Equal Depth Research Articles

Experimental Study of Robotic Polishing Process for Complex Violin Surface

This paper presents a robotic polishing process for complex violin surfaces to increase efficiency and minimize the cost and consumed time caused by using labor and traditional polishing machines. The polishing process is implemented based on modeling a smooth path, controlled contact force embedded with gravity compensation and material removal depth. A cubic Non-Uniform Rational Bases-Spline (NURBS) interpolation curve combined with an S-curve trajectory model is used to generate a smooth polishing path on a complex violin surface to achieve stable motion during the polishing process. An online admittance controller added to the fast gravity compensation algorithm maintains an accurate polishing force for equal removal depth on all polished surface areas. Then, based on Pythagorean theory, the removal depth model is calculated for the violin’s complex surface before and after polishing to estimate the accuracy of the polishing process. Experimental studies were conducted by polishing a wooden surface using the 6DOF robot manipulator to validate this methodology. The experimental results demonstrated that the robot had accurate polishing force based on the online admittance controller with gravity compensation. It also showed a precise proportional uniformity of removal depths at the different normal forces of 10, 15, and 20 N. The final results indicated that the proposed experimental polishing approach is accurate and polishes complex surfaces effectively.

Aerification Strategies Affecting Golf Green Subsurface Properties

Golf greens often become compacted due to: 1. Construction of less-than-ideal soil containing high percentages of silt and clay. 2. Extensive traffic not only from daily play but continuous maintenance often with heavy machinery. 3. Traffic not being sufficiently curtailed during periods of excessive soil moisture. A two-year field experiment was conducted on a 14-year-old U.S. Golf Association (USGA)-specified Crenshaw creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.)] research putting green in Clemson, SC, to evaluate the effects of varying spring HTA size and timing on turfgrass rooting, soil organic matter (OM) and soil properties. Spring HTA treatments included 1.2-cm i.d. tines spaced at 5.1 cm x 5.1 cm in March and May (standard); 1.2-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March only (2x); 0.9-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March and May; and 0.6-cm i.d. tines spaced at 3.8 cm x 3.4 cm in March, April, May and June. All aerification was to a depth of 7.6 cm, with cores removed. Plots aerified with 0.6-cm tines had the least 2-year reduction in dry root weight (DRW). Plots aerified with 1.2-cm tines in March only (2x) had the greatest reduction in DRW and had the deepest thatch mat depth (TMD) across both years. This “doubling up” treatment would not be advisable on greens where low root mass or thatch accumulation is a concern. Plots aerified with 1.2-cm tines had higher thatch OM content in Year 2. Plots aerified with 0.6-cm tines had higher soil OM content across both years. Repetitive equal depth aerification did not create a layer of increased compaction. Turf managers can vary their spring HTA size and timing to increase TQ during periods where this is important (e.g., for a tournament) with manageable effects on surface, OM, and soil properties.

On reaction-diffusion models with memory and mean curvature-type diffusion

We propose and study a reaction-diffusion model with memory, where the linear diffusion operator is replaced by the mean curvature operator both in Euclidean and Lorentz–Minkowski spaces and the memory kernel is assumed to be of Jeffreys type. Regarding the reaction term, we consider a balanced bistable function f=−F′, with F a generic double well potential with wells of equal depth. In particular, we assume that the potential F has two global minima at ±1 and that F(u)∼|1±u|2+θ, for some θ>−1, when u≈±1, and we consider the corresponding equation in a bounded interval with homogeneous Neumann boundary conditions. We prove that if θ∈(−1,0), then there exist special steady states, named compactons, with a transition layer structure. In contrast, if θ≥0 the interface layers are not stationary and two different phenomena emerge: for θ=0 solutions exhibit a metastable behavior and maintain an unstable structure for an exponentially long time, while if θ>0 the exponentially slow motion is replaced by an algebraic one.

