Radial Pattern Research Articles

Climatic regulation of leaf and cambial phenology in Quercus pubescens: Their interlinkage and impact on xylem and phloem conduits

Increased frequency and severity of stressful events affects the growth patterns and functioning of trees which adjust their phenology to given conditions. Here, we analysed environmental effects (temperature, precipitation, VPD and SWC) on the timing of leaf phenology, seasonal stem radial growth patterns, and xylem and phloem anatomy of Quercus pubescens in the sub-Mediterranean in the period 2014–2019, when various adverse weather events occurred, i.e. spring drought in 2015, summer fire in 2016 and summer drought in 2017. Results showed that the timings of leaf and cambium phenology do not occur simultaneously in Q. pubescens, reflecting different environmental and internal constraints. Although year-to-year variability in the timings of leaf and cambial phenology exists, their chronological sequence is fairly fixed. Different effects of weather conditions on different stages of leaf development in spring were observed. Common climatic drivers (i.e., negative effect of hot and dry summers and a positive effect of increasing moisture availability in winter and summer) were found to affect the widths of xylem and phloem increments with more pronounced effect on late formed parts. A legacy effect of the timing of leaf and cambial phenology of the previous growing season on the timing of phenology of the following spring was confirmed. Rarely available phloem data permitted a comprehensive insight into the interlinkage of the timing of cambium and leaf phenology and adjustment strategies of vascular tissues in Mediterranean pubescent oak to various environmental constraints, including frequent extreme events (drought, fire). Our results suggest that predicted changes in autumn/winter and spring climatic conditions for this area could affect the timings of leaf and stem cambial phenology of Q. pubescens in the coming years, which would affect stem xylem and phloem structure and hydraulic properties, and ultimately its performance.

The morphogenesis of porcine femoral head mammillary processes: A structural mechanism of biomechanical stability.

The capital femoral physis is a growth plate located between the head of the femur and femoral neck, which forms a temporary joint where growth plate cartilage is converted to bone by endochondral ossification. The bone-cartilage-bone interface develops a unique radial pattern of interdigitating mammillary processes that interlock the femoral head with the metaphysis, increasing biomechanical stability. The arrangement of these mammillary processes may not be a random occurrence and likely serves to provide mechanical mechanisms to enhance biomechanical stability. In this study, we provide a qualitative and quantitative analysis of porcine femoral head mammillary processes and focus on the analysis of six key points of development: the epiphyseal tubercle, epiphyseal cupping, growth plate slope angles, expansion of the epiphyseal subchondral bone plate, epiphyseal elongation, and the emergence of smaller, radially arranged mammillary processes. We introduce a metric of surface roughness analysis to quantify mammillary processes and apply it to analyze the development of the observed radial pattern of peripheral mammillary processes from birth to adolescence. We hypothesized that these processes develop to form a radial pattern with some degree of periodicity beginning relatively early in development of the joint and increase in prominence with age and weight of the animal. These findings may have important implications in the early diagnosis and treatment of the hip disorder slipped capital femoral epiphysis (SCFE). Underdevelopment of femoral head mammillary processes may reduce joint stability and could be a risk factor in SCFE.

Computational Analysis of Wall Shear Stress Patterns on Calcified and Bicuspid Aortic Valves: Focus on Radial and Coaptation Patterns

Calcification and bicuspid valve formation are important aortic valve disorders that disturb the hemodynamics and the valve function. The detailed analysis of aortic valve hemodynamics would lead to a better understanding of the disease’s etiology. We computationally modeled the aortic valve using simplified three-dimensional geometry and inlet velocity conditions obtained via echocardiography. We examined various calcification severities and bicuspid valve formation. Fluid-structure interaction (FSI) analyses were adapted using ANSYS Workbench to incorporate both flow dynamics and leaflet deformation accurately. Simulation results were validated by comparing leaflet movements in B-mode echo recordings. Results indicate that the biomechanical environment is significantly changed for calcified and bicuspid valves. High flow jet velocities are observed in the calcified valves which results in high transvalvular pressure difference (TPG). Wall shear stresses (WSS) increased with the calcification on both fibrosa (aorta side) and ventricularis (left ventricle side) surfaces of the leaflet. The WSS distribution is regular on the ventricularis, as the WSS values proportionally increase from the base to the tip of the leaflet. However, WSS patterns are spatially complex on the fibrosa side. Low WSS levels and spatially complex WSS patterns on the fibrosa side are considered as promoting factors for further calcification and valvular diseases.

