Central Axis Research Articles

Investigation of the three-dimensional structure of low-swirl methane-hydrogen flames with multiple UV cameras-based OH* chemiluminescence tomography

Blending hydrogen with natural gas is useful for reducing CO2 emissions, but this alters the flame structure, creating challenges for flame stability. Numerous researches on methane-hydrogen flame structure have been carried out based on two-dimensional combustion diagnostic techniques such as flame chemiluminescence and planar laser-induced fluorescence. In this paper, a low-cost OH* chemiluminescence imaging system consisting of 8 ultraviolet (UV) cameras is proposed to reconstruct the three-dimensional (3D) structure of methane-hydrogen flames, and validated through use of the correlation coefficient. Further experimental investigations of the low-swirl methane-hydrogen flames are performed by this computed tomography of chemiluminescence (CTC) system. The flame properties are determined to evaluate the effects of various fractions of blended hydrogen on the flame structure, including the flame center of mass, flame surface density and fractal dimension. Results showed that the flame initially has bowl-shape structure. The flame height gradually decreases and the flame cross-sectional area increases as the blended hydrogen fraction increases. Meanwhile, the bottom of the flame moves toward the nozzle outlet. Nevertheless, when the blended hydrogen fraction reaches 50%, the flame transforms into a cup-shaped flame and shows a double-layer flame structure. When the flame is bowl-shaped, the flame center of mass moves away from the nozzle center axis with increasing blended hydrogen fraction, but the fractal dimension and flame surface density are not sensitive to the blended hydrogen fraction. In contrast, when the flame is cup-shaped, the flame center of mass moves towards the nozzle center axis, and the flame surface density and fractal dimension increase significantly, indicating the increase of flame wrinkling. These results reveal that blending hydrogen leads to two distinct flame structures and characteristics in low-swirl flame, also demonstrate that the proposed 3D low-cost CTC system based on multiple UV cameras is well-suited for combustion diagnostics.

Unveiling the Anatomical and Functional Attributes of Stipular Colleters in Palicourea tetraphylla Cham. & Schltdl. and Palicourea rudgeoides (Müll. Arg.) Standl. (Rubiaceae).

The characterization of colleters in Rubiaceae is crucial for understanding their role in plant function. Analyzing colleters in Palicourea tetraphylla and Palicourea rudgeoides aims to deepen the understanding of these structures morphoanatomical and functional characteristics. The study reveals colleters with palisade epidermis and a parenchymatic central axis, classified as standard type, featuring vascularization and crystals. Colleter secretion, abundant in acidic mucopolysaccharides, proteins, and phenolic compounds, protects against desiccation. The ontogenesis, development, and senescence of the colleters are quite rapid and fulfill their role well in biotic and abiotic protection because these structures are present at different stages of development in the same stipule. Pronounced protrusions on the colleters surface, coupled with the accumulation of secretion in the intercellular and subcuticular spaces, suggest that the secretory process occurs through the wall, driven by pressure resulting from the accumulation of secretion. The microorganisms in the colleters' secretion, especially in microbiota-rich environments such as the Atlantic Forest, provide valuable information about plant-microorganism interactions, such as resistance to other pathogens and organisms and ecological balance. This enhanced understanding of colleters contributes to the role of these structures in the plant and enriches knowledge about biological interactions within specific ecosystems and the family taxonomy.

Application of stoichiometric CT number calibration method for dose calculation of tissue heterogeneous volumes in boron neutron capture therapy.

