High Fly Research Articles

The fly route of extended-spectrum-β-lactamase-producing Enterobacteriaceae dissemination in a cattle farm: from the ecosystem to the molecular scale

IntroductionThis study aimed to understand the origin and to explain the maintenance of extended-spectrum β-lactamase (ESBL) Enterobacteriaceae isolated from food-producing animals in a third-generation cephalosporin (3GC)-free farm.MethodsCulture and molecular approaches were used to test molecules other than 3GC such as antibiotics (tetracycline and oxytetracycline), antiparasitics (ivermectin, flumethrin, fenbendazol, and amitraz), heavy metal [arsenic, HNO3, aluminum, HNO3, cadmium (CdSO4), zinc (ZnCl2), copper (CuSO4), iron (FeCl3), and aluminum (Al2SO4)], and antioxidant (butylated hydroxytoluene) as sources of selective pressure. Whole-genome sequencing using short read (Illumina™) and long read (Nanopore™) technologies was performed on 34 genomes. In silico gene screening and comparative analyses were used to characterize the genetic determinants of resistance, their mobility, and the genomic relatedness among isolates.ResultsOur analysis unveiled a low diversity among the animal ESBL-producing strains. Notably, E. coli ST3268 was recurrently isolated from both flies (n = 9) and cattle (n = 5). These E. coli ST3268/blaCTX-M-15/blaTEM-1B have accumulated multiple plasmids and genes, thereby representing a reservoir of resistance and virulence factors. Our findings suggest that flies could act as effective mechanical vectors for antimicrobial gene transfer and are capable of transporting resistant bacteria across different environments and to multiple hosts, facilitating the spread of pathogenic traits. A significantly higher mean minimum inhibitory concentration of oxytetracycline (841.4 ± 323.5 mg/L vs. 36.0 ± 52.6 mg/L, p = 0.0022) in ESBL E. coli than in non-ESBL E. coli and blaCTX-M-15 gene overexpression in oxytetracycline-treated vs. untreated ESBL E. coli (RQOxy = 3.593, p = 0.024) confirmed oxytetracycline as a source of selective pressure in ESBL E. coli.DiscussionThe occurrence of ESBL E. coli in a farm without 3GC use is probably due to an as yet undefined human origin of Enterobacteriaceae blaCTX-M-15 gene transmission to animals in close contact with cattle farm workers and the maintenance of the local ESBL E. coli reservoir by a high fly diversity and oxytetracycline selective pressure. These findings highlight the critical need for stringent vector control to mitigate antimicrobial resistance spread for preserving public health. Addressing this issue necessitates a multifaceted approach combining microbial genetics, vector ecology, and farm management practices.

Solvothermal synthesis and adsorption performance of layered boehmite using aluminum chloride and high-alumina fly ash

High alumina fly ash (FAHAl) is a kind of bulk solid waste unique to China, whose availability of high-value aluminum and the threat to the environment make its high-value utilization urgent. In this work, the alumina containing leaching solution obtained from Na2CO3 roasting and HCl leaching of FAHAl was used as the mother liquor to prepare layered boehmite in situ. The preparation process with AlCl3 as the raw material was also compared. The formation process and mechanism of boehmite, the choice of solvent, along with the adsorption capability of Congo red were analyzed by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller method and adsorption experiments. Results showed that during the preparation of layered boehmite, the precursor Al(OH)3 from the reaction of Al3+ and OH– is transformed into boehmite γ-AlOOH. The existence of ethanol is beneficial to regulate and promote the growth of boehmite crystal effectively. When water and ethanol is mixed with a volume ratio of 2:1 and used as the solvent, the maximum specific surface area of the boehmite is obtained of 135.7 m2·g–1, and 99.16% of Congo red can be absorbed after 10 min when AlCl3 is used as raw material. As purified leaching solution is used as the mother liquid, the crystallinity of boehmite decreases slightly when the pH value decreases from 12.5 to 11. When pH is 11, the removal efficiency of Congo red reaches a maximum of 72.25%. This process not only achieves the extraction of aluminum and high-value utilization of FAHAl, but also provided a thought to prepare layered boehmite with adsorption properties.