Different tree-ring width sensitivities to satellite-based soil moisture from dry, moderate and wet pedunculate oak (Quercus robur L.) stands across a southeastern distribution margin

Associations of pedunculate oak (Quercus robur L.) radial growth with satellite-based soil moisture (SM) during the intensive tree growth period over a 30-year time span (1980–2010) were analyzed. This study included tree-ring width (TRW) chronologies from 22 stands located in four southeastern (SE) European countries (Slovenia, Croatia, Serbia and Bulgaria), which were grouped into three wetness groups (WGs): dry (<650 mm), moderate (650–750 mm), and wet (>750 mm), following the annual sum of precipitation. High correlation strengths during the intensive growth period—late spring and early summer months (April to June) was noted, which was opposite to the trend in late summer months. Variations in detrended TRW (TRWi) sensitivity to SM were also observed among the WGs. Specifically, the TRWi chronologies from the dry and wet WGs provided a greater number of significant correlations (p < 0.01) than trees from the moderate WG did. In wetter stands, TRWi correlated more negatively in the wettest (spring) months, while the correlation was weaker in summer months; these trends were opposite to those of trees growing in drier conditions that had the strongest responses to SM. A generalized additive mixed model (GAMM) based on 38 variables indicated that the fit for SM and radial growth was as strong as the fits for other traditionally measured parameters (temperature, precipitation, and river water level) and calculated drought indices (standardized precipitation index and the Ellenberg index) and TRW. Additionally, radial growth chronologies from drier sites had stronger fits with surrounding environmental factors. In conclusion, our findings suggest that SM can potentially be used as a reliable remote sensing indicator of the soil wetness in oak forests, which affects tree productivity and radial growth patterns and provides a new opportunity in dendrochronology research on larger scales.

Term or Phrase Usage and Contextual Meaning: A Reexamination of Semantic Issues in Translation

It has been observed that “words do not have meanings but rather meanings have words.” But even more, words and phrases, usually thought of as the basic units of meaning, actually should be seen as having only usages within contexts. These contexts themselves are the elements of communication that activate mental and bodily states and processes, and can be properly thought of as the construal of meaning. Sometimes these contexts of usage are shaped by phonological or grammatical patterns (see B. Bergen), sometimes by sociological factors such as reciprocity (see E. Goffman), and of course most commonly by lexical (usually radial) patterns and categories (traditionally presented as “semantic domains”). Cognitive linguists (e.g., Lakoff, Turner) have been hinting at something like this for a long time, but a clear restatement of what constitutes semantics is overdue.

Systolic finger pressures during an Allen test before hemodialysis access construction predict severe postoperative hand ischemia

