The paper presents the concept of new swirl inserts. An empty two-phase swirl flow atomizer, and three atomizers with inserts were designed, manufactured and tested. The tested atomizers did not differ in terms of their geometric dimensions, with the only variable being the type swirl chamber filling. Flow resistance and spray angle values were analysed for all the evaluated structures. It was shown that the presence of a swirl insert does not significantly increase flow resistance, but instead results in larger spray angles. Taking into account the values of flow resistance and spray angles, the best design solution turned out to be the set of inserts No. 2.

In the paper, the mixing power and distributions of velocity and velocity pulsations in a baffled stirred tank with a flat blade turbine impeller placed at different distances from the bottom were determined. It was found that the mixing power reaches minimum values when the relative clearance of the impeller is C/D = 0.6÷0.7. The investigations of velocity distributions using the PIV method showed the axial flow of the liquid through the impeller. This results in deviations from the typical radial-circumferential flow and changes in mixing power vs. impeller clearance versus a Rushton impeller. With a clearance corresponding to the minimum power, the flow is axial-circumferential with one circulation loop. For a flat blade turbine impeller, good mixing conditions are obtained for a clearance of 0.8 < C/D < 0.9.

When designing injectable scaffolds for biomedical applications, it is crucial to determine the conditions for the formation of unlimited structures, in particular the kinetics at constant temperature. Despite many studies, these conditions have not been characterized so far after injection, which is such an important application aspect. The aim of the research is to discuss the impact of the injection application on the polymer structure and to propose new criteria for assessing the potential of thermosensitive biopolymer sols, considering the flow under high shear rates during the administration.
Based on the analysis of the obtained results of rheological tests, it was shown that the flow through the needles causes a significant change in the elastic properties that define the polymer structure, with almost unchanged viscous properties. As a consequence, the parameters characterizing the polymer coil change, which, combined with the quantitatively proven fragmentation, indicates that injection application may affect the size of the coils that will not reach the critical size of the aggregating nucleus.
Finally, extended research procedures for the conscious design of injectable scaffolds are proposed as well as key rheological parameters to ensure thermoinduced aggregation preceded by shear during injection are provided.

This study aims at the immobilization and characterization of thermoalkalophilic lipases produced recombinantly from Bacillus thermocatenulatus BTL2 and Bacillus pumilus MBB03. For this purpose, immobilization of the produced enzymes in calcium-alginate@gelatin (Ca–Alg@gelatin) hydrogel beads, immobilization optimization and characterization measurements of the immobilized-enzyme hydrogels were conducted. Optimum temperature and pH values were determined for B. thermocatenulatus and B. pumilus MBB03 immobilized-enzyme hydrogels (60–70 °C, 55 °C and pH 9.5, pH 8.5). Thermal stability was determined between 65 °C and 60 °C of B. thermocatenulatus and B. pumilus MBB03 immobilized enzymes, respectively. The pH stability was determined between pH 7.0–11.0 at +4°C and pH 8.0–10.0 at +4 °C, respectively.
In conclusion, the entrapment technique provided controlled production of small diameter hydrogel beads (~ 0:19 and ~ 0:29) with negligible loss of enzyme. These beads retained high lipase activity at high pH and temperature. The activity of Ca–Alg@gelatin-immobilized lipase remained relatively stable for up to three cycles and then markedly decreased. With this enzyme immobilization, it may have a potential for use in esterification and transesterification reactions carried out in organic solvent environments. We can conclude that it is one of the most promising techniques for highly efficient and economically competent biotechnological processes in the field of biotransformation, diagnostics, pharmaceutical, food and detergent industries.

