Metal Flow Rate Research Articles

Scaling down recombinant carbonic anhydrase isolation with immobilized metal ion chromatography (IMAC): Harnessing enzymatic carbon dioxide capture and mineralization

BackgroundHuman activities have led to increased atmospheric CO2 levels, raising concerns about climate change. Carbonic anhydrase (CA) enzymes show promise for transforming CO2 into valuable products like calcium carbonate (CaCO3) through mineralization. Purifying and immobilizing CA enzymes on nanofiber membranes enhances their catalytic activity, enabling efficient CO2 conversion and mineralization. MethodsRecombinant CA was purified using immobilized metal affinity chromatography (IMAC), optimizing pH, biomass concentration, flow rate, and loading volume for maximum efficiency. The CA enzyme was then immobilized onto a weak ion exchange nanofiber membrane functionalized with AEA-COOH to create the CA-modified membrane (AEA-COOH-CA), enhancing CO2 conversion and CaCO3 mineralization. Significant findingsOptimal purification conditions (pH 7, 1 % biomass, 0.1 mL/min flow rate, 1.0 mL loading volume) were determined using IMAC. The CA-modified membrane effectively converted CO2 and mineralized CaCO3, demonstrating the potential for environmental CO2 sequestration. The immobilized CA activities of the AEA-COOH-CA nanofiber membranes exhibited 473.42 WAU/g-membrane, corresponding to 7.10 WAU per membrane piece. The CaCO3 precipitation reached 83.90 mg, with a precipitation efficiency of 11.82 mg CaCO3/WAU. These findings underscore the promise of enzymatic carbon capture using CA-modified membranes, offering a sustainable solution for greenhouse gas mitigation.

Development and Application of a Constitutive Equation for 25CrMo4 Steel

The material constitutive equation of 25CrMo4 steel was established through an isothermal compression experiment. First, a thermal compression experiment was carried out with a Gleeble-3500 thermal simulator to study the thermoplastic deformation behaviour of 25CrMo4 steel at various temperatures (850, 950, 1050, and 1150 °C) and strain rates (0.01, 0.1, 1.0, and 10 s−1). The measured true stress–strain curve showed that when the temperature is constant, the flow stress increases with the strain rate, whereas when the strain rate is constant, the flow stress decreases with the temperature. Then, the constitutive model of peak stress of 25CrMo4 was established after analyzing the stress and strain statistics. The model parameters were optimized. The accuracy of the flow stress constitutive model was verified by comparing the flow stress prediction model with the experimental results. The hot forging process of the inner core wheel was numerically simulated based on DEFORM-3D v11 software, and the parameters of this process were formulated by analyzing the metal flow rate and equivalent stress and strain fields.

Removal of Copper and Zinc Metal Ions from Industrial Effluents in Continuous Mode using Modified Date Pits

Adsorbents based on agricultural biomass have been subjected to several investigations in recent years owing to their low cost and promising adsorption capabilities. This paper aimed to demonstrate the efficiency of utilizing date pits modified with hydrogen peroxide as agricultural biomass in extracting heavy metals from polluted water in a column continuous flow system. The resulting modified adsorbent (MDP) has a surface area of 278.18 m2/g. The derived adsorbent was investigated under changed operating parameters including the flow rate (4-12) ml/min, pH (4-10), initial metal ion concentration (30-60) mg/L, and temperature (20-50) °C to determine their effect on heavy metals adsorption efficiency. The response surface methodology (RSM) experimental design was utilized to study the primary and combined influence of four key parameters, including (A) initial metal ion concentration, (B) pH solution, (C) solution temperature, and (D) flow rates of the influent, on the metal removing efficiency (Re%). optimization in fact, an analysis of variance (ANOVA) revealed a high coefficient of regression, or R2 > 0.90. Furthermore, the removal efficiency was positively influenced by reducing the initial ion concentration, flow rate, and temperature. in addition, the pH shows maximum effectiveness at a neutral state. In general, Cu (II) adsorption shows a higher affinity to adsorb over the MDP surface compared to Zn (II). The MDP adsorbents exhibited a promising removal efficiency for metal ions and further investigations are needed.