ObjectiveThe Allen test is a simple bedside method for determining hand perfusion. Earlier studies in patients on hemodialysis (HD) found that an Allen test before access construction did not predict hand ischemia later on. The study aimed to assess whether an Allen test combined with finger plethysmography before access surgery has a potential to predict the onset of severe HD access induced distal ischemia (HAIDI). MethodsBefore the first access construction in patients with chronic kidney disease, systolic finger pressures (Pdig, in millimeters of mercury) were obtained using plethysmography at rest and after serial compression of the radial and ulnar artery. A decrease in Pdig (∂Pdig) was calculated as the difference between Pdig-rest and Pdig-compression. The severity of postoperative HAIDI was graded as suggested by a 2016 consensus meeting. Patients with a severe type of HAIDI (grade 2b-4, intolerable pain, invasive treatment required) were compared with controls not having HAIDI. ResultsA total of 105 patients with chronic kidney disease (mean age 70 ± 13 years; 65% males) receiving their first access between January 2009 and December 2018 in one center fulfilled study criteria. Ten patients (10%) developed severe HAIDI at 14 ± 5 months after access construction. Before access creation, all patients with HAIDI demonstrated a radial or ulnar dominant hand perfusion pattern compared with just 57% in controls (P = .010). Compression resulted in an almost two-fold greater ∂Pdig in patients with severe HAIDI (51 ± 8 mm Hg vs 27 ± 3 mm Hg; P = .005). A 40-mm Hg ∂Pdig cut-off value demonstrated optimal tests characteristics (sensitivity of 80%, specificity of 77%, positive predictive value of 27%, negative predictive value of 97%) indicating a 10 times greater risk of developing severe HAIDI. ConclusionsFinger plethysmography quantifying ∂Pdig during an Allen test before access creation may identify patients who have a substantially increased risk of developing severe hand ischemia after HD access surgery.

Shrinkage pattern assessment for black pine juvenile wood delimitation

Juvenile wood is associated with shrinkage and a high probability of warping and checks in end products, reducing their value and even causing them to be rejected for structural purposes. This work studies the variations in yearly shrinkage caused when wood passes from green to dry state. The methodology proposed is based on the juvenile wood (JW) location using annual shrinkage variations. Pinus nigra Arn. grown using different silviculture techniques was chosen for study because its wood is characterized by severe shrinkage problems. This characteristic is analyzed in the radial and angular directions, of which the latter is a different methodology for evaluating warping problem rather than the commonly used ratio of anisotropy. It takes into account the annual measurements obtained from a disc cut from the tree trunk at various heights. The results were compared with the segregated JW and mature wood (MW) area obtained by radial densitometry pattern variation methodology. The results show that radial shrinkage is higher near the pith but stabilizes earlier (3–7 rings) than angular shrinkage (9–11 rings). Nevertheless, the opposite initial radial pattern occurs in angular shrinkage, which is low near the pith but increases annually towards the bark until it stabilizes. No clear effect of height in the tree when comparing the radial shrinkage patterns obtained along the bole can be defined. Silviculture practices have no significant influence on shrinkage percentage. Shrinkage and densitometry methodologies show differences in the quantification of JW volume percentage between JW and MW estimation. Results show that radial shrinkage pattern methodology, which is associated with warping problems, classifies a higher tree volume as good quality for end uses in comparison to the use of radial densitometry pattern methodology. On the other hand, if classified by radial densitometry pattern variation, warping problems associated with JW should not be a problem when sawn.

Localised Radial Patterns on the Free Surface of a Ferrofluid

This paper investigates the existence of localised axisymmetric (radial) patterns on the surface of a ferrofluid in the presence of a uniform vertical magnetic field. We formally investigate all possible small-amplitude solutions which remain bounded close to the pattern’s centre (the core region) and decay exponentially away from the pattern’s centre (the far-field region). The results are presented for a finite-depth, infinite expanse of ferrofluid equipped with a linear magnetisation law. These patterns bifurcate at the Rosensweig instability, where the applied magnetic field strength reaches a critical threshold. Techniques for finding localised solutions to a non-autonomous PDE system are established; solutions are decomposed onto a basis which is independent of the radius, reducing the problem to an infinite set of nonlinear, non-autonomous ODEs. Using radial centre manifold theory, local manifolds of small-amplitude solutions are constructed in the core and far-field regions, respectively. Finally, using geometric blow-up coordinates, we match the core and far-field manifolds; any solution that lies on this intersection is a localised radial pattern. Three distinct classes of stationary radial solutions are found: spot A and spot B solutions, which are equipped with two different amplitude scaling laws and achieve their maximum amplitudes at the core, and ring solutions, which achieve their maximum amplitudes away from the core. These solutions correspond exactly to the classes of localised radial solutions found for the Swift–Hohenberg equation. Different values of the linear magnetisation and depth of the ferrofluid are investigated and parameter regions in which the various localised radial solutions emerge are identified. The approach taken in this paper outlines a route to rigorously establish the existence of axisymmetric localised patterns in the future.

