Periodica Polytechnica (Budapest University of Technology and Economics)
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Green Synthesis of 2-isonicotinoyl-4,6-dihydroimidazo[4,5-c] Pyrazol-5 (2H)-one Derivatives via One-pot Multicomponent Approach as a Potent Antifungal Agent
Get PDFIn the present research work, we made an effort to a green, efficient, and simple procedure for the one-pot multicomponent synthesis of novel 2-isonicotinoyl-4,6-dihydroimidazo[4,5-c] pyrazole-5 (2H)-one derivative in presence of environmentally sustainable PEG-400 reaction medium and recyclable catalyst bleaching earth clay (pH 12.5, 10% by weight). The benefits of this methodology include a quick reaction time, high product yield, and an easy work-up procedure. The antifungal potency was studied for synthesized derivatives using the agar well diffusion method against Aspergillus niger (MTCC280), Aspergillus flavus (MTCC3008), and Penicillium citrinum fungus strain. Among the tested compounds six from the nine compounds show promising antifungal activity among the tested compounds. The derivatives were characterized using 1H NMR, 13C NMR, Mass, and IR spectroscopic methods. Molecular docking study 2-isonicotinoyl-4,6-dihydroimidazo[4,5-c] pyrazole-5 (2H)-one derivative was conducted against the PDB : 3KHM, 14 α-demethylase (CYP51) from Trypanosoma cruzi in complex with inhibitor fluconazole protein and PDB : 6UW2 clotrimazole bound complex of Acanthamoeba castellanii CYP51
Evaluation of the Plant Growth Promoting Effect of Root Contact, Diffusible and Volatile Compounds Produced by Rhizobacteria and Microalgae on Arabidopsis Thaliana
Get PDFBacteria and microalgae have beneficial impact on plant growth and survival through host functional and adaptive traits via complex mechanisms. Volatile and non-volatile metabolites produced by microorganisms have a continuous effect on plants by providing nutrients and regulating various plant metabolic and signaling pathways. The aim of this study was to assess the plant promoting effect of two Chlorella spp. microalgae under mixotrophic conditions, as well as the effects of plant growth promoting rhizobacteria (PGPR) Bacillus sp. WCC-B36, Azospirillum sp. WCC-ASP12 and Azotobacter sp. WCC-IZA56 on the model plant Arabidopsis thaliana. Growth and quality parameters were followed in three different co-cultivation systems as (i) direct root contact supplemented with density effect, (ii) contact with diffusible compounds and (iii) effects of volatile compounds. Direct effect mediated by rhizobacteria promoted significant shoot and root length growth with well-developed root architecture at low bacterial densities (<105 CFU – colony forming unit mL−1), which became more pronounced over time. At a higher microbial density (>107 CFU mL−1), plant growth was retarded regardless of the bacteria present. This suggests that the microenvironment surrounding the colonies was altered and there was competition for nutrients. Our results indicate that the metabolites, diffusible and volatile organic substances produced by the microalgae enhanced lateral root growth and root hair formation, while inhibited primary root elongation. Volatile and diffusible substances of Chlorella sp. CHL13 and Bacillus sp. WCC-B36 have the most significant effect on seedlings and primary root growth
Biodegradation of Plastic Wastes in Soil: A Review on Testing and Evaluation Procedures
Get PDFThe recalcitrant behaviour of plastic creates an acute pollution on soil and aquatic biota. The plastic polymer synthesised from petroleum takes several hundred years to degrade. During excavation activities on the lands within or at the outskirts of urban limits, single use plastic wrappers and bags that were buried long ago, can be found in large quantities. Researchers have already identified the potentiality of microorganisms to biodegrade the plastic polymers. These microorganisms utilise plastic as a sole source of carbon and mineralise them into carbon dioxide under optimum environmental conditions. This paper provides a brief review on the biodegradation studies carried out by various researchers, spectra of microorganisms identified with the potential to degrade various polymeric substances, methods of testing and evaluations in order to quantify the effectiveness of degradation, their shortfalls and risks involved in implementing bioremediation technique in the field. A review on other related aspects that are deemed to be relevant to this topic are also discussed
Study and Optimization of a New Perovskite Solar Cell Structure Based on the Two Absorber Materials Cs2TiBr6 and MASnBr3 Using SCAPS 1D