Monte Carlo simulation code is commonly used for the dose calculation of boron neutron capture therapy. In the past, dose calculation was performed assuming a homogeneous mass density and elemental composition inside the tissue, regardless of the patient's age or sex. Studies have shown that the mass density varies with patient to patient, particularly for those that have undergone surgery or radiotherapy. A method to convert computed tomography numbers into mass density and elemental weights of tissues has been developed and applied in the dose calculation process using Monte Carlo codes. A recent study has shown the variation in the computed tomography number between different scanners for low- and high-density materials. The aim of this study is to investigate the effect of the elemental composition inside each calculation voxel on the dose calculation and the application of the stoichiometric CT number calibration method for boron neutron capture therapy planning. Monte Carlo simulation package Particle and Heavy Ion Transport code System was used for the dose calculation. Firstly, a homogeneous cubic phantom with the material set to ICRU soft tissue (four component), muscle, fat, and brain was modelled and the NeuCure BNCT system accelerator-based neutron source was used. The central axis depth dose distribution was simulated and compared between the four materials. Secondly, a treatment plan of the brain and the head and neck region was simulated using a dummy patient dataset. Three models were generated; (1) a model where only the fundamental materials were considered (simple model), a model where each voxel was assigned a mass density and elemental weight using (2) the Nakao20 model, and (3) the Schneider00 model. The irradiation conditions were kept the same between the different models (irradiation time and irradiation field size) and the near maximum (D1%) and mean dose to the organs at risk were calculated and compared. A maximum percentage difference of approximately 5% was observed between the different materials for the homogeneous phantom. With the dummy patient plan, a large dose difference in the bone (greater than 12%) and region near the low-density material (mucosal membrane, 7%-11%) was found between the different models. A stoichiometric CT number calibration method using the newly developed Nakao20 model was applied to BNCT dose calculation. The results indicate the importance of calibrating the CT number to elemental composition for each individual CT scanner for the purpose of BNCT dose calculation along with the consideration of heterogeneity of the material composition inside the defined region of interest.

Automation to facilitate optimisation of breast radiotherapy treatments using EPID-based in vivo dosimetry

Objective. To use automation to facilitate the monitoring of each treatment fraction using an electronic portal imaging device (EPID) based in vivo dosimetry (IVD) system, allowing optimisation of breast radiotherapy delivery for individual patients and cohorts. Approach. A suite of in-house software was developed to reduce the number of manual interactions with the commercial IVD system, dosimetry check. An EPID specific pixel sensitivity map facilitated use of the EPID panel away from the central axis. Point dose difference and the change in standard deviation in dose were identified as useful dose metrics, with standard deviation used in preference to gamma in the presence of a systematic dose offset. Automated IVD was completed for 3261 fractions across 704 patients receiving breast radiotherapy. Main results. Multiple opportunities for treatment optimisation were identified for individual patients and across patient cohorts as a result of successful implementation of automated IVD. 5.1% of analysed fractions were out of tolerance with 27.1% of these considered true positives. True positive results were obtained on any fraction of treatment and if IVD had only been completed on the first fraction, 84.4% of true positive results would have been missed. This was made possible due to the automation that saved over 800 h of manual intervention and stored data in an accessible database. Significance. An improved EPID calibration to allow off-axis measurement maximises the number of patients eligible for IVD (36.8% of patients in this study). We also demonstrate the importance in selecting context-specific assessment metrics and how these can lead to a managable false positive rate. We have shown that the use of fully automated IVD facilitates use on every fraction of treatment. This leads to identification of areas for treatment improvement for both individuals and across a patient cohort, expanding the uses of IVD from simply gross error detection towards treatment optimisation.

Numerical simulation of the electromagnetic field in the secondary cooling zone of arc-shaped slabs

The magnetic field characteristics due to electromagnetic stirring in the secondary cooling zone of an extra-thick slab during continuous casting are numerically determined using Maxwell's equations, with particular emphasis on the distribution of magnetic induction intensity and electromagnetic force, as well as the influence of process parameters on the magnetic field. The orientation of the electromagnetic force is the same when the electromagnetic stirrers at the 30° and 60° posistions of the arc-shaped slab are powered in the same direction; otherwise, the orientation is opposite. The magnetic induction at the centre of the section of the stirrer's central axis at the 30° positio, as well as the current, frequency, and fitting formulae, are as follows: B = {0.075I(1/A)-0.3} mT and B = {-1.75f(1/Hz)+22} mT. The electromagnetic force and current fitting formula at the central point of the B-B section is F = {0.03168I2(1/A2)-03.762I(1/A)+326.7} N/m3, and the fitting formula of electromagnetic force and frequency at the centre point is divided into two segments. The first takes the form of a parabola: = {-21((f-4.3)-(1/Hz)2)+970} N/m3, and the second segment is negative linear: F = {-1.65f(1/Hz)+51.5} N/m3.