Three activated chars obtained from end-of-life tyre pyrolysis differing in activation time (AC110 – 110 min, AC130 – 130 min, and AC150 – 150 min) were successfully used as adsorbents for the removal of model dye – Rhodamine B (RhB) from aqueous solutions. The effects of solution pH, adsorption kinetics, and equilibrium adsorption were investigated. The results showed that the adsorption was strongly pH-dependent; the highest percentage of RhB dye adsorbed was obtained at pH 2.0 and the removal efficiency decreased with an increase in solution pH. Adsorption kinetics was analyzed using pseudo-first-order, pseudo-second-order, Weber-Morris, and Boyd kinetic models. It was found that the pseudo-second-order kinetic equation was the most appropriate for describing the adsorption kinetics and that the RhB adsorption process was controlled by a film diffusion mechanism. Adsorption equilibrium data were fitted to the Langmuir, Freundlich, Temkin, and Elovich isotherm models. The equilibrium data were best represented by the Langmuir model with the monolayer adsorption capacities of 69.96, 94.34, and 133.3 μmol/g for AC110, AC130, and AC150, respectively. It was concluded that the adsorption of RhB was closely correlated with the specific surface area (and activation time) of the activated chars.

Mercury is a highly toxic metal which naturally occurs in the Earth’s crust and has adverse effects on both humans and the environment. The use of fossil fuels for electricity generation and specific industries sources of mercury emissions. These emissions depend on the mercury content in fuels of different types, the process gas temperature and composition, the implementation of air pollutant control devices (APCDs), etc. The APCDs partially capture and/or oxidize mercury in flue gas as a side benefit. In some cases, the emissions are reduced by mercury-dedicated or mixed methods. Mercury transformation in process gases is generally based on a chain of homogeneous and/or heterogeneous reactions. The theory of gaseous mercury/solid phase reactions and its mechanisms is widely studied in the literature. In this review, we focused on the theoretical and practical studies of these mechanisms, including mercury oxidization and capture from specified laboratory simulated or process gases and industries. We summarized research on various reactions – mostly of a chemical type – between different forms of mercury derived from process gases, and solids, including particles of different kinds (fly ash, adsorbents or catalysts). We additionally reviewed the literature on the interactions between mercury and sulfur compounds in the simulated and process gases.

The mathematical approach to SOFC modelling helps to reduce dependence on the experimental approach. In the current study, six different diffusion mass transfer models were compared to more accurately predict the process behavior of fuel and product diffusion for SOFC anode. The prediction accuracy of the models was extensively studied over a range of parameters. New models were included as compared to previous studies. The Knudsen diffusion phenomenon was considered in all the models. The stoichiometric flux ratio approach was used. All the models were validated against experimental data for a binary (CO-CO2) and a ternary fuel system (H2-15 H2O-Ar). For ternary system, the pressure gradient is important for pore radius below 0.6 μm and current density above 0.5 A/cm2. For binary system, the pressure gradient may be ignored. The analysis indicates that the MBFM is identified to be the best performing and versatile model under critical SOFC operating conditions such as fuel composition and cell temperature. The diffusive slip phenomenon included in MBFM is useful in SOFC operating conditions when fuel contains heavy molecules. The DGMFM is a good approximation of DGM for the binary system.

This study presents the results of tests on the mixing power and distribution of three velocity components in the mixing tank for an FBT impeller during tank emptying with an operating impeller. A laser PIV system was used to determine speed distributions. It was found that for the relative liquid height in the tank H* = H/H0 ≈ 0.65 and H* ≈ 0.45, the liquid circulation in the impeller zone changed from radial to axial and vice versa. These changes were accompanied by changes in the mixing power which even reached 40%. In the theoretical part, a method of calculating the mixing power using the classical model of the central vortex and distribution of the tangential speed in the impeller zone was proposed. Although the method turned out to be inaccurate, it was useful for determining the relative power.

