According to regulations from the International Maritime Organization (IMO), the sulfur content of vessels must not exceed 0.5% outside the Emission Control Areas (ECAs) starting from 2020. The marine exhaust gas desulfurization (De-SOx) system is the most feasible technology to meet the increasing regulations, but there is always a large swirl at the bottom of the scrubber causing uneven flow past the sprays. Solving this problem by adjusting the spray is a feasible method. The exhaust gas at 485 K and injection liquid at 305 K are simulated to optimize the flow field in a De-SOx scrubber. The results indicated that the flue gas was easily concentrated in the left side area of the scrubber and this part of hot gas could escape from the scrubber. By controlling the nozzles distribution and the nozzles angle, it was possible to reduce the droplets to hit the wall and improve the utilization rate of the washing liquid. The nozzles were arranged up and down in different positions, which r... [more]

The maximum performance of microbial fuel cells (MFCs) is significantly affected by the reduction reactions in the cathode, but their optimum condition is not fully understood yet. The air-cathode MFC operations with different separators (Nafion 117 and polypropylene (PP80) were evaluated at various relative humidity (RH) at the cathode chamber. Air cathode MFCs with a Nafion 117 separator at RH of 90 ± 2% produced the highest cell voltage of 0.35 V (600 Ω) and power density of 116 mW/m2. With a PP80 separator, the maximum power generation of 381 mW/m2 was obtained at a relatively lower RH of 30 ± 2%. The cyclic voltammogram and Tafel analysis indicated that the best performance of cathodic oxygen reduction reactions could be observed at 90% RH for Nafion and 50% RH for the PP80 separator. Additionally, the RH conditions also affected the anodic reactions and oxygen mass transfer rates to the anode chamber through the cathode and separators. This study suggests that the optimum RH cond... [more]

The molecular recognition capability of naturally occurring biomolecules is generally expressed against biomolecules in the biological milieu. Recently, it was demonstrated that the specific interactions of biomolecules such as short peptides were applicable to artificial materials. We have developed peptides with specific affinities for synthetic polymers toward functional biocomposite polymeric materials. In this study, we demonstrated the preparation of biocomposite nanoparticles composed of poly(propylene oxide) (PPO) and PPO-binding peptides. A simple injection of a concentrated PPO solution dissolved in an organic solvent into the peptide solution under sonication resulted in the formation of nanospherical structures. Morphological observation indicated characteristic softness and high applicability as a molecular carrier of the biocomposite nanoparticles. Structural characterization of PPO and the PPO-binding peptide revealed the structural conformability of these molecules to i... [more]

This study demonstrates the effects of structural variations of lignins isolated via an organosolv process from different woody and herbaceous feedstocks on their thermal stability profiles. The organosolv lignins were first analysed for impurities, and structural features were determined using the default set of gel permeation chromatography, FT-IR spectroscopy, quantitative 31 P NMR spectroscopy and semi-quantitative 1 H- 13 C HSQC analysis. Pyrolysis-, O 2 - and CO 2 -reactivity of the organosolv lignins were investigated by thermogravimetric analysis (TGA), and volatile formation in various heating cycles was mapped by head-space GC-MS analysis. Revealed reactivities were correlated to the presence of identified impurities and structural features typical for the organosolv lignins. Data suggest that thermogravimetric analysis can eventually be used to delineate a lignin character when basic information regarding its isolation method is available... [more]

Two new anticancer-active 1,2,3-triazole-dipyridothiazine hybrids were evaluated for their lipophilicity using thin-layer chromatography (TLC) and computational methods. The experimental lipophilicity was evaluated with mobile phases (mixtures of TRIS buffer and acetone), exploiting a linear correlation between the retention parameter (RM) and the volume of acetone. The relative lipophilicity parameter (RM0) was obtained by extrapolation to 0% acetone concentration. This parameter was intercorrelated with a specific hydrophobic surface area (b) revealing two congeneric subgroups: hybrids of 1,2,3-triazole-2,7-diazaphenothiazines and 1,2,3-triazole-3,6-diazaphenothiazines. The parameter RM0 was converted into the absolute lipophilicity parameter logPTLC using a calibration curve prepared on the basis of compounds of known logP values. Triazole−dipyridothiazine hybrids turned out to be medium lipophilic with logPTLC values of 1.232−2.979. The chromatographically established parameter log... [more]