Shape discrimination in peripheral vision: Addressing pragmatic limitations of M-scaling radial frequency patterns

Peripheral worsening in shape discrimination (SD) can be compensated by size-scaling of peripheral stimuli. However, such scaling results in production of large stimuli that occupy a vast range of eccentricities. We used six proportionally decreasing spatial scales to address this pragmatic limitation and to explore how shape discrimination varies with radius in the nasal visual field. Five participants with normal vision discriminated circles and radial frequency (RF) patterns presented nasally to the fixation point at 5°, 10°, 15° and 20°. Stimuli were scaled with the nasal cortical magnification factor (nCMF) from a central stimulus in six spatial scales, which varied from 0.125 to 1, where 1 corresponded to 1.2° radius. Thresholds expressed in Weber fractions remained constant at eccentricities up to 20° regardless of the spatial scale. Weber fractions for the smaller spatial scales (0.125–0.5) were higher and more variable than for the larger spatial scales (0.75–1), yet still constant across periphery. The results provide evidence that peripheral shape discrimination is constrained by low-level properties, such as eccentricity, and can be predicted by the cortical magnification theory. However, above the peripheral modulation resolution limits, RF shape discrimination is based on the proportion between the modulation amplitude and the radius for larger scales (0.75–1), and demonstrates peripheral scale invariance for these stimuli. For eccentric shape discrimination tests, stimuli with low spatial frequency, high contrast, and radii corresponding to SS 0.75–0.875 should be used to ensure constant Weber fractions, small variability, and peripheral stimuli that are not excessively magnified.

Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods.

The results of an experimental program on shear-strengthening of flat slabs using Glass Fiber Reinforced Polymer (GFRP) rods are presented. A total of seven specimens were tested under an upward concentric monotonic loading until failure. One specimen served as a control and was tested without any modification. The remaining six specimens were strengthened with post-installed GFRP rods in single (SG), double (DB), and radial (RD) patterns within shear critical parameters around the centric column. The results of this experimental study suggest that GFRP rods are capable of enhancing both the peak load and deformation capacity. Furthermore, brittle failure associated with punching shear failure was successfully avoided by all strengthening patterns. Of all of the patterns, the RD pattern resulted in maximum peak load increase and corresponding deformation capacity while the lowest bound was created by the SG pattern. The results suggested that SG, DB and RD patterns enhanced ultimate loads up to 9.1, 11.3 and 15.7% while corresponding deflections increased up to 109, 136 and 154%. Strain measurement on flexural reinforcement suggested that all strengthened specimens were able to withstand higher longitudinal strains than yield. It was further shown that reducing the spacing between the GFRP rods efficiently enhanced peak loads, nevertheless, neither this change was proportional, nor did it result in an enhanced energy dissipation capacity. In the end, recommendations of American Concrete Institute (ACI) for the shear strength of two-way systems were modified to incorporate the contributions from GFRP rods. The results indicate that the proposed analytical approach provides an excellent match with the experimental results.

Low-energy interference structure with attosecond temporal resolution

Accessing precisely the phase variation of electronic wave-packet (EWP) provides unprecedented spatiotemporal information of the microworld. A radial interference pattern at near-zero energy has been widely observed in experiments of strong-field photoionization. Here we report an experimental and theoretical investigation of this low-energy interference structure (LEIS) in mid-infrared laser fields. We clarify that the LEIS arises due to the soft-recollision mechanism, which was previously found to play a pivotal role in producing the pronounced low-energy structure. Specifically, the LEIS is induced by the interference between direct and soft-recollision EWPs launched within a 1/18 laser-cycle time scale in our experiments. Our result opens a promising new avenue for retrieving the structure and dynamics of EWPs in atoms and molecules with attosecond time resolution.