Robust fuzzy-logic flight control for unmanned aerial vehicles (UAVs)

Researches on Unmanned Aerial Vehicles (UAVs) have been recently attracting considerable interest in the field of control theory applications. They are used in a wide range of areas thanks to having the potential of high manoeuvrability, hovering and flying, taking off and landing capabilities. However, to maintain robust control action towards changing conditions of the system is not an easy matter since quadrotor UAVs are highly unstable systems with high precision. Therefore, the main purpose of this study is to control a quadrotor UAV by using a proposed multi-input single-output (MISO) fuzzy-logic controller that ensures robustness if model parameters and trajectory change. For that reason, a 2-dimensional 3 degree-of-freedom quadrotor was used in this study to better evaluate the performance of proposed controller on UAVs. Afterwards, numerical analysis was performed and the findings were analysed. Consequently, the single most striking observation to emerge from the study is that the satisfactory results have been obtained demonstrating that the proposed fuzzy logic controller has remarkable advantage on the robustness of quadrotor UAVs.

Usability of the Combination of Fly Ash from Different Species

This article deals with the possible combination of high temperature fly ash with fluidised fly ash. The aim of this experiment is to verify the effect of the combination of these two energy by-products not only on the parameters of cement mortar in the fresh state, but especially on its mechanical parameters in the hardened state.

Influence of recycled steel fiber on the properties of self-compacting concrete with high fly ash content


 
 
 The recycled steel fibers from waste steel cables have properties suitable for enhancing the load-bearing capacity, impact resistance, and shrinkage reduction of Self-Compacting Concrete (SCC). The use of a high content of fly ash in SCC reduces production costs and is environment friendly by minimizing the amount of cement in the mix. This article presents the experimental research results on the influence of the content of recycled steel fibers on the properties of high-fly-ash SCC. The research utilized recycled steel fibers from elevator steel cables with volume percentages of 0%, 0.5%, 1% and 1.5% respectively in SCC, with a fly ash content in the SCC mix of 50% by volume of powder. The evaluated properties included workability, plastic shrinkage, drying shrinkage compressive strength, and tensile strength. The results indicate that using recycled steel fibers with a maximum content of 1% enables the production of SCC that meets European standards for workability. In addition, when comparing SCC with 0.5% and 1% recycled steel fiber content to control SCC samples (without steel fibers), the compressive strength of SCC increased by 5.04% and 7.56% respectively, the tensile strength increased by 2.99% and 5.97% respectively, plastic shrinkage decreased by 27.34% and 30.47% respectively, and 28-day drying shrinkage decreased by 3.2% and 4.6% respectively. Using recycled steel fibers combined with high-volume fly ash is a reasonable solution to save production costs and be environmentally friendly. Additionally, this solution not only improves the compressive and tensile strength but also limits plastic and drying shrinkage deformations of SCC. As a result, the durability of SCC is enhanced.
 
 

The role of supplementary cementitious materials and fiber reinforcements in enhancing the sulfate attack resistance of SCC/ECC composite systems

The purpose of this study is to investigate the effects of sulfate exposure on the mechanical behavior of fresh-to-fresh composite systems (CS), incorporating self-compacting concrete (SCC) in compression and engineered cementitious composites (ECC) in tension. ECCs were designed based on various supplementary cementitious materials (SCM) such as low and high calcium fly ash, slag and reinforcing fibers such as PVA and steel fibers. Repeated cycles of immersion in concentrated sodium sulfate solution were followed by drying at high temperatures (80 °C). After 90 and 180 days of cyclic exposure, the mechanical properties including flexural, compressive and tensile bond strength and mass change were evaluated. To investigate microstructural deterioration and reaction product concentration, SEM-EDS and backscattered electron imaging were used to examine sulfate profiles at the interfacial zone between SCC and ECC. Composite samples demonstrated excellent physico-mechanical resilience. The incorporation of low calcium fly ash and slag was observed to have a beneficial impact on residual mechanical properties in long-term exposures, along with the de-passivation capacity of the reinforcing fibers. No physical de-bonding was observed in any CS, however phase assemblages revealed high concentrations of reaction products in the SCC layers near the interfacial bond with the ECC layers.