The research on the treatment effects of nano Berberine gel on superficial burn thickness

Objectives: To evaluate the analgesic effect of nano Berberin gel in the treatment of superficial burns.Subjective and Method: Study on 32 pediatric burn patients, treated at the Pediatric Burn Department in Le Huu Trac National Burn Hospital from 1 January 2022 to 30 April 2022. The method of study is a Prospective study, a randomized controlled trial. with comparison before-after. In the same patient, the burn was divided into 2 areas of equal area and depth. Study area: burns treated with a gel containing nano Berberine and comparison area: burns treated with 1% SSD cream. Results: 1. Having an anti-inflammatory effect: Reduction of the degree and duration of inflammation and reduced significantly the exudation on the study burn wound compared to the control area. 2. Nano Berberin gel dries wet necrosis (obvious after 2 - 3 days of using the drug). 3. Gel has the effect of preventing infection. A significant reduction in the number of positive cultures and the number of bacteria after 1 - 2 weeks of treatment, (78.33 ± 46.69 vs 105.16 ± 91.28 p < 0.05). The number of infected wounds after 1 week also decreased significantly in the control area, (25% vs 61.5% in zone A; 33.3% vs 58.3% in zone B) p<0.05. 4. The time for 50% epithelialization, the treatment time in the study area is also shorter than in the control area, (6.9 ± 3.6 vs 8.1 ± 4.2; p < 0.05). Conclusion: Initial remarkable recognition of the treatment effect of Nano Berberin Gel on the pediatric superficial burn.

Peat Soil Compaction Characteristic and Physicochemical Changes Treated with Eco-Processed Pozzolan (EPP)

Peat soil was defined as the highly organic surface layer derived primarily from plant remains. Peat, on the other hand, was the subsurface of wetland systems, consisting of unconsolidated superficial layers with a high non-crystalline colloid (humus) content. Peat soils have a low shear strength of 5 to 20 kPa, a high compressibility of 0.9 to 1.5, and a high moisture content of >100%. The purpose of the study was to prognosticate the potential of Eco-Processed Pozzolan (EPP) as peat soil stabilization material with improved technique and its consequence of the methods, which was the peat soils index properties and analyse the characteristics of the peat soil stabilization before and after treatment using Eco-Processed Pozzolan (EPP). The soil was mixed with 10, 20, and 30% Eco-Processed Pozzolan (EPP) and then compacted (compaction test) in a metal mould with an internal diameter of 105 mm using a 2.5 kg rammer of 50 mm diameter, freefalling from 300 mm above the top of the soil Three layers compaction of approximately equal depth and 27 blows spread evenly over the soil surface for each layer. The expected result to accomplish the main purpose was to prognosticate the potential Eco-Processed Pozzolan (EPP) as peat soil stabilization material with improved technique and its consequence of the methods. According to the findings, peat soil treated with EPP will transform its qualities from peat to usable soil. However, the presence of moisture will reduce the mixture's ability. According to the findings of this study, the optimum EPP for stabilizing peat soils was 30-40%. Correspondingly, the elemental composition of peat soil mixed with EPP improved regardless of Carbon, Ca composition. Comparatively, the amount of Silicon, Si increased from 6.5% (Peat + EPP 10%) to 12.9% (Peat + EPP 40%) due to the crystallization of EPP and peat. Doi: 10.28991/CEJ-2023-09-01-07 Full Text: PDF

Technical note: Determining equivalent squares of high-energetic photon fields.

We developed a method based on a physical pencil beam model for accurate equivalent square calculations for rectangular and irregular fields, for different definitions of equivalent squares, for beams with and without flattening filter, different photon energies, and depths in water. We considered two equivalent square definitions: equal dose at a point on the beam axis and equal depth dose, measured as tissue phantom ratio at 20 and 10cm depth ( ). As dose engine, we used an analytical pencil beam model. By integrating the pencil beam kernels, we assigned square fields to rectangular fields minimizing the dose, respectively, the difference. The results were compared with measurements at 100mm depth for nominal beam energies of 6 and 18MV, the Sterling equation, the geometric mean, and data from BJR Suppl 25 (British Institute of Radiology, 1996). Pencil beam results were closest to the measurements. An energy dependence of several millimeters for small field dimensions and depth dependencies for very elongated fields were observed. For the assignment of WFF square to FFF rectangular fields, using the equal- definition, our method agrees with previously published results. For circular fields approximated by leaves, we found deviations to the data from BJR Suppl. 25 below 1mm for diameters smaller than200mm. Our study shows that the validity range for geometric mean and Sterling equationis limited. Ergo, instead of specifying specific validity ranges, we suggest using the pencil beam method, valid for all aspect ratios, including elongated fields in the primary dose dominated regime. We published our method as python library and graphical user interface on GitHub. Users can choose between two definitions of equivalent square and between WFF and FFF fields. The implemented pencil beam method for irregular fields is also usable for quality assurance such as monitor unitchecks.