Unsteady motion of the impeller is one of the several methods to improve mixing in unbaffled vessel. It is very important in pharmaceutical industry, crystallization processes or some chemical reaction with catalyst where baffles are not recommended. The literature data shows that unsteady mixing cause generation of axial flow for radial impellers (Rushton turbine). The purpose of this study was to investigate axial force for axial impellers like A315, HE-3 and SC-3. Moreover, the momentum number, flow number and pumping efficiency were analysed. Results shows that axial force for unsteady mixing is higher in comparison to steady-state mixing. Also, the comparison of axial force between impellers shows that blades influence momentum number and flow number. Impellers with larger blade surface generate stronger axial force. The obtained results reveal that unsteady mixing with axial impellers could be apply for solid-liquid mixing as suitable alternative to steady-state mixing.

The paper presents the effects of sodium chloride on the rheological properties of aqueous solutions of cocamidopropyl betaine (CAPB) and sodium dodecylbenzene sulfonate (SDBS) mixtures. Studies were carried out in the CAPB/SDBS molar ratio range of 0.95 to 3.5, at sodium chloride concentrations varying from 0.03 M to 0.75 M. Continuous and oscillatory flow measurements showed that the impact of sodium chloride concentration on shear viscosity and relaxation time was closely linked to the CAPB/SDBS molar ratio. The maximum shear viscosity and the longest Maxwell relaxation time were obtained at the CAPB/SDBS molar ratio of 2. Based on CryoTEM images, it was determined that the shear viscosity and relaxation time peaks identified at a certain concentration of sodium chloride could be attributed to the transition of the entangled wormlike micellar network into branched wormlike micelles. Changes in the micellar microstructure accompanying modifications of the CAPB/SDBS molar ratio and sodium chloride concentration were accounted for on the basis of the packing parameter.

The work presents a two-step method of iron red synthesis based on waste iron(II) sulfate. The synthesis was carried out using purified waste iron sulfate from titanium dioxide production. The study investigated the influence of factors such as temperature, pressure, concentration of solutions and synthesis time on the physicochemical properties of pigments. Obtained pigments were tested by instrumental analytical methods, e.g. X-ray Diffraction or BET surface area analysis. The pigments were analyzed for color, praticles size as well as for oil number. The results of the research showed a change in the physicochemical properties of the obtained pigments depending on the conditions of synthesis. It was shown that increasing the synthesis time in most cases increased the degree of crystallization of hematite in the pigments. High specific surface area, low agglomeration of pigments or low oil absorption are directly related to the crystallinity of the pigments obtained. Laboratory pigments have been found to be different from commercial pigments. The difference in properties speaks in favor of synthesized materials.

Carbonic anhydrase is an important enzyme that can play a significant role in the processes of lowering carbon dioxide concentration in the atmosphere. The aim of the work was to investigate the extracellular carbonic anhydrase (CA) production by the bacteria Pseudomonas fragi. In the research, we focused on the evaluation of the phase of bacterial growth correlated with carbonic anhydrase production and on the evaluation of induction of CA production by calcium carbonate concentration in the nutrient medium. Presented data indicated that calcium carbonate can serve as the only carbon source for Pseudomonas fragi, inducing carbonic anhydrase secretion to culture broth. The enzyme was produced mainly in the adaptation growth phase reaching the maximal activity at the end of this phase or at the beginning of the growth phase. The maximal enzyme activity detected in all batches was at a similar level. The enzyme activity was constant but lower in the exponential phase growth. Therefore, the enzyme production is not growth-dependent, but it is correlated with bacteria adaptation to cultivation conditions.

Here One important aspect of the process of anaerobic stabilisation of sewage sludge in medium and large sewage treatment plants, in addition to sludge mineralisation, is the acquisition of a valuable source of energy, which is biogas. There are well-known methods of intensifying the process of methane fermentation by subjecting sludge to disintegration using physical factors, i.e. ultrasonic field. Acetate production is the ratelimiting step in the acetate consumption pathway and affects the efficiency of the anaerobic stabilisation process. The product of the first stage of the process is also the substrate for the next stage. Therefore, it is advisable to subject sewage sludge to disintegration, which increases its susceptibility to biodegradation. Sludge modification with the above-mentioned method causes a significant increase in the concentration of organic substances in the supernatant liquid. The reflection of the physical and chemical transformations of sludge in the disintegration processes is the change in their structure expressed by the increase in the degree of particle dispersion. The disintegration of sludge using sonolysis is an effective process solution, both in terms of technology and energy, in terms of obtaining biogas, which is a valuable source of energy.