Each year, the food supply chain produces more than 1.3 billion tons of food and agricultural waste, which poses serious environmental problems. The loss of the massive quantity of secondary and primary metabolites retrievable from this resource is a significant concern. What if there is a global solution that caters to the numerous problems arising due to the humongous volume of waste biomass generated in every part of the world? Insects, the tiny creatures that thrive in decaying organic matter, which can concentrate the nutrients present in dilute quantities in a variety of by-products, are an economically viable option. The bioconversion and nutritional upcycling of waste biomass with insects yield high-value products such as protein, lipids, chitin and frass. Insect-derived proteins can replace conventional protein sources in feed formulations. Notably, the ability of the black soldier fly (BSF) or Hermetia illucens to grow on diverse substrates such as agri-food industry side str... [more]

Bulk, solventless anionic ring-opening polymerization (AROP) of ε-caprolactam (CPL) with high yields, without side products and with short reaction times, initiated by caprolactamate-carbamoylcaprolactam initiating systems belong to green polymerization processes, leading to poly(ε-caprolactam) (Polyamide 6, PA6, Nylon 6). However, the effect of post-polymerization heat (i.e., slow, technically feasible cooling) on the fundamental characteristics of the resulting polymers such as yield and molecular weight distributions (MWDs) have not been revealed thus far. Significant post-polymerization effect was found by us in terms of both monomer conversions and MWDs by carrying out CPL polymerization with industrial components under conditions mimicking thermoplastic reaction transfer molding (T-RTM). Remarkably, higher monomer conversions and molecular weights (MWs) were obtained for Polyamide 6 samples prepared without quenching than that for the quenched polymers at the same reaction times.... [more]

The availability of predictions of future system inputs has motivated research into preview control to improve set-point tracking and disturbance rejection beyond that achievable via conventional feedback control. The design of preview controllers, typically based upon model predictive control (MPC) for its constraint handling properties, is often performed in a monolithic nature, coupling the feedback and feed-forward problems. This can create problems, such as: (i) an additional feedback loop is introduced by MPC, which alters the closed-loop dynamics of the existing feedback compensator, potentially resulting in a deterioration of the nominal sensitivities and robustness properties of an existing closed-loop and (ii) the default preview action from MPC can be poor, degrading the original feedback control performance. In our previous work, the former problem is addressed by presenting a modular MPC design on top of a given output-feedback controller, which retains the nominal closed-... [more]

Since many studies on axial piston pumps aim at enhancing their high power-weight ratio, many researchers have focused on the generated mechanical losses by the three friction pairs in such pumps and attempted to diminish them through abundant and new structural designs of the pump’s components. In this paper, a high-speed 2D piston pump is introduced and its architecture is specifically described. Afterward, a mathematical model is established to study the pump’s mechanical efficiency, including the mechanical losses caused by the viscosity and stirring oil. Additionally, in this study the influences of the rotational speed, the different load pressures, and the rolling friction coefficient between the cone roller and the guiding rail are considered and discussed. By building a test rig, a series of experiments were carried out to prove that the mechanical efficiency was accurately predicted by this model at low load pressures. However, there was an increasing difference between the t... [more]

Digestate, as an urban solid waste, was considered as an innovative adsorbent for colorant polluted wastewater. Batch adsorption experiments were carried out using digestate as an adsorbent material to remove various dyes belonging to different categories. The removal rate and adsorption capacity of dyes were evaluated and the dose of digestate, contact time, and initial dye concentration were studied. The maximum removal rate was approximately 96% for Methylene Blue. The equilibrium time for the Methylene Blue was 4 h, while for other dyes, a longer contact time was required to reach the equilibrium. The suspicion of colloidal matter release into the solution from solid fraction of the digestate led to the investigation of the consequence of a washing step of the digestate adsorbent upstream the adsorption experiment. Washed and not washed adsorbents were tested and the differences between them in terms of dye removal were compared. Moreover, experimental data were fitted by pseudo-fi... [more]

Bioprocesses can be found in different areas such as the production of food, feed, energy, chemicals, and pharmaceuticals [...]