Notch Effects on the Stress Intensity Factor and on the Fatigue Crack Path for Eccentric Circular Internal Cracks in Elliptically Notched Round Bars under Tensile Loading.

In this paper, stress intensity factor (SIF) solutions are numerically obtained for notched bars subjected to tensile loading containing an eccentric circular inner crack located in the cross-section corresponding to the notch root. The finite element method and the J-integral have been used to obtain the SIF and to analyze the effect on it of three elliptical notch geometries (of equal radial depth). The results show how the SIF is greater in the notched bars than in the smooth bar and within the former when the axial semi-axis of the notch rises, its effect being greater as the diameter and eccentricity of the inner crack increase. In addition, the fatigue growth of an eccentric crack induces an increase in such eccentricity, greater as the notch axial semi-axis increases. The cause of these phenomena can be attributed to the constraint loss caused by the notch, which also facilitates bending of the specimen due to the asymmetry generated by the crack eccentricity.

On Mechanical and Motion Behavior of the Normal Impact Interface between a Rigid Sphere and Elastic Half-Space

This paper presents exact solutions for the mechanical behavior of the interface during the normal collision between a rigid sphere and an elastic half-space based on kinematics and particle dynamics theory. The interfacial contact stress is significantly different from the static solution obtained from the Hertz contact theory. Firstly, according to the kinematics theory, the elastic half-space interface deformation of the sphere and the half-space interface in the collision process is divided into the deformation of the contact area and the non-contact area. The curve of the non-contract area is strictly antisymmetric to the deformation curve of the contact area, and the lateral deformation for each particle at the interface can be neglected when the collision depth is relatively small. Then, the vertical deformation equation of the contact area of the half-space interface, the dynamic equation of the rigid sphere, and the dynamic equation of the interface particle in the contact region are established. The proportional relationship between the stress or strain of any particle in the contact area, the stress or strain of the collision center point, and the method for determining the maximum collision depth are obtained. The equal deformation depth in the contact and non-contact regions, and the proportional relationship between the stress or strain in the contact area and the center point of the collision at any moment are consistent with the Hertz contact theory, which verifies the reliability of the current study. Taking the sphere of no initial velocity collides with the half-space under pure gravity as an example, when the elastic half-space Poisson’s ratio is taken as 0.2–0.4, the ratio of the maximum contact stress determined by the Hertz theory and the current solution when the sphere reaches the maximum collision depth is 0.58–0.54. Based on this study, the contact stress and its distribution in the interfacial contact region can be obtained when the motion state of the sphere and the interface are determined.

Metaphysical Emergence

<i>Metaphysical Emergence</i>

Systematic Metamodel-Based Optimization Study of Synchronous Reluctance Machine Rotor Barrier Topologies

Nowadays, due to the confidence in modeling tools and rapid product iteration, electric machine designers primarily rely on simulations. This approach reduces time and cost and is very useful when comparing different machine topologies. The prototype stage usually comes after the depletion of all simulation resources. When designing a synchronous reluctance machine, the first step is the selection of rotor barrier type. The literature provides several topologies but does not clearly state which one yields the best performance. The goal of this paper is to determine the best variant for a six-pole machine and the selected requirements using a metamodel-based optimization approach. Seven rotor topologies with different complexities were derived from circular, hyperbolic, and Zhukovsky barrier types (circular concentric, circular variable depth, hyperbolic with fixed eccentricity, hyperbolic with variable eccentricity, original Zhukovsky, modified Zhukovsky variable depth and modified Zhukovsky with equal barrier depth). The novelty of the proposed strategy is in the systematic and fair comparison of different rotor topologies. This approach significantly reduces the total optimization time from several weeks to a few days. Additionally, a novel modified Zhukovsky variable depth topology, which merges the best qualities of all considered variants, was developed. An identical optimization strategy was applied to all variants, and the final results prove that the barrier type substantially affects the final performance of the machine. The best results are achieved by the modified Zhukovsky variable depth topology. In relation to the worst (baseline) topology, the performance gain is 14.9% and the power factor is increased from 0.61 to 0.67. An additional study using different numbers of barrier layers (3, 4, and 5) was conducted to determine the best topology. The best results were achieved with the original four barrier layers.

