MWs) of 2800, 3400, and 4900 g mol−1 after 8 h in miniemulsion, water, and an organic solvent (cyclohexane: tetrahydrofuran 5:1 v/v), respectively. In the second polymerization step, wet prepolymers were incubated at 60 or 80 °C, at atmospheric pressure, in the presence of IMM-PBLI, and without stirring. The final POS polymers showed a significant increase in MW to 5000, 5800, and 19,800 g mol−1 (previously synthesized in miniemulsion, water, or organic solvent, respectively). FTIR analysis of... [more]

The trend of personalized medicine and the increasing flexibility of drug dosage relevant goals of the 21st century represent the foundation for the current research. To obtain doses smaller than the smallest available, physicians frequently write prescriptions for children and adults, without preserving the integrity of the pill. Moreover, patients purchase large amounts of medication for cost-saving reasons. To support the correct administration of the remedies and the partial alignment to the personalized treatment trend, this paper proposes a flexible and user-friendly solution for determining the medication quantity given to patients, using augmented reality and optical character recognition algorithm capabilities. Via the MATLAB development environment and a Logitech HD Pro C920 webcam, the results were 80% correct in identifying the cutting position of the pill, by means of the Hough transform, and 30% correct in weight recognition exploitation using an optical character recogni... [more]

The protection of human health and the environment (representing the main reason for waste management), as well as the sustainable use of natural resources, requires chemical, biological, physical and thermal treatment of wastes [...]

To study the distribution characteristics of typical pollutants in soil aggregates using different sieving methods, urban and arable soils were collected from Beijing and separated to different sizes by dry and wet sieving methods, to analyze present concentrations of inorganic chlorine and nine typical heavy metals (Cr, Mn, Co, Ni, Cu, Zn, Cd, As, and Pb). Results revealed that the distribution of wet-sieved aggregates was biased towards microaggregates (<250 μm), while the contrary result was found for the dry sieving method. Inorganic chlorine was more likely to be enriched in <53 μm fractions attained by both sieving methods. However, the content of inorganic chlorine in wet-sieved aggregates was significantly lower than in those that were dry sieved, which means the water’s effect on soluble ions was more pronounced. Heavy metals in urban soils were preferentially enriched in microaggregates no matter what kind of sieving method was applied. As for Mn and As found in agricul... [more]

Water hyacinth (WH) is a free-floating perennial aquatic plant that is considered a pest, due to its rapid grown rate and detrimental effects on environment and human health. It is nearly impossible to control WH growth, with mechanical extraction being the most acceptable control method; nevertheless, it is costly and labor-intensive. WH lignocellulosic biomass represents a desirable feedstock for the sustainable production of liquid fuels and chemical products. In this work, optimal conditions of thermochemical pretreatment for the release of reducing sugars (RS) from WH biomass were established: 0.15 mm of particle size, 50 g of dried solid/L of H2SO4 (3% w/v) and 20 min of heating time at 121 °C. Applying this pretreatment, a conversion of 84.12% of the hemicellulose fraction in the raw WH biomass into reducing sugars (277 ± 1.40 mg RS/g DWH) was reached. The resulting pretreated biomass of WH (PBWH) was enzymatically hydrolyzed by using six enzymatic complexes (all from Novozymes)... [more]

Biochar application in the agriculture sector is a practical approach to minimize waste and maintain sustainable farming. However, the information regarding biochar application in tea cultivation is limited and especially rare in field research. In this study, a two-year biochar experiment was conducted in a tea yard subject to tea yield and soil characteristics. According to tea growth, the tea yard for the experiment was divided into weak and normal sectors. Biochar was made from tea processing waste, mainly the twigs. The results showed that biochar application increased tea production by 2.3- and 1.3-fold in the weak and normal sectors, respectively, suggesting that converting tea waste to biochar for soil amendment is beneficial to increasing tea production, particularly in the weak sector. The regression analysis on tea production and soil characteristics revealed that only soil electric conductivity (R2 = 0.6597), soil organic matter (R2 = 0.7024), and soil extractable phosphate... [more]