Experimental investigation of MHD flows in a WCLL TBM mock-up

Experiments have been performed in the MEKKA laboratory of the Karlsruhe Institute of Technology to characterize the influence of a magnetic field on liquid metal flows in a scaled mock-up of the water-cooled lead-lithium test blanket module of ITER. The test section consists of eight breeder units that are fed and drained by long electrically coupled manifolds oriented along the poloidal direction. Pressure differences between several points of the mock-up have been recorded for various liquid metal flow rates and strengths of the imposed magnetic field. The main contributions to the total pressure drop in the test section have been identified as a function of characteristic flow parameters. For sufficiently strong magnetic fields, the experimental data shows that the non-dimensional pressure loss is practically independent of the flow rate, i.e. inertia forces become negligible. The experiments also confirm previous conclusions of magnetohydrodynamic experiments performed in a scaled-down mock-up of a helium-cooled lead-lithium blanket, namely that the largest pressure drop in the blanket module originates from the flow in the distributing and collecting manifolds. Moreover, the experimental study demonstrates that the current manifold design does not allow the flow to be uniformly distributed among all the breeder units.

Design and optimization of runner and gating systems, in high-pressure casting and sand casting, for an aluminum alloy valve cover

The weight and speed advantage of aluminum die-casting leads to its use in many parts in the automotive industry. Casting simulation programs are used, to avoid time-consuming and expensive production costs, and to design the production process. For casting production one of the most important factors is the runner design, which directly affects castability, material selection, and casting quality. With the correct design of runner systems, there will be no problem with the casting part. In this study, the final part and the runner design for the aluminum alloy valve cover were modeled in CAD, according to the empirical calculations. Furthermore, an appropriate casting method was selected for the valve cover not only according to the results of both high-pressure die-casting and sand-casting simulations but also economic calculations. The main technical parameters for selection were mold and part temperature distribution, liquid metal flow rates, cold shut possibilities, final air quantities, microporosity, and microporosity values. After the final decision, the casting part was produced with high pressure die casting by the implementation of the final runner design.

DESENVOLVIMENTO E ANÁLISE DE UM MÉTODO ALTERNATIVO PARA REMOÇÃO DE METAIS POTENCIALMENTE TÓXICOS DA ÁGUA EMPREGANDO MATERIAIS SORVENTES

The current work presents the use of a sorbent material to develop an alternative method for removing lead and barium from public water supplies. The sorbent material used was coconut fiber, which in addition to mitigating environmental pollution by reusing discarded waste, aids in the treatment of public water supplies by removing potentially toxic ions where conventional methods are not effective. In the alternative method used, we have a system of fixed bed reactors connected in series, with a volume of 0.250 L in each reactor. To characterize the adsorption process, we analyzed the variables pH, contact time, initial metal concentration, concentration of the sorbent material, and flow rate. Analysis of variance (ANOVA), multivariate analysis of variance (MANOVA), and the T-test were carried out. The parameters initial metal concentration and flow rate were shown to be non-significant for the confidence interval adopted in the conditions of the current work. The removal of Pb2+ and Ba2+ ions was greater than 60% in all the parameters studied, and in a single pass through the reactors, showing the viability of this procedure. Coconut fiber presented appropriate characteristics for the biosorption of lead and barium ions, constituting a sustainable and promising process to be used together with classical water treatment processes to remove potentially toxic metals.

Flow and heat transfer characteristics of microencapsulated phase change material slurry in bonded triangular tubes for thermal energy storage systems

Three nanoscale metal oxides composed of nano TiO2, nano Al2O3, and nano MgO were added to the phase change microcapsule slurry for optimising the heat transfer behaviour. The thermal and rheological properties of the resulting microencapsulated phase change materials (MPCMs) and microencapsulated phase change material slurries (MPCSs) were characterized to determine the effects of added metal oxides in optimising the performance of MPCSs. The impacts of factors like metal oxides, concentrations, and flow rates on the heat transfer behaviour of MPCSs were investigated by forced convective heat transfer experiment with various working conditions. Compared to 6 wt% MPCSs, the heat transfer coefficients (hx) of 6 wt% slurries containing 1 wt% TiO2, 1 wt% Al2O3, and 1 wt% MgO increased by 4.0 %, 2.5 %, and 7.13 %, respectively. Nano-MgO showed the most significant heat transfer enhancement effect on MPCSs. Moreover, the heat transfer performance gradually enhanced as a function of the concentration for nano MgO. Overall, the addition of metal oxides enhanced heat transfer by increasing the thermal conductivity of the slurry, as well as improved the micro-convection effect. The proposed MPCSs are promising for applications in solar photovoltaic/thermal (PV/T) systems, chip cooling, thermal management, buildings, and automotive cooling.

