Points Of Curve Research Articles

Analysis of wheel-rail adhesion redundancy considering the third-body medium on the rail surface

PurposeIn response to the problem of insufficient traction/braking adhesion force caused by the existence of the third-body medium on the rail surface, this study aims to analyze the utilization of wheel-rail adhesion coefficient under different medium conditions and propose relevant measures for reasonable and optimized utilization of adhesion to ensure the traction/braking performance and operation safety of trains.Design/methodology/approachBased on the PLS-160 wheel-rail adhesion simulation test rig, the study investigates the variation patterns of maximum utilized adhesion characteristics on the rail surface under different conditions of small creepage and large slip. Through statistical analysis of multiple sets of experimental data, the statistical distribution patterns of maximum utilized adhesion on the rail surface are obtained, and a method for analyzing wheel-rail adhesion redundancy based on normal distribution is proposed. The study analyzes the utilization of traction/braking adhesion, as well as adhesion redundancy, for different medium under small creepage and large slip conditions. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived.FindingsWhen the third-body medium exists on the rail surface, the train should adopt the low-level service braking to avoid the braking skidding by extending the braking distance. Compared with the current adhesion control strategy of small creepage, adopting appropriate strategies to control the train’s adhesion coefficient near the second peak point of the adhesion coefficient-slip ratio curve in large slip can effectively improve the traction/braking adhesion redundancy and the upper limit of adhesion utilization, thereby ensuring the traction/braking performance and operation safety of the train.Originality/valueMost existing studies focus on the wheel-rail adhesion coefficient values and variation patterns under different medium conditions, without considering whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train. Therefore, there is a risk of traction overspeeding/braking skidding. This study analyzes whether the rail surface with different medium can provide sufficient traction/braking utilized adhesion coefficient for the train and whether there is redundancy. Based on these findings, relevant measures for the reasonable and optimized utilization of adhesion are derived to further ensure operation safety of the train.

Experimental study on stress-strain relationship of high strength coral concrete (HSCC)

In recent decades, with the advancement of coral reef construction, the inception of design and production of coral concrete has emerged. However, current research primarily focuses on medium and low strength grades, leaving the exploration of high-strength coral concrete (HSCC) in its infancy. Therefore, in this paper, uniaxial compression test and microscopic mean are utilized to investigate the stress-strain full curves, crack development and damage characteristics of HSCC with different strength grades and fiber. The findings demonstrate that after the peak stress, the stress of HSCC with different strength grades decreases sharply, and their residual stresses are 21.5%–30.3% of the peak stress, which is lower than that of ordinary coral concrete, which is 29.2%–52.5%. The crack inclination angle θ of high-strength coral concrete containing fiber is mainly concentrated at 62°–70°, and it shows ductile damage. Moreover, fiber in high-strength coral concrete undergoes damage mainly by pulling and breaking. Additionally, the locations of the characteristic points of the stress-strain curves of HSCC are significantly different from those of ordinary concrete and lightweight aggregate concrete, and the constitutive equation proposed in the paper effectively reflect the variation of the stress-strain curves of HSCC.

An improved analysis of small punch deformation for evaluating tensile properties

Small punch (SP) method is a promising technique for evaluating tensile properties using small volumes of test material, yet its applicability is bound by large errors in estimation of tensile yield strength (YS) using the yield force (FY) determined by the existing two tangent, offset or bilinear function fitting methods. In this study, a yield force (FY) based on the occurrence of yielding across the specimen thickness is identified through finite element analysis and a methodology is formulated for determination of FY from experimental data, supported with acoustic emission (AE) technique. The YS-FY correlation for various structural steels, Inconel and Aluminium exhibit excellent linearity and standard errors within ±7 %. Based on the onset of plastic instability in SP deformation at an inflection point (Fs, us) of force-deflection curve, the specimen deflection us is shown to correlate with tensile uniform strain better than parameter um (deflection at peak load). The tensile properties of neutron irradiated SS 316 evaluated from SP tests using the methodologies and SP-tensile correlations formulated in this work, are found to be within 6–8 % of the uniaxial tensile test results.