This work aims at modeling in detail the polymerization of non-ionized acrylic acid in aqueous solution. The population balances required to evaluate the main average properties of molecular weight were solved by the method of moments. The polymerization process considered is initiated by a persulfate/metabisulfate redox couple and, in particular, the kinetic scheme considers the possible formation of mid-chain radicals and transfer reactions. The proposed model is validated using experimental data collected in a laboratory-scale discontinuous reactor. The developed kinetic model is then used to intensify the discontinuous process by shifting it to a continuous one based on a tubular reactor with intermediate feeds. One of the experimental runs is selected to show how the proposed model can be used to assess the transition from batch to continuous process and allow faster scale-up to industrial scale using a literature approach.

We address the question of how to reduce the inevitable loss of performance that is incurred by robust multi-stage NMPC due to the lack of knowledge compared to the case where the exact plant model (no uncertainty) is available. Multi-stage NMPC in the usual setting over-approximates a continuous parametric uncertainty set by a box and includes the corners of the box and the center point into the scenario tree. If the uncertainty set is not a box, this augments the uncertainty set and results in a performance loss. In this paper, we propose to mitigate this problem by two different approaches where the scenario tree of the multi-stage NMPC is built using sigma points. The chosen sigma points help to capture the true mean and covariance of the uncertainty set more precisely. The first method computes a box over-approximation of the reachable set of the system states whereas the second method computes a box over-approximation of the reachable set of the constraint function using the unsc... [more]

Hydrodesulfurization (HDS) has been commercially employed for the production of ultra-low sulfur fuel oil. However, HDS is unable to remove sterically hindered sulfur-containing compounds such as dibenzothiophene (DBT) and benzothiophene (BT). An alternative way to remove sulfur is via extractive desulfurization system (EDS) using deep eutectic solvents (DES) as sustainable extractant. In this work, liquid polymer DES was synthesized using tetrabutylammonium chloride (TBAC) and poly(ethylene glycol) 400 (PEG) with different molar ratios. Response surface methodology (RSM) was applied to study the effect of independent variables toward extraction efficiency (EE). Three significant operating parameters, temperature (25−70 °C), DES molar ratio (1−3), and DES volume ratio (0.2−2.0), were varied to study the EE of sulfur from model oil. A quadratic model was selected based on the fit summary test, revealing that the extraction efficiency was greatly influenced by the amount of DES used, fol... [more]

The effect of bacteria (Bacillus clausii) addition on the culturability and antioxidant activity of resveratrol prepared by spray drying was studied in this work. Inulin and lactose were employed as carrying agents and their performance compared. Resveratrol microencapsulated in inulin showed the highest antioxidant activity (26%) against free radicals. The co-encapsulated materials (bacteria and resveratrol) in inulin and lactose showed similar activities (21%, and 23%, respectively) suggesting that part of resveratrol was absorbed by the bacteria. Particles showed a regular spherical morphology with smooth surfaces, and size in the micrometer range (2−25 μm). The absence of bacteria in the SEM micrographs and the culturability activity suggested the preservation of the organisms within the micro and co-microencapsulated particles. The present work proposes the preparation of a functional food with probiotic and antioxidant properties.