Metagenomics versus total RNA sequencing: most accurate data-processing tools, microbial identification accuracy and perspectives for ecological assessments.

Metagenomics and total RNA sequencing (total RNA-Seq) have the potential to improve the taxonomic identification of diverse microbial communities, which could allow for the incorporation of microbes into routine ecological assessments. However, these target-PCR-free techniques require more testing and optimization. In this study, we processed metagenomics and total RNA-Seq data from a commercially available microbial mock community using 672 data-processing workflows, identified the most accurate data-processing tools, and compared their microbial identification accuracy at equal and increasing sequencing depths. The accuracy of data-processing tools substantially varied among replicates. Total RNA-Seq was more accurate than metagenomics at equal sequencing depths and even at sequencing depths almost one order of magnitude lower than those of metagenomics. We show that while data-processing tools require further exploration, total RNA-Seq might be a favorable alternative to metagenomics for target-PCR-free taxonomic identifications of microbial communities and might enable a substantial reduction in sequencing costs while maintaining accuracy. This could be particularly an advantage for routine ecological assessments, which require cost-effective yet accurate methods, and might allow for the incorporation of microbes into ecological assessments.

Effect of depth discontinuity on interfacial stability of tangential-velocity discontinuity in shallow-water flow

It is well known that an interface of tangential velocity discontinuity is necessarily unstable, regardless of the velocity difference's strength, so-called the Kelvin-Helmholtz instability (KHI). However, the instability is suppressed for shallow water flows if the Froude number, defined by the ratio of the velocity difference to the gravity wave's speed, is sufficiently large. In this investigation, we examine the effect of the depth difference of two fluid layers on the KHI. The depth difference enhances instability. The dispersion equation is obtained in a sextic polynomial, the interface is thus linearly stable if the dispersion equation has enough six real roots. Given the Froude number M1 in the instability range, the growth rate sensitively depends on the depth ratio r=H1/H2 and increases monotonically with the depth ratio difference from unity. The critical value of the Froude number for stabilization varies with the depth ratio and attains the minimum value 8 for equal depth. This behavior is verified by asymptotic and numerical analysis. Numerically, we illustrate that if the depth ratio r=0.5, the Froude number is equal or greater than 33≈5.745 to stabilize the interface and it is 4.08 for r=2.

A two-step identification method for crack parameter identification of train axles

Abstract In this paper, a crack parameter identification method based on the coordinate of 1x intersections and Kriging surrogate model with enhanced samples is proposed to solve the crack parameter identification problem of train axles in start-stop condition. The location of the crack is identified in the first step by the x-coordinate of the linear intersection of 1x frequency components. Then, the intersecting coordinates and rigid constraint points were used to solve response curves of equal crack depth, and numerous enhanced samples of same depth at different positions were obtained to establish a Kriging model. Finally, the crack depth was directly obtained by the Kriging model. In this paper, response curve s of equal crack depth is proposed according to the symmetry of the train structure, which greatly reduces the number of samples needed to construct the Kriging model. Numerical simulation and experimental results demonstrate the effectiveness and robustness of the proposed method.

Sequencing Depth Has a Stronger Effect than DNA Extraction on Soil Bacterial Richness Discovery.