Diagnostic Instrument Design: Teleworking Efficiency Index

Purpose: To present the design of a new diagnostic tool called “Telework Efficiency Index” that is able to evaluate the performance of the telework modality for any business activity. Method: For the design of the telework efficiency index, it was necessary to reveal some current experiences of the phenomenon of telework in Argentina, carrying out a field investigation through surveys and in-depth interviews with three companies operating at national and international level, two of them belonging to the telecommunications and IT sector, and another, belonging to the tourism sector as a corporate agency. Results and conclusion: The field research carried out for the design of a new teleworking diagnostic tool, shows quite strong results of the benefits associated with the company and its workers. There is a better balance between work and family/personal activity in terms of a proportion of time spent on the order of 45% for work activities and 35% for family and personal leisure activities. í 83.33% of respondents say that the link in the ón labor relationship has improved since teleworking, and with respect to the link with their íworkñ 60% say that it has improved. In addition, 60% said they were á with teleworking, and the remaining 40% were very satisfied. Being that 50% states that the level of stress at work has decreased and has significantly improved their quality of life at the same time as their work performance. é. The biggest deficiency in 76.66% lies in the imperative need to educate and train the skills and abilities of people to perform telework optimally. The telework efficiency index represents a diagnostic tool that evaluates the performance of telework, taking as a central axis of analysis the person who exercises telework over other variables of lower incidence such as the technological infrastructure and the economic and financial aspects of organizations. Implications of research: A phenomenon of growing global trend is taken as a starting point, which emerges strongly in recent decades as a result of the great development of information and communication technologies in the productive and social field, and in particular, from the COVID-19 pandemic that has definitively consolidated telework as a new modality of work organization, which benefits all parties involved. In this framework, the design of a diagnostic tool "telework efficiency index" that evaluates the performance of telework is presented, and facilitates better strategic decisions in organizations in the new era that transits society and the productive sector. Originality/value: This study allows to present to the productive community a new diagnostic tool that evaluates the performance of telework, where the psychological and emotional aspects of the people willing to exercise telework over technological issues are placed in the center of the scene. This tool provides an original contribution of analysis to the discipline, considering telework as a disruptive methodology of work organization.

Posterior endpoint determination of the lumbar pedicle central axis on the anterior–posterior fluoroscopic image for pedicle screw insertion

The transpedicular procedure has been widely used in spinal surgery. The determination of the best entry point is the key to perform a successful transpedicular procedure. Various techniques have been used to determine this point, but the results are variable. This study was carried out to determine the posterior endpoint of the lumbar pedicle central axis on the standard anterior–posterior (AP) fluoroscopic images. Computer-aided design technology was used to determine the pedicle central axis and the posterior endpoint of the pedicle central axis on the posterior aspect of the vertebra. The standard AP fluoroscopic image of the lumbar vertebral models by three-dimensional printing was achieved. The endpoint projection on the AP fluoroscopic image was determined in reference to the pedicle cortex projection by the measurements of the angle and distance on the established X–Y coordinate system of the radiologic image. The projection of posterior endpoint of the lumbar pedicle central axis were found to be superior to the X-axis of the established X–Y coordinate system and was located on the pedicle cortex projection on the standard AP fluoroscopic image of the vertebra. The projection point was distributed in different sectors in the coordinate system. It was located superior to the X-axis by 18° to 26° at L1, while they were located superior to the X-axis by 12° to 14° at L2 to L5. The projections of posterior endpoints of the lumbar pedicle central axis were located in different positions on the standard AP fluoroscopic image of the vertebra. The determination method of the projection point was helpful for selecting an entry point for a transpedicular procedure with a fluoroscopic technique.