Dynamic elution of residual ion-exchangeable ammonium from weathered crust elution-deposited rare earth tailings

Ion-exchangeable ammonium (IEA), as one of the major existing forms of the residual ammonium in weathered crust elution-deposited rare earth tailings, has great potential to be released under natural conditions, which may lead to serious environmental pollution. Herein IEA distribution feature was determined, and five common ions (Al3+, Ca2+, Mg2+, Na+, and K+) were used as eluent to remove it from the tailings. Elution process and mechanism were studied in details. The results showed that IEA was mainly concentrated on illite which accounts for the largest proportion of the rare earth clay minerals (>65%). During the elution process, the metal ions initial concentration, flow rate, and particle size affected IEA removal efficiency while pH exhibited only a small effect, and the elution rate was controlled by internal diffusion. Among the selected eluents, the elution efficiency decreased in the order of K+>Mg2+>Al3+>Ca2+>Na+. The highest elution efficiency of IEA can reach 95.9% at an initial K+ concentration of 0.1 mol/L. Characterization results demonstrated that IEA could be effectively eluted by the metal ions through ion-exchange reaction. The results are valuable for choosing an efficient eluent and controlling the environmental pollution caused by the release of IEA.

Mechanism of oxide film removal and analysis of diffusion behavior of interfacial elements during magnetic pulse-assisted semi-solid brazing

The magnetic pulse-assisted semi-solid brazing (MPASSB) for Cu/Al tubes is proposed, in order to effectively remove oxide film to ensure the metallurgical bonding of Cu/Al brazing and joint performance. By designing a field shaper with a specific taper angle, the axial distribution of the electromagnetic force, tube deformation, and filler metal shear rheology are controlled to obtain the interface joining characteristics under different mechanical conditions. The relationship between the deformation behavior of the tube and filler metal with the interface element diffusion and metallurgical bonding is analyzed through the forming process simulation and interface microscopic characterization. In addition, the mechanical mechanism of oxide film removal is discussed as well. The results show that metallurgical bonding and element diffusion depend on the comprehensive effect of the interface compressive stress and the shear rheology of the filler metal. The larger the compressive stress, the better the oxide film removal. The stress at the bottom Cu/filler metal interface is the weakest, with an oxide layer thickness of 11.5 µm. The higher the shear rheological rate, the less the element diffusion depth. The filler metal flow rate at the bottom Cu/filler metal interface is the slowest, with a maximum depth of element diffusion of 13.5 µm. On the premise of ensuring the effective removal of the oxide film, the shear rheological rate (compressive stress) should not be too high.

Testing SALT Approximations with Numerical Radiation Transfer Code. I. Validity and Applicability

Absorption line spectroscopy offers one of the best opportunities to constrain the properties of galactic outflows and the environment of the circumgalactic medium. Extracting physical information from line profiles is difficult; however, for the physics governing the underlying radiation transfer is complicated and depends on many different parameters. Idealized analytical models are necessary to constrain the large parameter spaces efficiently, but are typically plagued by model degeneracy and systematic errors. Comparison tests with idealized numerical radiation transfer codes offer an excellent opportunity to confront both of these issues. In this paper, we present a detailed comparison between SALT, an analytical radiation transfer model for predicting UV spectra of galactic outflows, with the numerical radiation transfer software, RASCAS. Our analysis has led to upgrades to both models including an improved derivation of SALT and a customizable adaptive mesh refinement routine for RASCAS. We explore how well SALT, when paired with a Monte Carlo fitting procedure, can recover flow parameters from nonturbulent and turbulent flows. Overall we find that turbulence leads to biases in the recovery of kinematic parameters and the optical depth, but find that derived quantities (e.g., mass outflow rates, column density, etc.) are still well recovered. From the analysis, we estimate average uncertainties in our ability to measure metal flow rates spanning 0.65 (0.95) dex in M ⊙ yr−1 and uncertainties spanning 0.54 (0.94) dex in cm−2 for column densities at a resolution of 20 (100) km s−1 and signal-to-noise ratio = 10.