Get PDFThe main objective of this study is to optimize the photovoltaic parameters of a new perovskite solar cell structure (PSC) suggested, using the simulator solar cell capacitance simulator-one dimension (SCAPS-1D) which aims to improve its performance by adjusting different key variables. This new suggested cell which consists of six materials represents the major innovation point of our research, it is distinguished by a double active layer, composed of the two-cesium titanium hexabromide (Cs2TiBr6) and methylammonium tin tribromide (MASnBr3) perovskites. Using the SCAPS 1D software, the simulation allows to determine the optimal values of the various parameters to maximize the efficiency of the PSC. First, the effect of the thickness and defect densities of both Cs2TiBr6 and MASnBr3 materials on the output parameters was studied as well as the defect density in the interfaces. Subsequently, the doping density in Cs2TiBr6 and MASnBr3 was also optimized. Finally, the impact of temperature, series resistance and shunt resistance were evidenced. The results indicate that precise adjustments of these parameters can lead to significant improvements in photovoltaic performance, such as open circuit voltage of 1.105 V, short-circuit current density of 33.90 mA cm−2, fill factor of 88.01% and power conversion efficiency (PCE) 32.96%. These performances were obtained for a thickness of 700 nm for Cs2TiBr6 and 900 nm for MASnBr3, a defect density of 1014 cm−3 for each absorber layer, a defect density of 1014 cm−2 for each interface and a doping density of the order of 1018 cm−3 for each absorbent layer
Modified Koufopanos' Mechanism in the Kinetics of in-situ Catalytic Pyrolysis of Co-pelletized Rice Husks and Ash
Get PDFUsing rice husk ash as a cheap in-situ catalyst under certain pyrolysis operating conditions can affect the yield of rice husk pyrolysis products. The two-stage semi-global kinetic models were often used to predict these yields. This research aims to study the effect of rice husk ash catalyst addition, heating rate, and pyrolysis temperature on the kinetics and yield of rice husk pellet pyrolysis products. A modified kinetic model of the Koufopanos mechanism was proposed to predict the product's yield. The apparent pyrolysis kinetics were analyzed with the assistance of a self-designed macro-thermogravimetric analysis apparatus. The co-pelletized rice husk and ash were heated from 303 to 873 – 1173 K at 5, 10, and 40 K/min heating rates in a N2 environment. Gas was collected and analyzed with gas chromatography equipped with a thermal conductivity detector at several temperature intervals during pyrolysis. It was found that the yield of the pyrolysis products can be described well by the proposed kinetic model. Adding a rice husk ash catalyst at 10 K/min reduced the activation energy of the primary gas and tar formation. It also enhanced the secondary pyrolysis reactions to form gas, which occurs more significantly at higher temperatures and heating rates. At low heating rates, heterogeneous secondary reactions tended to convert the primary tar into secondary gas. However, secondary reactions converted the primary tar into secondary tar at higher heating rates. On the other hand, increasing the pyrolysis temperature increased the gas yield and reduced the yield of tar and char
Stiffness of Loaded Face of Steel Rectangular Hollow Section Columns with and without Concrete Infill in Beam-column Endplate Connections
Get PDFThis paper presents a new analytical approach for calculating the stiffness of the loaded face of a rectangular hollow section RHS column in beam-column connections with and without concrete infill, as well as with flush and extended endplates, to determine the behavior curve of these types of connections. The approach, based on Eurocode 03's component method, offers efficient analytical formulas for accurately determining the loaded face's stiffness. A comparison with existing methods demonstrates its remarkable simplicity and efficiency, allowing a simple beam model to represent the RHS column's behavior with all relevant parameters considered. Comparison of the new approach to existing ones from the literature demonstrates their reliability and efficiency. Furthermore, when compared to 32 experimental tests presenting nearly the entire range of probable connection configurations, as well as attachment techniques commonly used in construction practice, the margin of error does not exceed 12 percent on average and a maximum of less than 25 percent
Study on a 3D Train-Track-Bridge System Dynamic Behavior Subjected to Over-Height Collision Force