Dysfunction of Nrf2-regulated cellular defence system and JNK activation induced by high dose of fly Ash particles are associated with pulmonary injury in mouse lungs

The mechanisms of the exposure to fine particulate matter (PM) as a risk factor for pulmonary injury are not fully understood. The transcription factor, NF-E2-related factor 2 (Nrf2), plays a key role in protection lung against PM insult and cancer chemoprevention. In this study, F3-S fly ash particles from a municipal waste incinerator were evaluated as a PM model. We found that F3-S triggered hierarchical oxidative stress responses involving the prolonged activation of the cytoprotective Nrf2 transcriptional program via Keap1 Cys151 modification, and c-Jun NH2-terminal kinase (JNK) phosphorylation at higher doses. In mouse lungs exposed to fly ash particles at a low dose (10–20 mg/kg), Nrf2 signalling was upregulated, while in those exposed to a high fly ash particle dose (40 mg/kg), there was significant activation of JNK, and this correlated with Nrf2 phosphorylation and the downregulation of antioxidant response element (ARE)-driven genes. The JNK inhibitor, SP600125, reversed Nrf2 phosphorylation, and downregulation of detoxifying enzymes. Silencing JNK expression in mouse lungs using adenoviral shRNA inhibited JNK activation and Nrf2 phosphorylation, promoted ARE-driven gene expression, and reduced pulmonary injury. Furthermore, we found that the 452–515 amino acid region within the Neh1 domain of Nrf2 was required for its interaction with P-JNK. We demonstrated that Nrf2 was an important P-JNK target in fly ash-induced pulmonary toxicity. JNK phosphorylated Nrf2, leading to a dysfunction of the Nrf2-mediated defence system.

Preparation of Silicon/Iron Binary Aerogel from High Iron Fly Ash and Adsorption of Mine Antimony Wastewater

Preparation of Silicon/Iron Binary Aerogel from High Iron Fly Ash and Adsorption of Mine Antimony Wastewater

Effect of Non-Class Fly Ash on Strength Properties of Concrete

Developing of green construction and reducing CO2emissions in the environment is a priority for industry in the coming years. Recycling fly ash in the concrete industry is a well-known way to reduce environmental impact. Aside from this benefit, there are numerous other positive effects of incorporating fly ash into concrete; however, in this research, the objective is to replace cement with a different percentage of non-class fly ash with high CaO, more than 42%. The analyzed variables are non-class fly ash properties, the effect of fly ash presence on the main properties of concrete and examining the optimum of non-class fly ash in ordinary concrete C-25/30 and high-performance concrete C-50/60. All investigations took place in the laboratory by producing 24 different mix designs and more than 1000 specimens to examine: consistency, setting time, shrinkage, and compressive strength in the short and long terms of curing. Recycling industrial waste in new construction, especially fly ash because of its non-uniform properties, still has some obstacles and is not a practical issue, but the future must be environmentally friendly, and this research proves that the objective of producing sustainable ordinary and high-performance concrete was achieved by replacing 40% of cement with non-class high CaO content fly ash. Doi: 10.28991/CEJ-2024-010-03-02 Full Text: PDF

Finite-Time Robust Flight Control of Logistic Unmanned Aerial Vehicles Using a Time-Delay Estimation Technique