A novel method for successful induction of interdigitating process formation in conditionally immortalized podocytes from mice, rats, and humans

Formation of processes in podocytes is regarded as the hallmark of maturity and normal physical condition for the cell. There are many accumulated findings about molecular mechanisms that cause retraction of podocyte processes; however, there is little knowledge of the positive mechanisms that promote process formation in vitro, and most previous reports about this topic have been limited to low-density cultures. Here, we found that process formation can be induced in 100% confluent cultures of conditionally immortalized podocytes in mouse, rat, and human species by combining serum depletion and Y-27632 ROCK inhibitor supplementation on the scaffold of laminin-521(L521). We noted the cytoskeletal reorganization of the radial extension pattern of vimentin filaments and downregulation of actin stress fiber formation under that condition. We also found that additional standard amount of serum, depletion of ROCK inhibitor, or slight mismatch of the scaffold as laminin-511(L511) hinder process formation. These findings suggest that the combination of reduced serum, podocyte-specific scaffold, and intracellular signaling to reduce the overexpression of ROCK are required factors for process formation.

Radial shearing speckle pattern interference system based on a spatial light modulator.

We propose a new radial shearing speckle pattern interference system. The introduction of radial shearing and the four-step temporal phase shift are realized using a spatial light modulator to modulate the phase information of the light wavefront. The modulation mode of the spatial light modulator is controlled by programming, and thus the shearing information can be adjusted quickly and arbitrarily according to the actual measurement needs. The interference system no longer has the requirement of the defect direction in nondestructive testing and can simultaneously realize the accurate detection of defects in all directions. The basic principle of radial shearing speckle pattern interferometry and the introduction method of radial shearing are described, and the system feasibility and practicability are verified by experiments.

Gaze patterns during presentation of fixed and random phase radial frequency patterns.

Radial frequency (RF) patterns, circles which have had their radius modulated as a function of their polar angle, have been used in the examination of the integration of contour information around closed contour patterns. Typically, these patterns have been presented in a random orientation from trial-to-trial in order to maintain spatial uncertainty as to the location of the deformation on the pattern, as it may affect observer strategy and performance. However, the effect of fixed and random orientation (phase) on observer gaze strategies used to discriminate RF patterns has not been directly tested. This study compared fixation patterns across four conditions: fixed phase single cycle; random phase single cycle; fixed phase three cycle; and random phase three cycle RF3 patterns. The results showed that observers fixated on the known location of deformation for the fixed phase single cycle condition but used a more central fixation for the other three conditions. This strategy had a significant effect on observer thresholds for the fixed phase single cycle condition, with greater adherence to the strategy resulting in lower thresholds. It was also found that for the single cycle patterns observers tended to fixate on different locations on the pattern: on the maximum orientation difference from circular for the fixed phase pattern; and on the point of maximum curvature for the random phase pattern. These differences in gaze patterns are likely driven by the underlying local or global processing of the fixed or random phase single cycle patterns, respectively.

Navigated single-capture 3D and cross-sectional wide-field OCT of the mid and peripheral retina and vitreoretinal interface.