The two aims of this study were to obtain stable thyme-oil loaded nanoemulsions using the statistical design of experiment method (DOE) and to confirm their antimicrobial and disinfecting properties. Thyme oil was used as the oil phase, ECO Tween ® 80 acted as an emulsifier, and the rest of the formulation was deionized water. Ultrasonication was chosen as the method of obtaining the nanoemulsions. It was checked whether the input parameters (oil concentration, emulsifier concentration, amplitude, and sonication time) had a significant impact on the output parameters (nanoemulsion particle size, polydispersity index, viscosity, and stability over time). For the formulations selected on the basis of the statistical data analysis, the values of minimum inhibitory concentrations (MIC) and minimum biocidal concentrations (MBC/MFC) were determined in relation to 10 bacterial strains and 10 strains fungi (filamentous fungi, yeast-like fungi). The results obtained from the statistical analysis showed that the optimal concentration of the thyme oil in nanoemulsion should amount up to 2%. Biological studies proved that the obtained formulation had stronger antibacterial and antifungal activity compared to pure oil. Moreover, it was shown that the nanoemulsion caused the required for disinfectants reduction of > 5 log of bacterial strains ( S. aureus, P. aeruginosa) and > 4 log of fungal strains ( C. albicans) after 30 minutes.

Life Cycle Assessment (LCA) is an important tool of Circular Economy (CE), which performs the analysis in a closed loop (“cradle-to-cradle”) of any product, process or technology. LCA assesses the environmental threats (climate change, ozone layer depletion, eutrophication, biodiversity loss, etc.), searches for solutions to minimize environmental burdens and together with CE contributes to reducing greenhouse gas emission, counteracts global climate crisis. The CE is a strategy for creating value for the economy, society and business while minimizing resource use and environmental impacts through reducing, re-using and recycling. In contrast, life cycle assessment is a robust and science-based tool to measure the environmental impacts of products, services and business models. Combining both the robustness of the LCA methodology and the principles of circular economy one will get a holistic approach for innovation. After a presentation of the LCA framework and methods used, 27 examples of case studies of comparative LCA analysis for replacement materials to reduce environmental load and their challenges as assessment methods for CE strategies are presented. It was concluded that there is a need for improvement of existing solutions, developing the intersection between the CE and LCA. Suggestions for developing a sustainable future were also made.

This work presents results of investigations on biotrickling filtration of air polluted with cyclohexane co-treated in binary, ternary and quaternary volatile organic compounds (VOCs) mixtures, including vapors of hexane, toluene and ethanol. The removal of cyclohexane from a gas mixture depends on the physicochemical properties of the co-treated VOCs and the lower the hydrophobicity of the VOC, the higher the removal efficiency of cyclohexane. In this work, the performance of biotrickling filters treating VOCs mixtures is discussed based on surface tension of trickling liquid for the first time. A mixed natural – synthetic packing for biotrickling filters was utilized, showing promising performance and limited maintenance requirements. Maximum elimination capacity of about 95 g/(m ³·h) of cyclohexane was reached for the total VOCs inlet loading of about 450 g/(m ³·h). This work presents also a novel approach of combining biological air treatment with management of a spent trickling liquid in the perspective of circular economy assumptions. The waste liquid phase was applied to the plant cultivation, showing a potential for e.g. enhanced production of energetic biomass or polluted soil phytoremediation.