Get PDFRailway bridges are built to allow trains to cross over highways, valleys, or other transportation infrastructure. In recent years, the number of railway bridges subjected to over-height collision forces has increased. These collisions damage the bridge and affect the safety of the running train. In this investigation, first, a 3D GT26 train-track-bridge interaction model was created to study the effects of collision forces applied to the bridge superstructure and not to the bridge piers as a novelty of this research using the finite element analysis. Then, the dynamic responses of the railway bridge due to the GT26 train load and subjected to over-height collision forces were obtained. Finally, the different sensitivity analyses describe that changing the length of the collision area, the bridge span, and the value of collision forces affect the dynamic responses of the bridge in the contact area. The results show that maximum lateral displacement of the concrete girder in case of assuming the GT26 train 3D model plus over-height collision force is 8.88% less than the case in which considering only freight train axle-load and same over-height collision force apply to the bridge superstructure, and its value reduces from 45 mm to 41 mm. The maximum lateral displacement of the bridge deck is reduced by about 71% by increasing the collision area length from 0.2 m to 1.2 m and at the impact area rises about 43.5% by changing collision speed from 48 km/hr to 144 km/hr as collision force from 7753 kN to 13370 kN
A Simple Differential Evolution with Random Mutation and Crossover Constants for Constrained Optimization
Get PDFThe article proposes a simple version of the differential evolution algorithm (abbreviated as sDE) in which the mutation factor and crossover constant are chosen randomly in the range (0,1) during the search for the optimal solution. The sDE is the same as the original version of the differential evolution algorithm, except the user does not have to choose the best values of mutation constant and crossover constant for each optimization problem. Therefore, the optimization process is now very simple as it remains only one parameter (i.e. the population size) in the algorithm, besides the stopping criterion (e.g. number of iterations). It also consumes less computation time than the original differential evolution as it is not necessary to tune the mutation and crossover constants. In this study, the proposed technique is applied to three constrained optimizations, three engineering design problems, and six planar and spatial trusses under frequency constraints. Despite the very simple characteristics of the proposed technique, sDE gives promising results in comparison with other results in the literature
Optimizing Foamed Bitumen Bound Asphalt Mixture Design Using Neural Network
Get PDFEffective design of bituminous mixes for road pavements requires a robust understanding of their mechanical properties to ensure durability and safety. Conventional experimental methods for assessing these properties are time-consuming and costly. To address this challenge, advanced machine learning techniques have gained prominence in predicting bituminous mix behaviour. In this study, we focus on predicting Marshall Stability (MS) and Flow (MF) of foamed bitumen bound asphalt pavements using essential input parameters: Temperature, Foam Content, Expansion Ratio, and Half-Life. Leveraging a neural network model, accurate prediction equations and surface analyses were developed for optimizing pavement design. Furthermore, integration equations are also introduced to enhance the accuracy of the methodology. Sensitivity and Parametric Analyses provide insights into parameter impacts, and R-squared measures model goodness of fit. The research work presented not only streamlines pavement design but also advances the understanding of intricate input-output relationships in bituminous mixtures
Numerical Procedure for Solving the Nonlinear Behaviour of a Spherical Absorber
Get PDFThe aim of the paper is to perform numerical simulations for a system of nonlinear differential equations that describe the behaviour of a spherical absorber placed in a support bowl and to describe the applied techniques. The motion of the sphere is constrained to a plane problem. The derived system of equations is numerically solved using the continuation method and the modified secant method. The absorber's response to different harmonic excitation forces is simulated to demonstrate the applicability of these techniques in its analysis. The dependence of the response amplitude on the angular frequency of excitation is presented graphically. The results also include a response stability analysis using the Routh-Hurwitz criteria