Fluid dynamics and mixing in a novel intermittently rotating bioreactor for CAR-T cell therapy: Spin-down from incomplete spin-up

This work explores the fluid flow and mixing within a new type of intermittently rotating bioreactor used for the automated manufacturing of CAR-T cell therapy products; CAR-T is a novel cell-based gene therapy which offers a single-dose cure for several forms of advanced blood cancer. The rotating cylinder bioreactor has a free surface and a liquid height to radius ratio of 0.5. Agitation is achieved via intermittent rotation of the entire vessel around its central vertical axis. No comprehensive engineering characterisation of the fluid dynamics in a bioprocessing context exists to date for this type of bioreactor. The present study examines the fluid dynamics and mixing during spin-down to rest following incomplete spin-up (i.e. the starting state of the fluid is not solid body rotation). Novel Particle Image Velocimetry (PIV) and Planar Laser-Induced Fluorescence (PLIF) data is presented, shedding light on the different transient flow regions inside the intermittently rotating bioreactor, and on the impact spin-up time has on the mixing efficiency of the subsequent spin-down stage. The results presented can be used to inform the design of a custom intermittent agitation pattern for any resembling cylinder bioreactors, the adoption of which could lead to higher yields and reduced costs for the cell expansion step of the manufacturing process.

Experimental analysis of lifelines in a 15,000 L bioreactor by means of Lagrangian Sensor Particles

This study employs Lagrangian Sensor Particles (LSPs) with a diameter of 40 mm equipped with a pressure sensor to investigate cell lifelines in a 15,000L stirred tank reactor (STR) with three Elephant Ear impellers. The Stokes number of the LSPs is approx. 0.004 on a macro-scale. The vertical probability of presence, axial velocity profiles, circulation time distributions, and residence time distributions are quantified to analyze single-phase mixing heterogeneities, detect hydrodynamic compartments and conduct a Lagrangian regime analysis. Results reveal a similarly distributed probability of presence in the vertical reactor center but emphasize the LSP’s sensitivity to fluctuating densities. Axial velocity distributions illustrate characteristic impeller-induced flow patterns, and circulation time distributions identify three compartments with comparatively shorter times in the axial center. Residence time distributions exhibit a similar compartmentalized profile. Moreover, the study estimates a potential oxygen deprivation zone for CHO cells in the upper compartment and demonstrates the LSP’s efficacy in characterizing impeller systems. Contrary to literature, the ratio of examined global mixing times to circulation times is 1.0, highlighting macro-scale mixing. The research underscores that LSPs offer crucial insights into industrial-scale STRs, specifically for determining hydrodynamic compartments without having optical access.

Investigation on tunnelling-induced soil pressure changes, a modified trapdoor test study

To investigate the failure mechanics and soil pressure redistribution in cohesive soil during the formation of the arching effect after tunnel excavation, a series of trapdoor tests were conducted on similarity material, and the tunnelling-induced soil movement was modeled. In addition, the moveable soil on the two sides of a tunnel was replicated by modifying the boundary condition of the classic trapdoor. Results indicated that as the trapdoor descended, the cracks extended outward to the ground when the cover ratio (depth to width) was 2, and extended upwards below the ground when the cover ratio was over 2. After the descent of the trapdoor, the unloading effect and arching effect were formed. Therefore, above the trapdoor, the vertical stress (radial stress for the trapdoor) decreased significantly while the tangential stress for the trapdoor increased. Due to the arching effect, the lateral pressure coefficient (K) at the central axis of the trapdoor increased, while it decreased above the two sides of the trapdoor. In the modified trapdoor device, the arching effect was weaker, and reduced the angle between the outermost crack and the horizontal plane, the tangential stress, and the K at the central axis of the trapdoor, and increased the K above both sides of the trapdoor and the range of the soil arch. In addition, in the classic trapdoor device, the arching effect was underestimated at small trapdoor displacements while it was overestimated at large trapdoor displacements. Therefore, the influence of boundary conditions in trapdoor devices should be considered when investigating underground excavation-induced soil deformation and stress redistribution. When calculating the soil pressure, the K should be determined according to the parameters of the soil, the span of the tunnel, and the deformation of the tunnel lining.