Although Next-Generation Sequencing techniques have increased our access to the soil microbiome, each step of soil metagenomics presents inherent biases that prevent the accurate definition of the soil microbiome and its ecosystem function. In this study, we compared the effects of DNA extraction and sequencing depth on bacterial richness discovery from two soil samples. Four DNA extraction methods were used, and sequencing duplicates were generated for each DNA sample. The V3–V4 region of the 16S rRNA gene was sequenced to determine the taxonomical richness measured by each method at the amplicon sequence variant (ASV) level. Both the overall functional richness and antibiotic resistance gene (ARG) richness were evaluated by metagenomics sequencing. Despite variable DNA extraction methods, sequencing depth had a greater influence on bacterial richness discovery at both the taxonomical and functional levels. Sequencing duplicates from the same sample provided access to different portions of bacterial richness, and this was related to differences in the sequencing depth. Thus, the sequencing depth introduced biases in the comparison of DNA extraction methods. An optimisation of the soil metagenomics workflow is needed in order to sequence at a sufficient and equal depth. This would improve the accuracy of metagenomic comparisons and soil microbiome profiles.

Energy and entropy compensation, phase transition and kinetics of four dimensional charged Gauss-Bonnet Anti-de Sitter black holes on the underlying free energy landscape

By treating black hole as a state in canonical ensemble or in grand canonical ensemble, we study the phase transition and the kinetics of the four dimensional charged Anti-de Sitter (AdS) black hole in Gauss-Bonnet (GB) gravity based on the free energy landscape. Below the critical temperature, the free energy landscape topography has the shape of double basins with each representing one stable/unstable black hole phase (the small or the large black hole). The thermodynamic small/large black hole phase transition is determined by the equal depths of the basins. We also demonstrate the underlying kinetics of the phase transition by studying the time evolution of the probability distribution of the state in the ensemble as well as the mean first passage time (MFPT) and the kinetic fluctuations of the state switching process caused by the thermal fluctuations. The results show that the final distribution is determined by the Boltzmann law and the MFPT and its fluctuation are closely related to the free energy landscape topography through the barrier heights between the small and the large black hole states and the ensemble temperature. Furthermore, we provide a complete description of the kinetics of phase transition by investigating the temperature dependence of the MFPT and the kinetic fluctuations with different physical parameters. It is shown that the free energy is the result of the delicate balance and competition between the two relatively large numbers, the energy and entropy multiplied by temperature compared to kT. Low energy (mass) and low entropy can give rise to a stable thermodynamic state in terms of free energy minimum (energy/mass preferred) while the high energy (mass) and high entropy (entropy preferred) can also give rise to a stable state in terms of free energy minimum. The comparable free energy barrier with respect to kT makes it possible for the switching from small size black hole state to the large size black hole state under thermal fluctuations and vice versa. When the GB coupling coupling constant increases, or the electric charge (potential) increases, or the pressure (absolute value of cosmological constant) decreases, it is easier for the small black hole state to escape to the large black hole state. Meanwhile, the inverse process becomes harder, i.e. the small (large) black hole state becomes less (more) stable.

The Non-Equivalence of Pyramids and Their Pseudo-Cones: Important New Insights

The simulation of indentations with so called “equivalent” pseudo-cones for decreasing computer time is challenged. The mimicry of pseudo-cones having equal basal surface and depth with pyramidal indenters is excluded by basic arithmetic and trigonometric calculations. The commonly accepted angles of so called “equivalent” pseudo-cones must not also claim equal depth. Such bias (answers put into the questions to be solved) in the historical values of the generally used half-opening angles of pseudo-cones is revealed. It falsifies all simulations or conclusions on that basis. The enormous errors in the resulting hardness HISO and elastic modulus Er-ISO values are disastrous not only for the artificial intelligence. The straightforward deduction for possibly ψ-cones (ψ for pseudo) without biased depths’ errors for equal basal surface and equal volume is reported. These ψ-cones would of course penetrate much more deeply than the three-sided Berkovich and cube corner pyramids (r a/2), and their half-opening angles would be smaller than those of the respective pyramids (reverse with r > a/2 for four-sided Vickers). Also the unlike forces’ direction angles are reported for the more sideward and the resulting downward directions. They are reflected by the diameter of the parallelograms with length and off-angle from the vertical axis. Experimental loading curves before and after the phase-transition onsets are indispensable. Mimicry of ψ-cones and pyramids is also quantitatively excluded. All simulations on their bases would also be dangerously invalid for industrial and solid pharmaceutical materials.