Ceria-based mixed oxides have been widely studied in catalysis due to their unique surface and redox properties, with implications in numerous energy- and environmental-related applications. In this regard, the rational design of ceria-based composites by means of advanced synthetic routes has gained particular attention. In the present work, ceria−titania composites were synthesized by four different methods (precipitation, hydrothermal in one and two steps, Stöber) and their effect on the physicochemical characteristics and the CO oxidation performance was investigated. A thorough characterization study, including N2 adsorption-desorption, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), transmission electron microscopy (TEM) and H2 temperature-programmed reduction (H2-TPR) was performed. Ceria−titania samples prepared by the Stöber method, exhibited the optimum CO oxidation performance, followed by samples prepared by the hyd... [more]

Objective: Epilepsy is a neurological disorder arising from anomalies of the electrical activity in the brain, affecting ~65 million individuals worldwide. Prediction methods, typically based on machine learning methods, require a large amount of data for training, in order to correctly classify seizures with small false alarm rates. Methods: In this work, we present a new database containing EEG scalp signals of 14 epileptic patients acquired at the Unit of Neurology and Neurophysiology of the University of Siena, Italy. Furthermore, a patient-specific seizure prediction method, based on the detection of synchronization patterns in the EEG, is proposed and tested on the data of the database. The use of noninvasive EEG data aims to explore the possibility of developing a noninvasive monitoring/control device for the prediction of seizures. The prediction method employs synchronization measures computed over all channel pairs and a computationally inexpensive threshold-based classificat... [more]

This work assesses the behavior of organosolv lignin aggregates derived from Miscanthus x giganteus using different ethanol concentrations (10%, 25%, 50%, and 75% by volume). The percentage of lignin recovery was found to decrease from 75.8% to 71.4% and 25.1%, as the ethanol concentration was increased from 10% to 25% and 50%, respectively. Increasing the ethanol concentration further to 75% led to zero recovery. The purity of the precipitated lignin was consistently found to be ≥90%. Lignin derived from the dried supernatant obtained at 50% ethanol concentration resulted in high lignin purity (51.6%) in comparison with the other ethanol concentrations used. Fourier transform infrared spectroscopy analysis showed that the precipitated lignin and dried supernatant at 50% ethanol concentration possessed the highest peak intensity apportioned to wavenumber of lignin as compared to that of at 25% and 10% ethanol concentrations, and the results linked with the percentage of lignin purity.... [more]

CoO/Co3O4 nanoparticles (NPs) were synthesized by using a fresh egg white-assisted combustion method which acts as a new approach for green synthesis of this composite. This method was carried out by the direct heat of cobalt precursor with egg white at low temperature for very short period. In fact, this route is a novel, cheap and appropriate technique yielding nanoparticle-based materials. CoO/Co3O4 nanoparticles were characterized by examining the structure and identifying the elements and determining the morphology via XRD, FTIR, SEM, EDS and TEM techniques. The sample magnetic observations were measured through the use of a vibrating sample magnetometer (VSM). The results of XRD, EDS, SEM and TEM confirmed the positive synthesis of the cubic CoO/Co3O4 NPs with sponge crystals which proceed. For the as synthesized composite, 57.75 m2/g, 0.0148 cc/g and 10.31 nm were identified to be the SBET, Vp and ȓ, respectively. The cobalt oxide particles in their nature were polycrystalline,... [more]

The transformation of glucose into valuable biochemicals was carried out on different MCM-41-supported metallic and bimetallic (Co, Co-Fe, Co-Mn, Co-Mo) catalysts and under different reaction conditions (150 °C, 3 h; 200 °C, 0.5 h; 250 °C, 0.5 h). All catalysts were characterized using N2 physisorption, Temperature Programmed Reduction (TPR), Raman, X-ray Diffraction (XRD) and Temperature Programmed Desorption (TPD) techniques. According to the N2-physisorption results, a high surface area and mesoporous structure of the support were appropriate for metal dispersion, reactant diffusion and the formation of bioproducts. Reaction conditions, bimetals synergetic effects and the amount and strength of catalyst acid sites were the key factors affecting the catalytic activity and biochemical selectivity. Sever reaction conditions including high temperature and high catalyst acidity led to the formation mainly of solid humins. The NH3-TPD results demonstrated the alteration of acidity in diff... [more]