Stable three-dimensional vortex families consistent with Jovian observations including the Great Red Spot

Detailed observations of the velocities of Jovian vortices exist at only one height in the atmosphere, so their vertical structures are poorly understood. This motivates this study that computes stable three-dimensional, long-lived planetary vortices that satisfy the equations of motion. We solve the anelastic equations with a high-resolution pseudo-spectral method using the observed Jovian atmospheric temperatures and zonal flow. We examine several families of vortices and find that constant-vorticity vortices, which have nearly uniform vorticity as a function of height, and horizontal areas that go to zero at their tops and bottoms, converge to stable vortices that look like the Great Red Spot (GRS) and other Jovian anticyclones. In contrast, the constant-area vortices proposed in previous studies, which have nearly uniform areas as a function of height, and vertical vorticities that go to zero at their tops and bottoms, are far from equilibrium, break apart, and converge to constant-vorticity vortices. Our late-time vortices show unexpected properties. Vortices that are initially non-hollow become hollow (i.e. have local minima of vertical vorticity at their centres), which is a feature of the GRS that cannot be explained with two-dimensional simulations. The central axes of the final vortices align with the planetary spin axis even if they align initially with the local direction of gravity. We present scaling laws for how vortex properties change with the Rossby number and other non-dimensional parameters. We prove analytically that the horizontal mid-plane of a stable vortex must lie at a height above the top of the convective zone.

The impact of successive laser shock peening on surface integrity and residual stress distribution of laser powder-bed fused stainless steel 316L

Abstract The utilization of laser shock peening (LSP) in laser powder bed fused (LPBF) stainless steel (SS) 316L components enhances the mechanical characteristics and operational lifespan of the product quality through a significant reduction of residual stress and a noticeable increase in roughness parameters. The key objective of the study is to analyze the influence of consecutive laser shock peening (LSP) without ablative coating and low pulse energy on the surface properties, residual stress distribution, and microhardness of samples produced by LPBF with SS316L material. The surface quality of the sample subjected to consecutive laser shock peening shows a slight deterioration in its condition. This can be attributed to the combined impact of ablative surface and surface damage resulting from the production of high-energy plasma. However, the implementation of successive LSP results in a distinctive enhancement of compressive residual stresses (CRS) that are evenly distributed throughout the central axis and sharp edges. In contrast, the as-built condition exhibits non-uniform stress magnitudes. CRS observed in each LSP iteration exhibits a notable increase, reaching a maximum magnitude of −389 MPa compared to the initial stress level of 165 MPa in the as-built sample. This enhancement can be attributed to the repetitive impact of shock waves on the surface, leading to the formation of plastic deformation. The refinement of surface grains and the presence of favorable residual stresses were proven by the utilization of x-ray diffraction (XRD) studies and the Cos α plot. The XRD investigation also indicated the absence of any newly formed phases or secondary phases. A significant enhancement in microhardness was observed, with an increase of 58.3% achieved after the third consecutive peening process. The successive LSP samples displayed a gradual improvement in electrochemical behavior. Though the amplitude parameters increased after LSP, the increase in wear rate was observed.

Game and Identity Nasa, a case of the Carrizales agricultural educational institution el from Corinto, Cauca

The following article comes from an investigative study that has as its object the cultural identity in the enrichment through the game, since the diversity and complexity, positions the human being as the central axis, in the sixth grade of the secondary school in the municipality of Corinto Cauca, Corregimiento de los Andes, at the Carrizales Agricultural Educational Institution, (2022-2023). In this sense, it is a work that is oriented to the search for the strengthening of respect for cultural identity in a given territory, the Nasa indigenous peoples have historically been fighting for their survival, recovery and respect for their cultural identity. This article focused on an action-research, because it was based on specific aspects based on the reality of the context, according to Suarez (2002) it is a research that aims to improve education by changing practices and that allows learning thanks to the reflective analysis of the consequences that it generates, for which it became necessary to attend to the nucleus of well-being and culture that is experienced as an educational practice (ancestral knowledge and wisdom) that strengthens coexistence, respect for other ways of thinking and acting.