Biological resources of water bodies in the Volga region, formed by water retaining structures as exemplified by the Gorodskoye water reservoir in Penza region

Along with classic reservoirs and ponds located on middle and small streams of the Volga region, there is a large number of partially regulated river channels formed by water retaining structures and other artificial obstacles, which differ significantly from natural channels by morphometric and hydrological parameters, which allows to classify them into a separate type of water bodies - channel-type water reservoirs. The article considers the condition of aquatic bioresources in such reservoirs on the example of the largest in the Penza region - “Gorodskoye” on the river Sura in comparison with the classic reservoir Surskoye (Penzenskoye) (on the river Sura) and the natural riverbed itself. The analysis of fish production by food components showed that with equal depth per hectare the highest fish production by “soft” zoobenthos, mollusks, zooplankton is observed in the Gorodskoye reservoir, by phytoplankton - in the Surskoye reservoir. Taking into account the average depth of reservoirs, where the Gorodskoye reservoir is in the middle position, it is not much inferior to the Surskoye reservoir in terms of fish food production. Ichthyomass of fishery stock of the Gorodskoye reservoir is three times higher than that of the Sura river channel and 25% lower than that of the Surskoye reservoir with its large fattening areas and depths. Accordingly, the channel impoundments are close to classic reservoirs in terms of aquatic bioresources status and therefore cannot be considered alongside natural river channels. They require a separate study, use and special fishery status. Accounting for aquatic bioresources in such reservoirs and carrying out reproductive measures makes it possible to significantly increase catch quotas for commercial fish species in such low-water regions as Penza region.

Richness estimation in microbiome data obtained from denoising pipelines

The quantification of richness within a sample—either measured as the number of observed species or approximated by estimation—is a common first step in microbiome studies and is known to be highly dependent on sequencing depth, which itself is highly variable between samples. Rarefaction curves serve as a tool to investigate this dependency and it is often argued that after rarefying data—sub-sampling to an equal sequencing depth—richness estimates no longer depend on sequencing depth. However, the estimation of richness from data obtained by high throughput sequencing methods and processed by current bioinformatics pipelines may be subject to various sources of variation related to sequencing depth. Those that may confound inference based on richness estimates and cannot be solved by sub-sampling. We investigated how pipeline settings in DADA2 and deblur affect estimates of richness and showed that the use of rarefaction and sub-sampling is inappropriate when default pipeline settings are applied. Furthermore, we showed how independent sample-wise processing established spurious correlations between sequencing depth and richness estimations in data produced by DADA2 and how this problem can be solved by a pooled processing approach.

Impact of inclined double-cutoff walls under hydraulic structures on uplift forces, seepage discharge and exit hydraulic gradient

In hydraulic structures design, using cutoff walls is essential to reduce and control the resultant uplift force (U), seepage discharge (Q), and exit hydraulic gradient (i). This research investigates the effectiveness of inclined double cutoff walls under hydraulic structures, considering the influence of depths, locations, and inclination angles of the upstream and downstream cutoff walls by using Finite Element Method (FEM). The results confirmed that installing a deeper cutoff wall on the downstream reduces the exit gradient even further. In the case of the cutoff walls located in the upstream and downstream ends, the exit gradient will be less than when the cutoff walls are installed at a closer distance. Increasing the inclination angle of downstream cutoff wall has a major impact on exit gradient reduction. Embedment of cutoff walls in the upstream and downstream ends with right angles and equal depths reduces the seepage discharge more than other cases.

Experimental Study on the Behavior of Header End - Plate Connections under Cyclic Loading

This paper presents the results from experimental study on the actual behavior of header end-plate connections. To better understand the hysteretic behavior of these connections in terms of the stiffness and the strength, sixteen specimens were considered and subjected to cyclic loads. The effect of some parameters such as thickness of the header end-plate, depth of the connection and the number of bolt rows on the behavior of header end-plate connections has been investigated by the help of experimental tests and finite element (FE) analyses. The moment-rotation relations of the connections governed by three parameters such as, initial stiffness, moment capacity and rotation capacity were obtained. Results revealed that the moment capacity increases with the increase in end-plate thickness and depth of connection. However, for the equal connection depth, increasing the number of bolt rows has not influenced the connection behavior remarkably.