This study used the EGSB and IC reactors to treat the high-salt and high-concentration organic wastewater (high-salt fatty acid production wastewater) and compared their performances The experimental results showed that the optimal influent water quality thresholds for both bioreactors to treat this wastewater were a COD concentration of 18,000 mg/L and a sulfate ion concentration of about 8000 mg/L. The reactor operated well when C/S was greater than 2.8. In addition, the value of C/S should not be less than 1.5. This is due to that under this condition, the sulfate reduction process has a significant impact on the removal of COD, and MPB may be inhibited by sulfides. The organic load OLR should not be greater than 10 kgCOD/(m3·d). It was also found that the start-up time of the IC reactor with external circulation was slightly shorter, and the COD removal effect, gas production rate, and load tolerance were slightly better than those of the EGSB reactor, the best reflux ratio of the... [more]

A degradation study of diazepam (DZP) in aqueous media by gamma radiation, high frequency ultrasound, and UV radiation (artificial-solar), as well with each process intensified with oxidizing agents (H2O2 and Fenton reagent) was performed. The parameters that influence the degradation of diazepam such as potency and frequency, irradiation dose, pH and concentration of the oxidizing agents used were studied. Gamma radiation was performed in a 60Co source irradiator; an 11 W lamp was used for artificial UV radiation, and sonification was performed at frequency values of 580 and 862 kHz with varying power values. In the radiolysis a 100% degradation was obtained at 2500 Gy. For the sonolysis, 28.3% degradation was achieved after 180 min at 862 kHz frequency and 30 W power. In artificial photolysis, a 38.2% degradation was obtained after 300 min of UV exposure. The intensification of each process with H2O2 increased the degradation of the drug. However, the best results were obtained by co... [more]

Several factors affect how particulate matter and gaseous emissions are formed during the combustion processes of biomass. The amount of combustion air, as well as its redistribution, is one of these factors. This article deals with the performance and emission parameters determined using different distributions of the amount of combustion air of the wood stove with beech wood as a fuel. Eighteen different settings of primary, secondary and tertiary air supplies were realized, while heat output, efficiency, particulate matter, carbon monoxide and nitrogen oxides were measured or determined. The aim of this article is to identify the optimal air distribution between primary, secondary, and tertiary air supplies focused on the mentioned parameters. Based on the results, two settings (25/50/25 and 0/100/0) could be the optimal variant. However, the concentration of particulate matter reached a higher value during the setting with a ratio of 25/50/25, similar to a ratio of 50/25/25. The me... [more]

This paper proposes a trading system (TS) based on a multicriteria decision aid (MCDA) process known as TODIM, (Multicriteria Interactive Decision Making) a Portuguese acronym for interactive and multicriteria decision-making. MCDA has been employed to solve financial questions because of its ability to deal with a complex environment populated with different sorts of criteria and alternatives, such as financial markets. The aim is to propose a general and adaptive tool for supporting the trading strategies of investors and market practitioners in such an environment. The reason for selecting TODIM among the different MCDA methods is that it is based on prospect theory, which assumes that the risk profile of the investor varies according to different situations, considering the risk of loss or gain. A list of simulations using some of the most prominent Brazilian stocks is performed, and the results are compared with the Buy-and-Hold benchmark and a TS based on an ensemble method for s... [more]

The pollution of aquatic ecosystems is a big problem that has its impact on river sediments. In recent decades, an effective solution to this problem has been the application of bioremediation technologies. Nanoremediation is an innovative part of these technologies. We still know little about the efficiency of nanoparticles, especially nanodiamonds, in modelled conditions. The aim of the present study is to investigate the effect of nanodiamonds on the key parameters of modelled bioremediation of river sediments that are polluted with phenol, as well their effect on the structures and functions of microbial communities. An important indicative mechanism that was used is the application of fluorescent in situ hybridization for sediment microbial communities. The results of this study revealed the positive role of nanodiamonds that is associated with their intoxication with high concentrations of phenol. Readaptation was also found, in which the xenobiotic biodegradation potential evolv... [more]

The intermittent heating mode of Kang plays an important role in the heat storage and release in cave dwellings. However, research on the effect of Kang heating on the thermal process of traditional buildings is rare. Therefore, based on long-term monitoring of cave dwellings, regular conclusions about the influence of Kang heating on the thermal environment were obtained. Furthermore, an unsteady heat transfer model of the envelope was proposed for the first time. Then, based on this model, the thermal storage performance of cave dwellings during the period of Kang intermittent heating was explored. The results showed that, due to Kang heating, the indoor air temperature of cave dwellings could be increased by an average of 3.1 °C. Furthermore, the inner walls had a large thermal mass and the maximum heat storage in a single day was 487.75 kJ/m2, while the maximum heat release was 419.02 kJ/m2. The heat release at night could reach 87%. In this paper, the law of thermal storage and re... [more]