Identification of Aluminothermic Reaction and Molten Aluminum Level through Vision System

During the secondary production of aluminum, upon melting the scrap in a furnace, there is the possibility of developing an aluminothermic reaction, which produces oxides in the molten metal bath. Aluminum oxides must be identified and removed from the bath, as they modify the chemical composition and reduce the purity of the product. Furthermore, accurate measurement of molten aluminum level in a casting furnace is crucial to obtain an optimal liquid metal flow rate which influences the final product quality and process efficiency. This paper proposes methods for the identification of aluminothermic reactions and molten aluminum levels in aluminum furnaces. An RGB Camera was used to acquire video from the furnace interior, and computer vision algorithms were developed to identify the aluminothermic reaction and melt level. The algorithms were developed to process the image frames of video acquired from the furnace. Results showed that the proposed system allowed the online identification of the aluminothermic reaction and the molten aluminum level present inside the furnace at a computation time of 0.7 s and 0.4 s per frame, respectively. The advantages and limitations of the different algorithms are presented and discussed.

Metal hydride cylindrical tank for energy hydrogen storage: Experimental and computational modeling investigations

In this paper, experimental and numerical studies of hydrogen solid storage are investigated. An experimental test bench was implemented to investigate the hydride metal tank thermal behavior upon various cooling/heating modes. The metal hydride tank (La0.9Ce0.1Ni5), a 300 W proton exchange membrane fuel cell stack, and the auxiliary equipment to measure and regulate the physical parameters were used. Absorption and desorption processes were investigated under different operating conditions in order to address the performance of metal hydride. The metal has been thermally managed to minimize the charging time and to extend the operating time of the fuel cell. Different hydrogen charge pressures (4, 5, 6, 7, 9, 10 bar) were analyzed to define their effects on the metal hydride temperature, heat flux, flow rate and charging time. All these parameters were performed during charge and discharge processes for various inlet cooling temperature of 5 °C, 10 °C, 15 °C, 20 °C, 25 °C and 30 °C. The metal hydride could be charged quickly by hydrogen under high inlet pressure and using an efficient cooling mode with high heat transfer coefficient and cold temperature. The results show that more cooling temperature is low, much faster hydrogen is absorbed. Decreasing the cooling temperature increases the difference between the equilibrium pressure and the charging pressure and a higher absorbed hydrogen flow rate will obtain. The state of charge is increased by 1.6% by decreasing cooling temperature by 1 °C. However, the state of discharge increases with the heating temperature (2.5% per 1 °C).

Remediation of Pb (II), Cd (II), and Zn (II) from aqueous solutions using porous (styrene-divinylbenzene)/Cu-Ni bimetallic nanocomposite microspheres: continuous fixed-bed column study.

Bimetallic nanoparticles (BNPs) have been used as a new line of defence against heavy metal contamination among several types of nanoparticles (NPs) due to their enhanced, synergistic activity. In this study, we investigated the adsorption behaviour of porous (styrene-divinylbenzene)/CuNi bimetallic nanocomposite (P(St-DVB)/CuNi BNC) in a continuous flow fixed-bed column and its ability to remove Pb (II), Cd (II), and Zn (II) ions from aqueous solutions. We examined how the initial metal concentration, flow rate, and bed height affected the adsorption characteristics. Experimental results confirmed that the adsorption capacity increased with increase in influent metal concentration and bed height and decreased with increase in flow rate. The breakthrough and the column kinetic parameters were successfully predicted with three mathematical models: Thomas, Yoon-Nelson, and Adams-Bohart models. Both Thomas and Yoon-Nelson models showed good agreement with the experimental results for all the operating conditions. Successful desorption of heavy metals from the P(St-DVB)/CuNi BNC was performed using 0.5 M NaOH solution, and it showed good reusability of the adsorbent during four adsorption-desorption cycles. The results show that P(St-DVB)/CuNi BNC are effective and low-cost adsorbents, and they can be used in real-time large-scale industrial water treatment processes for the removal of heavy metals.