Estado del Arte sobre Comunidades de Aprendizaje Profesional en las prácticas de gestión escolar: (2020-2023)

In the current educational context, characterized by its dynamism and globalization, Professional Learning Communities (PLCs) stand out as vital for the development and improvement of educational management. This article reviews recent literature to establish how PLCs can concretize effective management practices, with a particular focus on the role of the principal as a leader in this process. Using a document review methodology based on a systematic search of academic sources, 30 articles published between 2020 and 2023 were analyzed, including 17 of them for specific relevance. The results indicate that PLCs are effective in improving collaboration, teacher professional development and teaching quality, highlighting the importance of adaptive and culturally sensitive managerial leadership that is formed in collaborative spaces. Challenges identified include the need for structural support and role clarity during educational change. The conclusion highlights the relevance of PLCs in forming strategic alliances and implementing actions to respond to the needs of each educational context, emphasizing continuous improvement and collaboration as central axes.

Cone-Beam CT Images as an Indicator of QACT During Adaptive Proton Therapy of Extremity Sarcomas

PurposePeriodic quality assurance CTs (QACTs) are routine in proton beam therapy. In this study, we tested whether the necessity for a QACT could be determined by evaluating the change in beam path length (BPL) on daily cone-beam CT (CBCT). Patients and MethodsIn this Institutional Review Board–approved study, we retrospectively analyzed 959 CBCT images from 78 patients with sarcomas treated with proton pencil-beam scanning. Plans on 17 QACTs out of a total of 243 were clinically determined to be replanned for various reasons. Daily CBCTs were retrospectively analyzed by automatic ray-tracing of each beam from the isocenter to the skin surface along the central axis. A script was developed for this purpose. Patterns of change in BPL on CBCT images were compared to those from adaptive planning using weekly QACTs. ResultsSixteen of the 17 adaptive replans showed BPL changes ≥4 mm for at least 1 of the beams on 3 consecutive CBCT sessions. Similarly, 43 of 63 nonadaptively planned patients had BPL changes <4 mm for all of the beams. A new QACT criterium of a BPL change of any beam ≥4 mm on 3 consecutive CBCT sessions resulted in a sensitivity of 94.1% and a specificity of 68.3%. Had the BPL change been used as the QACT predictor, a total of 37 QACTs would have been performed rather than 243 QACTs in clinical practice. ConclusionThe use of BPL changes on CBCT images represented a significant reduction (85%) in total QACT burden while maintaining treatment quality and accuracy. QACT can be performed only when it is needed, but not in a periodic manner. The benefits of reducing QACT frequency include reducing imaging dose and optimizing patient time and staff resources.

Study on Resin-based 3D Printed Product for Spin Casting Mold Making

Spin casting (centrifugal rubber mold casting) is well known process to produce castings by utilizing inertia. A vulcanized rubber mold is typically used by spinning it at an optimum speed along its central axis. There are many factors influence the quality of casting product, including the quality of mold, the temperature of molten material, the speed and duration of rotation, as well as the pressure upon the mold. This research aims to investigate the quality of casting product when a resin-based 3D printing is utilized to make a model for vulcanized rubber mold. The model is designed by using CAD software and printed layer by layer by using Selective Laser Sintering (SLS) method. Curing process is employed in order to harden the model before placed in the disc-shape silicone rubber. The rubber is then vulcanized so that the mold is formed. Standard edge gate and straight runner are then made to let the molten material flow during casting process. Zinc alloy is used as raw material in the casting process with five variations of rotation speed. Based on the experiment results it is observed that the resin-based 3D printed product can be used as a master model in rubber mold making with some limitations. The resin could not maintain its shape due to the high temperature and pressure during vulcanization process. However, for simple design without any need of very small and detail features, the resin-based 3D printed product still can be used as an alternative.