Raspberry extrudate residue has bioactive compounds in its matrix that are considered high-added value compounds. In the present study, different hydrothermal treatments were carried out using different operational systems, temperatures and times to solubilize raspberry extrudate in order to obtain these bioactive compounds (i.e., sugars and phenolic compounds). Hydrothermal treatment conditions were assessed in the range of 60 °C to 210 °C, with increments of 30 °C. The hydrothermal treatment at 210 °C for 5 min with direct steam and decompression was the most efficient process based on the solubilization of sugars and phenols, as well as on the antioxidant capacity of the products recovered in the liquid phase after treatment. Under these conditions, the concentration of soluble phenols was more than double the concentration in the raw raspberry extrudate, with more than 5000 mg phenols per kilogram of raspberry extrudate. The obtained values demonstrate the potential of applying thi... [more]

Microbial fuel cells (MFCs) are a promising technology for bioenergy generation and wastewater treatment. Various parameters affect the performance of dual-chamber MFCs, such as substrate flow rate and concentration. Performance can be assessed by power density ( PD ), current density ( CD ) production, or substrate removal efficiency ( SRE ). In this study, a mathematical model-based optimization was used to optimize the performance of an MFC using single- and multi-objective optimization (MOO) methods. Matlab’s fmincon and fminimax functions were used to solve the nonlinear constrained equations for the single- and multi-objective optimization, respectively. The fminimax method minimizes the worst-case of the two conflicting objective functions. The single-objective optimization revealed that the maximum PD ,   CD , and SRE were 2.04 W/m2, 11.08 A/m2, and 73.6%, respectively. The substrate concentration and flow rate significantly impact... [more]

The effects of UV-C irradiation (at doses of 8.16, 10.93, 16.17, and 33.29 mJ/cm2) on the physicochemical and microbiological properties of Agave tequilana Weber extracts at various pH values (4.5, 5.5, and 6.5) were evaluated. Thermal treatment (TT) was used as a control (85 °C for 30 s). Both processed (UV-C or TT) and unprocessed (UP) extracts were investigated. The UV-C dose and the pH significantly (p < 0.05) affected the inactivation of total coliforms (TC), total aerobic mesophiles (TAM), and yeasts and molds (YM). UV-C doses of 10.93 mJ/cm2 at pH 4.5 and 33.29 mJ/cm2 at any agave extract pH completely inactivated the native microbial load compared to TT. The total polyphenols (TP), antioxidant activity (AA), and sugar content did not change in the agave extracts at any dose, but the total flavonoid (TF) content decreased at doses > 16.17 mJ/cm2 at the evaluated pH values. Although the color of the agave extracts (L*, a*, and b*) was significantly affected, the total color diffe... [more]

Windcatchers are considered as promising passive ventilation and cooling strategy, but the ventilation performance of this system is still of concern in areas with low speed and unpredictable winds. The air short circuiting in windcatchers can reduce its ventilation performance and ability to introduce clean air and remove stale air. The current work aimed to evaluate the indoor environmental quality (IEQ) performance of a two-sided windcatcher fitted with an anti-short-circuit device (ASCD) for improving its performance in low wind speed conditions. Computational Fluid Dynamics (CFD) simulations were performed for different ASCD configurations. The CFD method was verified using grid-sensitivity analysis and validated by comparing the simulation results with wind tunnel data. The results indicated that the average difference between CFD results and previous experimentation was below 10%, therefore indicating good agreement. Building on the findings of the previous research, the study f... [more]

In order to solve the problems of flexible process route and workshop scheduling scheme changes frequently in the multi-variety small batch production mode, a multiprocess route scheduling optimization model with carbon emissions and cost as the multi-objective was established. At the same time, it is considered to optimize under the existing machine tool conditions in the workshop, then the theory of logistics intensity between equipment is introduced into the model. By designing efficient constraints to ensure reasonable processing logic, and then applying multilayer coding genetic algorithm to solve the case. The optimization results under single-target and multi-target conditions are contrasted and analyzed, so as to guide enterprises to choose a reasonable scheduling plan, improve the carbon efficiency of the production line, and save costs.