BATCH AND COLUMN STUDIES ON REMOVAL OF ERIOCHROME BLACK T DYE BY MICROALGAE BIOCHAR

<p>In this study, Chlorella vulgaris microalgae was cultivated from wastewater and converted into biochar through hydrothermal carbonization process. Acclimatization of microalgae resulted in a greater biomass yield of 4.1 g/L in 15 days in a Fog's medium to wastewater ratio of 20:80. Microalgae biomass was converted into biochar through hydrothermal carbonization process at temperature of 350 °C. The batch adsorption studies for the removal of Eriochrome Black T dye (EBT) from aqueous solution was performed by modifying various parameters. At an initial dye concentration of 100 ppm, a contact time of 60 min, a temperature of 30 °C, a biochar dosage of 0.3 g, and a pH of 7, the best dye removal efficiency was 82.31%. The investigation of the adsorption isotherm and kinetics revealed that the adsorption process followed pseudo-second order kinetics with the Langmuir isotherm model. In addition, the column adsorption investigations were carried out by varying the beads and bed height. Encapsulated beads outperformed control and hybrid beads in terms of removal efficiency. Column parameters such as initial metal ion concentration, bed height, and flow rate were optimised using the BDST model.</p>

Effects of groove clearance size on gap bridging capacity in PWLBW of Ti6Al4V alloy sheet assembled in butt joint configuration: Numerical simulation and experimental assessment

In laser tailor-welding of metal sheets, it is difficult to keep the assembly clearance fixed due to plate specification deviation, tooling error, and thermal deformation. In this paper, the influence of clearance size on gap bridging capacity and in turn the seam appearance quality was investigated for thin Ti6Al4V alloy plates, configured by an improved pulse wave laser beam welding (PWLBW) scheme. The welding experiment and the numerical simulation were performed at 1.2 mm-thick workpieces assembled in a butt joint with a reserved clearance. With the clearance size enlarged from 0.2 mm to 0.4 mm, the gap bridging type changes from bilateral to unilateral, which results in the failure of the keyhole to rebound during the pulse interval, and causes an obvious reduction in metal bridge area at the cross-section. As the clearance increases further, a through-cavity geometry is generated between the weld spots and finally preserved within the solidified weld bead, indicating a poor overlapping effect. The dynamics of the weld pool, including thermal cycle, Marangoni convection, and molten metal flow rate are exquisitely sensitive to the change in clearance size. The clearance size during assembly and welding processes should be controlled below 0.4 mm to attain seam integrity, continuity, and sound tensile property.

Multi-physics field coupling and microstructure numerical simulation of laser cladding for engine crankshaft based on CA-FE method and experimental study

During engine operation, the crankshaft journals are prone to wear, resulting in a decrease in surface matching accuracy and abnormal vibration and noise. Therefore, it is important to strengthen the surface and improve the wear resistance. Laser cladding, which involves multiple disciplines, such as automation control, optics, fluid mechanics, heat transfer, etc., is an effective method. In this paper, based on the finite element method, a numerical model of the laser cladding for the crankshaft journal was established. A disk laser was used to laser clad Fe45 powder on the ASTM1045 substrate. The multi-physics field coupling evolution mechanism of the laser cladding process was quantitatively revealed. The cladding temperature, liquid metal flow rate, and stress are positively correlated with the laser power. Combined with the cellular automata method, the microstructure evolution model during the solidification was established, and the morphology and size distribution of the grains in the cladding layer was obtained. In the middle area of the cladding layer, the grains are mostly columnar and equiaxed crystals. At the same time, the change of material physical parameters with temperature was taken into account in the model, which makes the numerical simulation results more accurate. The numerical simulation results were compared with the experimental results through the microscopic characterization experiment, and the accuracy of the numerical model was verified. Finally, through a friction-wear test, the wear resistance between the cladding layer and the substrate is compared. The average wear amount of the substrate is 1.86mm3 and the average wear amount of the cladding layer is 0.64mm3. The experiment shows that the wear resistance of the cladding layer is higher than that of the substrate, and the wear rate is reduced by 65.59%.

Numerical and experimental study on oscillation mechanism of molten pool during pulsed microplasma arc welding ultrathin sheets

Molten pool oscillation behaviors during pulsed microplasma arc welding ultrathin stainless steel sheets were studied based on the numerical simulation, experimentally visual detection, and theoretical calculation. Without altering the average heat input, the effects of different pulse parameters of welding current on weld pool oscillation frequency and oscillation amplitude were discussed. It showed that the changes either in the weld pool temperature and liquid metal flow rate or in weld pool size cannot keep up with the rapid variations of welding current from base current to peak current or from peak current to base current. The mainly periodic changes of molten pool size and liquid metal flow rate are caused by pulsed current. However, on these main periodic changes, small amplitude fluctuations are superimposed due to weld pool oscillations. The oscillation frequency decreases and the oscillation amplitude increases slightly with the growth of molten pool. Oscillation frequency increased with an elevating in pulsed current frequency, and it rose firstly and then fell when duty cycle of pulsed current increased. Moreover, concerning the fluctuations in weld pool size, the oscillation amplitude reduced with the enhancement in pulsed current frequency though there were no obvious variations in it with the variations in duty cycle of welding current.