Self-similar solutions to a multidimensional singular heat equation with power nonlinearity

The paper deals with the construction of exact solutions to a singular heat equation with power nonlinearity in the case of numerous independent variables with spatial (e.g. axial or central) symmetry. A new class of self-similar solutions is proposed, which reduce to solving the Cauchy problem for a second-order nonlinear ordinary differential equation having singularities at the higher derivative with respect to the required function and/or the independent variable. The ordinary differential equation is studied in two ways: analytically and numerically. The analytical study uses a truncated Taylor series with recurrently computed coefficients, for which explicit formulas are obtained. The numerical solution to the problem uses an iteration algorithm based on the collocation method and radial basis functions. The numerical analysis shows the convergence of the proposed numerical algorithm and its sufficient accuracy enabling one to use the found self-similar solutions to verify approximate solutions to the original heat equation. Besides, the numerical analysis has allowed the radius of convergence of the constructed Taylor series to be evaluated. The form of the constructed self-similar solutions, namely their unboundedness near the symmetry center (axis), enables us to study the behavior and exactness of the numerical solutions to the nonlinear singular parabolic-type equation that have been obtained by the stepwise solution method proposed by us earlier and possess the same property.

Hydrodynamic metamaterial redirector for steering fluid flow in pipelines with arbitrary curvatures

Hydrodynamic metamaterial redirector for steering fluid flow in pipelines with arbitrary curvatures

Rozwiązanie problemu tworzenia się zatorów w rurociągach podczas transportu gazu poprzez proces automatycznego strumieniowania

The article presents the application of autoejection process to ensure efficient operation of pipeline systems and gas separation installations when it is impossible to remove and utilize the condensate from the pipelines. Thus, in the suggested ejector, a single common stream is separated into two streams, i.e., an active and a passive stream, as opposed to two separate independent streams in existing ejection devices. As a result, we refer to such an ejection process as autoejection, or a self-ejection process. Such a procedure is run in the pipeline with the goal of blowing and dusting the liquid phase through the central high-velocity nozzle in circumstances of mass blocking and coating rather than expelling the liquid from the pipes. On the cross-sectional area of the belts, the velocity profiles of flows in laminar and turbulent regimes are known to differ greatly from one another. The adhesion forces acting from the tube's central axis outwards, towards its walls cause the flow rate to decrease. There is a cross-sectional interaction of flows in this mode, according to experimental studies of turbulent flows. As a result, compared to the laminar domain, the flow velocities in this regime are more equally distributed across the cross-section of the flow, and their values are roughly equal to the flow's average value. In this case, based on the dependences of the flow ∆p = f(W), it is known from the calculations and the table that at such velocity limits of the flows, the “braking” pressure (p0) of the liquid coating on the pipe walls corresponds to the maximum velocity of the central gas flow. The autoejection process can occur due to the difference between the static pressures. Unsaturated absorbent coatings can be blasted off the tube absorber's walls using this technique and blended back into the main gas stream. Gas-liquid autoejectors installed along the pipe absorber's length make it possible to use this method. The purpose and principles of autoejectors’ operation are considered and a perspective of their application in tube absorbers is noted.

Dismantling Colonial Epistemicide: Exorcism and Transmutation in Brazilian Contemporary Art

In recent years, many visual artists working in the intersection between art and spirituality gained visibility on the Brazilian artistic scene. The inspiration for this essay is found in the shifts that this production allows us to discern in relation to the very notion of art. Mobilizing practices and rituals linked to Afro-Indigenous religions and ancestralities, these artists dismantle the project of colonial epistemicide insofar as they challenge categories which are fundamental to the structuring of Western reason. Artists Ayrson Heráclito and Castiel Vitorino Brasileiro, who have spirituality as a central axis of their poetics, constitute the artistic corpus of this research.