Chemical and process engineering offers scientific tools for solving problems in the biomedical field, including drug delivery systems. This paper presents examples of analyzing the dynamics of dispersed systems (aerosols) in medical inhalers to establish a better relationship between the test evaluation results of these devices and the actual delivery of drugs to the lungs. This relationship is referred to as in vitro-in vivo correlation (IVIVC). It has been shown that in dry powder inhalers (DPls), the aerosolization process and drug release times are determined by the inhalation profile produced by the patient. It has also been shown that inspiratory flow affects the size distribution of aerosols generated in other inhalation devices (vibrating mesh nebulizers, VMNs), which is due to the evaporation of droplets after the aerosol is mixed witha dditional air taken in by the patient. The effects demonstrated in this work are overlooked in standard inhaler testing methods, leading to inaccurate information about the health benefits of aerosol therapy, thus limiting the development of improved drug delivery systems.

The paper discusses the application possibilities of ceramic foam in a thermal combustion process of a lean methane-air mixture. The experiments were done in a ceramic foam bed. The foam (Vukopor ^® A) was made mainly of Al ₂O ₃. The foam samples were packed in a tubular reactor symmetrically placed in a laboratory furnace. It was assumed that the tested foam should have a surface close to the monolith surface area which was tested in a previous work (Pawlaczyk and Gosiewski, 2015). Pore density of the tested foam was 10 PPI. The tested air mixture contained 0.51 - 0.76 vol. % of methane. The results show that thermal methane oxidation in foam is possible in the acceptable range of temperatures. The combustion process in foam is characterized by similar ignition temperature to tests carried out in monolith, a more intense course, and better methane conversion at lower temperatures.

In the presented work, the conditions of the high-temperature and mechanochemical method for the synthesis of compound Sm ₅VO ₁₀ and their influence on its physicochemical properties were studied. The following methods were used for the study: X-ray powder diffraction (XRD), differential thermal analysis (DTA), infrared spectroscopy (FTIR), ultraviolet and visible light spectroscopy (UV–VIS–DRS), scanning electron microscopy (SEM-EDX), and laser beam diffraction spectrometry (LDS). Based on the results, it was determined that the compound Sm ₅VO ₁₀ is thermally stable in air atmospheres up to 1475 °C, crystallises in a monoclinic system, and its structure is made up of oxygen VO ₄ and SmO ₈ polyhedra. The estimated energy gap value for nanometric, mechanochemically obtained Sm ₅VO ₁₀ was about 3.20 eV, and for the microcrystalline, obtained with the high-temperature method, was about 2.75 eV. The established physicochemical characterisation of Sm ₅VO ₁₀ initially showed that the compound could find potential applications, e.g. as a photocatalyst for water purification or as a component of new optoelectronic materials.

Simplified optimization method using the MATLAB function fminbnd was adopted to determine the optimal feed temperature (OFT) for an isothermal packed-bed reactor (PBR) performing hydrogen peroxide decomposition (HPD) by immobilized Terminox Ultra catalase (TUC). The feed temperature was determined to maximize (minimize) the average reactant conversion (reactant concentration) over a fixed period time at the reactor outlet. The optimization was based on material balance and rate equation for enzyme action and decay and considered the effect of mass-transfer limitations on the system behavior. In order to highlight the relevance and applicability of the work reported here, the case of optimality under isothermal operating conditions is considered and the practical example is worked out. Optimisation method under consideration shows that inappropriate selection of the feed temperature may lead to a decrease in the bioreactor productivity.

Cosmetic emulsion bases containing extracts from natural plants were produced. The emulsifier was an aqueous solution of self-emulsifying base made from apricot kernel oil and soy lecithin, while the oil phase was based on coconut, almond or grape seed oils. In addition, mixtures enriched with vegetable glycerine were produced. It was found that for the emulsions with almond oil as the concentration of the oil phase increased, the value of the average Sauter diameter increased. In comparison, results for emulsions with coconut oil and emulsions with grapeseed oil did not give such a clear relationship. It was also shown that for stable emulsions, the self-emulsifying base of apricot kernel oil performed much better than soy lecithin. The addition of vegetable glycerine to the mixture resulted in a reduction of the average droplet diameter. Produced emulsions were also visually observed for 60 days to assess their stability and possible aging processes. In order to exclude the formation of microorganisms, periodic density control and microscopic examinations were carried out. The presence of microorganisms 30 in the analysed emulsion was evaluated using microscopic and culture techniques. No tarnish waso bserved on the surface of the samples, indicating the formation of mould, which can lead to poisoning and the development of allergies, respiratory diseases, liver diseases, ulcers, or bleeding in the intestines.