Usefulness of TyG-index to determines insulin resistance in obese adolescents

Background: Obesity is associated with Insulin Resistance (IR). The Triglycerides Glucose (TyG) index have been used to assess IR, however it needs to establish cut-off points to use in the obese adolescence. Purpose: This study aims to analyse the TyG-index as marker of IR in obese adolescence. Methods: A cross sectional study was conducted on obese adolescents aged 13-18 years in secondary school. Anthropometric measurements were performed. Lipid profile, fasting blood glucose, and insulin level were measured. HOMA IR were calculated using the formula: [glucose (mg/dL) x Insulin (µu/L)] / 405, cut-off value to describes IR was > 3.43 for both sexes which performs for pediatric population. TyG-index was calculated by the formula: TyG = Ln [TG (mg/dl) × FBG (mg/dl)]/2. Receiving operation characteristic (ROC) were carried out to determines area under curve (AUC) and cut-off points of IR for TyG-index determines by the biggest value of Youden index. Results: A total of 256 adolescents with obesity were participated this study. 59.8% (153/256 or) were non-IR, while 40.2% (103/256) had IR; Male: female ratio was 144/112. TyG-index was higher significantly in subjects with IR than non-IR (4.63 + 0.25 vs 4.46 + 0.26; p<0.05). HOMA-IR correlated positively with TyG-index (r=0.397, p=0.000). AUC for TyG-index was 0.703, p=0.000 (95% CI [0.639-0.770]). The best cut-off points for TyG-index to determines IR >4.50, with sensitivity of 70.3% and specificity of 63.23%. Conclusion: TyG-index is useful to be an alternative marker for assessing IR in obese adolescence with the best cut-off point to distinguish IR is > 4.50.

Damage evolution analysis of concrete based on multi-feature acoustic emission and Gaussian mixture model clustering

In this work, a novel method for damage evolution analysis of concrete under uniaxial compression is proposed based on the multi-feature acoustic emission (AE) and the Gaussian mixture model (GMM) clustering. The hierarchical clustering algorithm is adopted to select optimal AE parameters, while multiple features of these parameters are generated through the principal component analysis (PCA). Then the concrete damage signals are separated by using the GMM clustering with multiple features. Meanwhile, the waveform signals associated with concrete damage in each cluster are validated using the Fast Fourier transform (FFT) and the continuous wavelet transform (CWT). Finally, the damage evolution process of concrete under uniaxial compression is divided based on the variation of AE characteristics. The results show that the frequency ranges of signals for micro-cracks, mixed cracks and friction of concrete under uniaxial compression are 20–30 kHz, 20–65 kHz, and 100–120 kHz, respectively. The damage process of concrete under uniaxial compression is divided into three stages according to the inflection points of the cumulative energy curve, namely the initial compaction stage, the crack formation stage and the failure stage.

Shape Recognition and Corner Points Detection in 2D Drawings Using a Machine Learning Long Short-Term Memory (LSTM) Approach

Creating a 2D geometry model from an image poses challenges for CAD users due to factors such as noise, segmentation difficulties, complex geometric structures, scale and perspective variations, and the need for CAD system compatibility. In this paper, we propose a novel deep learning approach utilizing Long-Short Term Memory (LSTM) to address these challenges. Our approach decomposes the shapes in the images into line and curve segments and accurately locates their intersection points. To enhance the model’s performance, we introduce two distinct types of features (angle and curvature features) and optimize the model through hyperparameter tuning. The resulting model exhibits robustness against noise, varying image sizes, and can effectively locate different types of intersection points. To evaluate the proposed model, we have developed a Python-based software and conducted experiments on a dataset comprising of 200 shapes with seven different resolutions. Comparative analysis against a state-of-the- art method (TCVD) from the literature demonstrates that our approach achieves higher accuracy in terms of line, curve, and intersection point detection.