This paper proposes a cascaded dual closed-loop control strategy that incorporates time delay estimation and sliding mode control (SMC) to address the issue of uncertain disturbances in logistic unmanned aerial vehicles (UAVs) caused by ground effects, crosswind disturbances, and payloads. The control strategy comprises a position loop and an attitude loop. The position loop, which functions as the outer loop, employs a proportional–integral–derivative (PID) sliding mode surface to eliminate steady-state error through an integral component. Conversely, the attitude loop, serving as the inner loop, utilizes a fast nonsingular terminal sliding mode approach to achieve finite-time convergence and ensure a quick system response. The time-delay estimation technique is employed for the online estimation and real-time compensation of unknown disturbances, while SMC is used to enhance the robustness of the control system. The combination of time-delay estimation and SMC offers complementary advantages. The stability of the system is proven using Lyapunov theory. Hardware-in-the-loop simulation and flight tests demonstrate that the control law can achieve a smooth and continuous output. The proposed control strategy can be effectively applied in complex scenarios, such as hovering, crash recovery, and high maneuverability flying, with significant practicality in engineering applications.

Fast setting and high early strength alkali-activated fly ash synthetized with pre-polymerized suspension combined with ultrafine fly ash at ambient temperature

Alkali-activated fly ash (AAFA) can offer both significant performance benefits and environmental advantages in corrosive and high-temperature environments. However, the slow setting and limited early strength development of AAFA at ambient temperature strict its use to pre-cast elements that must be cured using elevated temperatures. In order to address this limitation, this experiment pursued a distinctive approach to produce a pre-polymerized suspension (PPS) using ultrafine fly ash (UFA) that was activated with NaOH, thereby generating numerous nano-scale zeolite crystals and amorphous N-A-S-H gels. PPS was used alongside UFA in conjunction to create AAFA. Combining PPS in the AAFA mixture, while cutting UFA usage by 50%, led to a 30-minute initial setting time and a 15 MPa compressive strength after 3 days, which was significantly improved compared to the nearly 3 days required by the control sample to initially set. This remarkable result was attributed to the accelerated dissolution of active Si/Al ions from UFA, as well as the nucleation template effect of nano-scale zeolite and N-A-S-H gels within the PPS that speeded up the product's polyreaction, and resulted in a dense and quickly developed hardened structure. By using PPS, the dependency on UFA and its accompanying high energy consumption was dramatically reduced. Additionally, the fast-setting and high early strength properties of the optimized AAFA paste make it ideal for in-situ construction, thereby extending the usage of fly ash resources.

Numerical simulation of solidification of boiler molten ash impinging on vertical wall based on Smoothed Particle Hydrodynamics method

In order to study the whole process of the high temperature liquid slag fly ash produced after the combustion of high alkali coal as power coal in the boiler furnace, which moves in the furnace and impinges on the water wall, the heat exchange occurs and then the cooling phase transformation deposits and slags, and the possible factors of slagging particles are studied by changing the environmental variables. In this paper, based on Smoothed Particle Hydrodynamics (SPH), the dynamic behavior of boiler molten ash impacting vertical wall is studied, and the flow spreading and solidification model of molten slag impacting vertical wall is established. Thus, the process of phase change deposition of slag particles against wall is simulated. By observing the phase distribution of slag and the change in spreading process, the complete process of the slag particles hitting the wall, spreading, shrinking and solidifying is analyzed. Based on the cohesive and repulsive surface force method, a temperature-dependent surface tension model is established to simulate the effect of surface tension on flow characteristics when molten ash impinges on low-temperature vertical walls. The influences of slag impact velocity, initial temperature and water wall temperature on deformation and solidification heat transfer are discussed. The results show that the initial velocity and initial temperature of slag particles affect the phase change deposition velocity and the final spreading factor of slag, while the temperature of the water wall has little effect on the deposition deformation and solidification process of slag.

Study on the adsorption performance of modified high silica fly ash for methylene blue.