Assess the mid and peripheral neuroretina and vitreoretinal interface using a novel Navigated Single-Capture 3D and Cross-Sectional Wide-Field Swept-Source Optical Coherence Tomography (WF SS-OCT) technology with correlation to Multi-Wavelength Ultra-Widefield Imaging (MW UWFI) and Histopathology reference. Retrospective observational study. A total of 74 patients (148 eyes) were imaged using WF SS-OCT and Navigated Single-Capture twelve 23 mm cross-sectional radial scan pattern at 15° intervals. Image diagnosis included: congenital hypertrophy of the retinal pigment epithelium, choroidal nevus, ora serrata pearls, retinal tuft, lattice, snail track, cobblestone degeneration, retinal hole, retinal tear, degenerative retinoschisis, peripheral laser retinopexy, white without pressure, vitreous floaters, subclinical peripheral rhegmatogenous retinal detachment (RD), and tractional RD in proliferative diabetic retinopathy. WF SS-OCT images were correlated with MW UWFI and histopathological references where available. WF SS-OCT successfully imaged structural features in all diagnoses with significant improvement in diagnostic capability and increased the diagnosis of specific features such as vitreoretinal attachment, full thickness hole or tear and subretinal fluid. Histopathological correlation was available for five (5) different peripheral retinal pathologies imaged by both WF SS-OCT and MW UWFI and good anatomical correlation was observed in all diagnosis. Navigated Single-Capture 3D and Cross-Sectional WF SS-OCT provides detailed anatomic information of the mid and peripheral neuroretina and vitreoretinal interface, allowing early recognition of vision-threatening features that may influence clinical management, particularly in an era of telemedicine or when there is limited or no access to Indirect Ophthalmoscopy with 360° Scleral Indentation.

RADLER – A UNICYCLE AS A LOW-COST RADIAL LASER SCANNER

Abstract. In recent years a wide range of 3D multi sensor systems for various applications has been proposed. Each of them has its own benefits and limitations. This paper proposes a modified unicycle with a 2D laser profiler attached to the wheel axle, thus creating a radial 3D scanning pattern. This novel low-cost device combines the advantages of wheeled scanning equipment with those of wearable or hand-held devices. After presenting the hardware setup and the sensor integration, the results are evaluated using four test scenarios and a terrestrial laser scanner for comparison.

Microperimetry Hill of Vision and Volumetric Measures of Retinal Sensitivity.

PurposeMean retinal sensitivity is the main output measure used in microperimetry. It is, however, of limited use in patients with poor vision because averaging is weighted toward zero in those with significant scotomas creating an artificial floor effect. In contrast, volumetric measures avoid these issues and are displayed graphically as a hill of vision.MethodsAn open-source program was created to manipulate raw sensitivity threshold data files obtained from MAIA microperimetry. Thin plate spline interpolated heat maps and three-dimensional hill of vision plots with an associated volume were generated. Retrospective analyses of microperimetry volumes were undertaken in patients with a range of retinal diseases to assess the qualitative benefits of three-dimensional visualization and volumetric measures. Simulated pathology was applied to radial grid patterns to investigate the performance of volumetric sensitivity in nonuniform grids.ResultsVolumetric analyses from microperimetry in RPGR-related retinitis pigmentosa, choroideremia, Stargardt disease, and age-related macular degeneration were analyzed. In simulated nonuniform testing grids, volumetric sensitivity was able to detect differences in retinal sensitivity where mean sensitivity could not.ConclusionsVolumetric measures do not suffer from averaging issues and demonstrate superior performance in nonuniform testing grids. Additionally, volume measures enable detection of localized retinal sensitivity changes that might otherwise be undetectable in a mean change.Translational RelevanceAs microperimetry has become an outcome measure in several gene-therapy clinical trials, three-dimensional visualization and volumetric sensitivity enables a complementary analysis of baseline disease characteristics and subsequent response to treatment, both as a signal of safety and efficacy.

Modeling transient pressure behaviour of a multi-fractured horizontal well in a reservoir with an arbitrary boundary and different fracture networks by considering stress-sensitive effect