In recent years, European countries have experienced a noteworthy surge in the interest surrounding renewable energy sources, particularly the integration of photovoltaic (PV) panels with various types of heat pumps. This study aims to evaluate the energy performance of a grid19 connected hybrid installation, combining a PV array with an air-source heat pump (AHP), for domestic hot water preparation in a residential building located in Cracow, Poland. The primary focus of this evaluation is to assess the extent to which self-consumption (SC) of energy can be increased. The study utilizes Transient System Simulation Tool 18 software to construct and simulate various system models under different scenarios. These scenarios include building electricity consumption profiles, PV power systems, and the specified management of AHP. Analyses were conducted over a period of 1 year to assess the operational performance of the systems. In the considered installations, the differences in SC values between PV installation ranged from 9 to 25%. Notably, the highest SC values were observed during the winter months. AHP with operation control allows to obtain in some months of the year up to 35% higher value the SC parameter compared to systems without AHP. The highest annual 29 SC value recorded reached 83.9%. These findings highlight the crucial role of selecting an appropriate PV system size to maximize the SC parameter.

The work motivation was to investigate in vitro system simulating drug release from Drug Eluting Stent (DES). The experiments were conducted in a custom designed unit simulating drug release from polymer covering DES in a simplified way. The active substance diffuses from a thin, internal annular layer of hydrogel (imitating “stent”) to the outer cylindrical layer of hydrogel (“artery wall”) and is at once drifted away by coaxially flowing solution (“blood”). The conducted research proved functionality of the experimental unit. The rate of mass transfer depends considerably on the mass driving force and on the affinity of substance-hydrogel. The volumetric flow rate and liquid viscosity did not affect the process significantly. The effective diffusion coefficient was calculated as a process parameter and then used in the other variants. Diffusion in hydrogel is the mechanism limiting the mass transfer in the examined system. For the first attempt, the diffusive model used in literature was employed. The provided calculations are consistent with experimental data and therefore show that despite its simplifications the model allows to estimate the amount of released substance.
In conclusion, the relative substance mass, changing over time, was estimated in the respective parts of the unit. The prospect of determining the relative mass of the substance appearing in the subsequent parts of the system over time provides the opportunity to adjust the respective process parameters, which will facilitate control over the rate of mass release.

The influence of a fixed adsorption bed height on the adsorption process was studied using acetone, ethyl acetate, toluene, and n-butyl acetate as a gaseous adsorbate mixture. All experiments were conducted under the same gas flow and temperature conditions. Concentrations of adsorbates were monitored using gas chromatography with a flame ionization detector. Activated carbon WG-12 (Grand Activated Sp. z o.o) was selected as the adsorbent, and the following heights of the fixed adsorption bed were used: 0.8, 1.6, 3.2, and 4.8 cm. The results of the study allowed to deduce that as the height of the fixed adsorption bed increased, the degree of displacement of adsorbate molecules from the bed strengthened. In addition, it was found that both the bed breakthrough time increased linearly with a height rise of the fixed adsorption bed. The process carried out on a fixed adsorption bed with a height of 0.8 cm was characterized by an undeveloped mass transfer zone, as well as the complete displacement of the most volatile components (acetone and ethyl acetate). The utilization rate of the fixed adsorption bed also increased as the height of the adsorption bed went up. However, at a certain bed height, the bed breakthrough curves were formed and the adsorption capacity did not change significantly, solely the bed breakthrough time increased.