Presently, there are several issues associated with solid waste fly ash, such as its accumulation and storage, low comprehensive utilization rate, lack of high-value utilization technology, environmental risk and ecological impact. Thus, based on the high silica content and adsorption characteristics of fly ash, two novel adsorbents, namely mesoporous silica-based material (MSM) and sodium dodecyl sulfate-modified fly ash (SDS-FA), were prepared using an ultrasound-assisted alkali fusion-hydrothermal method and surface modification method. Furthermore, effects of adsorbent dosage, initial pH, contact time, and initial concentration of the solution on the adsorption of the organic pollutant methylene blue (MB) by fly ash, MSM, and SDS-FA were investigated to select the optimal modified high silica fly ash adsorbent. Based on the adsorption isotherms and adsorption kinetics, together with SEM, XRD, FTIR and BET analyses, the adsorption mechanism of MSM for MB was revealed. The results showed that under the conditions of an adsorbent dosage of 2 g L-1, initial pH of 9, contact time of 150 min, and initial concentration of 100 mg L-1, MSM and SDS-FA exhibited removal efficiencies of 92.69% and 84.64% for MB, respectively, which were significantly higher than that of fly ash alone. The adsorption of MB by MSM and SDS-FA followed the Langmuir model and pseudo-second-order kinetics, indicating monolayer adsorption with chemical adsorption as the dominant mechanism. The mechanism of the adsorption of MB by MSM is mainly the result of the synergistic effect among its increased specific surface area, hydrogen bonding, ion exchange, and electrostatic interactions. After five cycles of adsorption-desorption process, the removal efficiency of MSM for MB consistently remained above 80%. Therefore, MSM can serve as a valuable reference for the resource utilization of fly ash and remediation of dye-polluted wastewater.

OpenFOAM numerical simulation and experimental validation of high capacty long distance fly ash pneumatic conveying from a 620 MW thermal power plant

OpenFOAM numerical simulation and experimental validation of high capacty long distance fly ash pneumatic conveying from a 620 MW thermal power plant

Effect of Crushing Process Parameters on Quality of Fly Ash Aggregates Produced After Crushing High Strength Fly ash Blocks: A Laboratory Investigation

Effect of Crushing Process Parameters on Quality of Fly Ash Aggregates Produced After Crushing High Strength Fly ash Blocks: A Laboratory Investigation

Utilization of Coal Fly-Ash derived Silicon (Si) as Capacity Enhancer of Li-Ion Batteries Anode Material

The increasing demand for energy has caused a rise in coal usage, resulting in high fly ash generation. The high SiO2, Al2O3, and Fe2O3content in fly ashes (FAs) allow them to be processed in electrical energy storage technology, such as lithium-ion-based secondary batteries. The research aims to develop silicon from FAs for Li-ion battery applications. The fabrication of silicon materials employed in this study are (i) extraction of SiO2from FA, (ii) gelation of SiO2, (iii) magnesiothermic reduction of SiO2to Si under N2flow, (iv) purification of silicon, (v) the solid-state composite fabrication of Si/C. The as-prepared Si was characterized. XRD test showed the presence of silicon phase and minor impurities in Mg. SEM analysis of the Si showed that the material has a polymorph shape with a rough surface of micron-sized secondary particles. EDX test showed the presence of impurities in the form of O and Mg atoms; meanwhile, the EDX mapping confirmed the dominant distribution of Si in the sample. Galvanostatic charge-discharge analysis of a battery with 5%Si/C anode and LiNi0.8Co0.1Mn0.1O2or NCM811 cathode resulted in a specific charge and discharge capacity of 600 mAh/g and 473.6 mAh/g, respectively, which is greater than the graphite theoretical capacity of 372 mAh/g.