Combining horizontal drilling together with hydraulic fracturing greatly improves the economic viability of exploiting a tight reservoir, while the stress-sensitive effect raises the significant difficulty to accurately evaluate its well performance. In this paper, a semi-analytical model is proposed to evaluate transient pressure behaviour of a multi-fractured horizontal well (MFHW) in a naturally fractured reservoir with an arbitrary boundary and different fracture networks under stress-sensitive effect. More specifically, the boundary element method coupled with the Pedrosa's transform formulation is used to obtain accurate solutions of the nonlinear equations incorporated with stress-sensitive effect in an arbitrary-shaped reservoir with single-zone or two-zone matrix subsystems. Meanwhile, the Laplace-transform finite difference method can be utilized to semi-analytically deal with the nonlinear fracture subsystems consisting of primary, secondary, and natural fractures by dividing complex fracture networks into small fracture segments. The convergence-skin effect is then introduced to represent the radial flow pattern in hydraulic fractures near a horizontal wellbore. Not only can the effects of stress-sensitivity in the matrix and different fracture subsystems be respectively examined, but also the corresponding pressure responses together with pressure derivative curves are obtained. Such coupled theoretical formulations have been verified and then extended for field applications. The semi-analytical solution is found to be more accurate and reasonable than the solution with the uniform permeability modulus, while the stress-sensitivity has a dominant impact on the intermediate- and late-time flow periods. The convergence-skin effect can be aggravated in the late-time period by considering the inherent stress-sensitivity in a hydraulic fracture, especially at low fracture conductivity. Based on the sensitivity analysis associated with different networks, the initial fracture conductivity in primary and secondary fractures imposes a great impact on the early-stage bilinear flow and fluid feed regimes, while the initial fracture conductivity in natural fractures makes a difference to the transient pressure response in the transition flow regime. As the minimum fracture conductivity in the primary fractures decreases, such an influence becomes more dominant during the late-time flow period. However, the minimum fracture conductivity in secondary and natural fractures has an inappreciable effect on the flow regime. In the late-time flow period, the effect of boundary shape becomes more obvious on the type curves, especially for a relatively small reservoir compared with the size of a horizontal well intercepted by multiple hydraulic fractures. For a reservoir with two-zone systems, the smaller the mobility ratio in the two zones is, the earlier the boundary-dominated flow in the outer zone will commence. Not only does this study facilitate understanding the respective contribution of stress-sensitivity and convergence-skin effect on the well production, but also the newly proposed models can be applied to optimally design a hydraulic fracturing operation under various constraints.

CFD Analysis of Modified Rushton Turbine Impeller

Mixing units is one of the prime components in various chemical processing industries. The mixing equipment produces a product by combing different liquids at various properties. Generally, the mixing units are axial and radial flow types. The rushton turbine is one of the radial flow types and had higher power number due to fluid resistance as disadvantage. This works aims to investigate the four bladed rushton turbine impellers at eight angles for finding optimum power without compromising radial flow patterns. The shaft eccentricity hydrodynamics effect is also analysed on the unbaffled stirred vessels. The variance of eccentric and coaxial agitation is clearly evaluated on the several power number and impeller blade angle by experimental and numerical analysis. The CFD analysis is made on the mixing chamber to find the optimum inputs of the mixing chamber numerically by varying the blade angles.

Temperature impact on linear and radial wormhole propagation in limestone, dolomite, and mixed mineralogy

The temperature has a significant impact on acid stimulation efficiency in carbonate reservoirs. To fully understand its effect, this study utilizes a two-scale continuum model coupled with heat transfer. The study investigated the importance of the heat of reaction, injected acid temperature, and reservoir temperature on wormhole propagation and treatment efficiency. This research's novelty stems from its application to limestone, dolomite, and combined mineralogy in radial and linear flow patterns. It also investigated the role of vugs on acidizing efficiency in dolomite formations, showing that vugs improve wormhole penetration distance. The model reproduced the outcomes from the literature, showing that the heat of reaction has a negligible effect on wormhole propagation. On the contrary, increasing the injected acid temperature reduced the wormhole radius in limestone but improved its efficiency in dolomite. The acid could not create efficient wormholes at low acid temperatures in dolomite formation. It diverted itself towards the limestone in sequence mineralogy cases. Nevertheless, it equally stimulated the limestone and dolomite sections at elevated acid temperatures. The reservoir temperature was less critical than the acid temperature in determining the wormhole size and treatment efficiency. The model can be used to select the optimum temperature at which the most efficient wormhole is created.