Modern development of elements of theory, technology and mini-mills of radial-shear rolling

Formulas for calculating the trajectory deformation coefficients during radial-shear rolling are presented in an analytical form, which make it possible to estimate the gradient of the deformation-kinematic state of the metal under conditions of helicoidal flow. The layer-by-layer nature of the change in the metal flow rate, coefficients, intensity, and deformation schemes has been established. An expression for evaluating the rotational deformation is obtained. The basic schemes for setting up symmetrical three-roll calibers used in the RSR minimills are presented. The technical characteristics of the modern line of RSR minimills designed by MISIS are presented. The basic arrangement of mills 30-70 and 90-220 is described, which significantly expands the dimensional range of rolling diameters on RSR minimills. Effective technological solutions based on RSR, implemented in practice, are discussed. In particular, in the field of creating low-cost technologies for recycling and secondary use of lengthy machine-building parts taken out of service. On the example of minimill 90-220 of a special design, the possibility of using RSR for preliminary deformation of continuously cast billets under the conditions of an operating industrial PRP-160 with a three-roll rolling mill is shown.

The effect of beam oscillation on laser welding of AA2219-T87 under subatmospheric pressure

Aluminum alloy AA2219 is widely used in the aerospace industry due to its high specific strength, and corrosion resistance, especially for the production of propellant tanks of space rockets. With the rapid development of laser sources, the welding of metal materials changes gradually from arc welding to laser welding, but pore defect drags the application of laser welding of aluminum alloy. To solve this bottleneck problem, this paper investigates the effect of laser beam oscillation on welding of AA2219 under subatmospheric pressure (LOWSP). The experimental results showed that LOWSP has significantly improved the surface morphology, penetration depth, microstructure,and mechanical properties of the weld seam. The EBSD testing analysis shows that the low-angle grain boundaries (LAGBs) take up the largest proportion in the microstructure with the increased proportion of equiaxed grains, and the grain size is further refined in LOWSP. When welded at the optimal laser beam oscillation frequency of 80 Hz under the pressure of 102 Pa, the pore was almost inhibited and the tensile strength of the weld seam reached 388.62 MPa, up to 83.16% of the base metal (the current level of the industry is generally between 300 ∼ 360 MPa). It is believed that the reduced boiling point of the aluminum alloy under subatmospheric pressure accelerated the molten metal flow rate, the stirring effect of laser beam oscillation on weld microstructure within molten pool significantly eliminate porosity, therefore the LOWSP process generated the refined grain size and the improved mechanical properties of the weld seam.

Numerical Analysis on Erosion and Optimization of a Blast Furnace Main Trough.

The main trough of a blast furnace (BF) is a main passage for hot metal and molten slag transportation from the taphole to the torpedo and the slag handling. Its appropriate working status and controlled erosion ensure a safe, stable, high-efficiency and low-cost continuous production of hot metal. In this work, the tapping process of a main trough of a BF in the east of China was numerically studied with the help of a CFD library written in C++, called OpenFOAM, based on the use of the Finite Volume Method (FVM). The results show that turbulence intensity downstream of the hot metal impact position becomes weaker and the turbulence area becomes larger in the main trough. During the tapping, thermal stress of wall refractory reaches the maximum value of Pa at the 4 m position in the main trough. Furthermore, baffles in the main trough placed between 5.8 m and 6.2 m were found to control and reduce the impact of the turbulence on the refractory life. The metal flowrate upstream of the baffles can be decreased by 6%, and the flow velocity on the upper sidewall and bottom wall decrease by 9% and 7%, respectively, compared with the base model. By using baffles, the minimum fatigue life of the refractory in the main trough increases by 15 tappings compared with the base model, so the period between the maintenance stops can be prolonged by about 2 days.