Liquid membrane coupled electrodialysis system for highly-efficient lithium recovery from fly ash acid leaching solution

Recovering lithium (Li) from high Li-bearing coal fly ash (CFA) is a challenging task due to CFA's complexity and minor content of Li. Acid leaching is a common treatment, but it faces the difficulties of complex leaching solution and selective separation of Li+. This work evaluated a liquid membrane coupled with the electrodialysis (LME) system to separate Li+ from the CFA leach liquor. The liquid membrane (LM) performs as an ion carrier to selectively transport Li+, while the electric field can drive the ion migration. The results show that the LM TBP+[HOEmim][NTf2] (v/v, 5:5) exhibits the best recognition and releasing ability toward Li+. The selective migration of Li+ can be achieved in acidic environment in the presence of concentrated Al3+. The Al/Li ratio decreases from 30 of the feed to 0.55 in the receiving solution after 12 h at 3 V. The practical application in the CFA leach liquor indicates that the system has preferential selectivity for transmembrane transport of Li+, while other multivalent ions were mostly hindered. This work presents a new idea for Li recovery from the solid waste residues, and offers a deep insight into the separation of valuable metal ions from complex solutions.

Properties of high calcium fly ash geopolymer incorporating recycled brick waste and borax

Geopolymer has attracted various interests all around the world since its introduction. It is known as a beneficial alternative to cement as it can be produced at room conditions, effectively cutting down CO2 emissions compared to the high temperature calcination process in cement production. Moreover, industrial waste or by-products can be upcycled by incorporating as the precursor in geopolymer production, reducing the environmental burden of waste disposal. High calcium fly ash is emerging as a viable option to produce geopolymer binder material. Recycled brick waste (RBW) on the other hand, may be a good source of aluminosilicate, which is vital to produce geopolymer binder material. However, the incorporation of both materials in the production of geopolymer binder materials has not been well-studied. Hence, this paper presents a study on the properties of geopolymer mortar made with high calcium fly ash incorporating 10 % RBW and borax additive at dosages of 3 % and 6 %. In the fresh state, the geopolymer with 10 % RBW and higher borax dosage had a lower temperature, but all mixes gradually exhibited a similar temperature range between 31.3 °C and 31.9 °C. The geopolymer containing RBW exhibited a 13 % higher compressive strength compared to the RBW-absent counterpart in both mixes with 3 % and 6 % borax while the inclusion of borax from 3 % to 6 % reduced the compressive strength by 22 %. The geopolymer had compressive strengths of about 11.8–15.9 MPa after prolonged exposure to an acidic solution, showing a decreasing trend due to the acid attack on the reaction products. The geopolymer mixes containing 6 % borax exhibited lower strength loss (30.2 % and 28.2 %) compared to those with 3 % borax (40.3 % and 42.3 %) on 800 °C heat resistance while the effect of RBW was negligible. On the other hand, the drying shrinkage of geopolymer did not benefit from the inclusion of either RBW or higher borax dosage. The study provided important insights into the incorporation of these materials in the properties of the geopolymer.

Characterization of genetic variability among sorghum genotypes by morphological descriptors associated with high yield and shoot fly resistance

Characterization of genetic variability among sorghum genotypes by morphological descriptors associated with high yield and shoot fly resistance

Preparation of lightweight and high-strength ceramsite from highly doped coal fly ash

A method for producing lightweight and high-strength ceramsite from coal fly ash was presented. It provides a potential solution to the problem of coal fly ash stockpiling and makes effective use of SiO2, Al2O3 and other substances. Based on the thermodynamic analysis, an optimized method for the preparation of lightweight high-strength ceramsite by sintering at high coal fly ash doping (60%–90%, mass fraction) was designed. The mineral transformation in the complex silicate systems was studied. The cooling method, the roasting process and the raw material formula were improved. At the roasting temperature of 1200 °C and the holding time of 5 min, the density of the ceramsite produced was less than 0.93 g/cm3 and the strength was as high as 1.08 kN. The specific strength of ceramsite produced by this approach was significantly higher than that of several randomly purchased ceramsite products in the market.