A fault diagnosis method of battery internal short circuit based on multi-feature recognition

The internal short circuit (ISC) fault has been considered as one of the most serious problems, which may pose a threat to the operation safety of the battery system. To solve this problem, this paper proposes an ISC fault diagnosis method based on multi-feature recognition to distinguish aging and ISC fault. The ISC equivalent circuit model is established first. In addition, three characteristic parameters, including the slope of the “rebound” voltage curve, the “valley” ordinate in the differential voltage (DV) curve, and the electric quantity, namely high segment charging capacity (HSCC) between the valley point of the DV curve and the end of charging position, are extracted to distinguish the ISC battery from aging battery. The results show that the proposed method can effectively distinguish between ISC batteries, aging batteries, and normal batteries. Moreover, the ISC resistance is able to be estimated accurately, with an error of less than 5.44%.

Numerical analyses of M31 dark matter profiles

In this paper, we reproduce the rotation curve of the Andromeda galaxy (M31) by taking into account its bulge, disk and halo components, considering the last one to contain the major part of dark matter mass. Hence, our prescription is to split the galactic bulge into two components, namely, the inner and main bulges, respectively. Both bulges are thus modeled by exponential density profiles since we underline that the widely accepted de Vaucouleurs law fails to reproduce the whole galactic bulge rotation curve. In addition, we adopt various well-known phenomenological dark matter profiles to estimate the dark matter mass in the halo region. Moreover, we apply the least-squares fitting method to determine from the rotation curve the model free parameters, namely, the characteristic (central) density, scale radius and consequently the total mass. To do so, we perform Markov chain Monte Carlo statistical analyses based on the Metropolis algorithm, maximizing our likelihoods adopting velocity and radii data points of the rotation curves. We do not fit separately the components for bulges, disk and halo, but we perform an overall fit including all the components and employing all the data points. Thus, we critically analyze our corresponding findings and, in particular, we employ the Bayesian information criterion to assess the most accredited model to describe M31 dark matter dynamics.

Quality monitoring for a resistance spot weld process of galvanized dual-phase steel based on the electrode displacement

In previous works, it has been found out that the electrode displacement in resistance spot welding has a high potential to be used as a measurement factor to monitor joint quality and to subsequently optimize the welding parameters. By extracting characteristic points in the displacement curve, it is possible to create and evaluate different parameter sets and to predict the formation of expulsion. These characteristic points include for example the maximum displacement of the electrodes, the time of the maximum displacement, the indentation displacement in the weld and hold time, or the velocity of the electrodes. In previous work, it was already shown that the indentation displacement showed satisfying results in predicting the nugget diameter for a press hardened 22MnB5 + AS150 under laboratory conditions. Based on that, a newly derived methodology for using the electrode displacement in monitoring a resistance spot weld process is shown for a galvanized dual-phase steel CR440Y780T-DP GI50/50-U. This methodology combines the knowledge of previous research and is split into three steps: the detection of manufacturing discontinuities, the evaluation of expulsion, and the monitoring of the nugget diameter. For this, the electrode velocity at the beginning of the process and the indentation displacements in the weld and hold time are being used to evaluate the resistance spot welding process.

Hydrocephalus following Brain Tumor Surgery: Factors Correlating with Occurrence of Postoperative Hydrocephalus and Predictive Scoring Model.

Hydrocephalus following brain tumor surgery is found, although cause of hydrocephalus is optimally eradicated. This study aimed to investigate factors associated with development of postoperative hydrocephalus that requires shunt procedure and generate predictive scoring model of this condition. Demographic, clinical, radiographic, treatment, laboratory, complication, and postoperative data were collected. Binary logistic regression was used to investigate final model for generating predictive scoring system of postoperative hydrocephalus. A total of 179 patients undergoing brain tumor surgery were included. Forty-five (25.1%) patients had postoperative hydrocephalus that required shunt surgery. In univariate analysis, several factors were found to be associated with postoperative hydrocephalus. Strong predictors of postoperative hydrocephalus revealed in multivariate analysis included tumor recurrence before surgery (odds ratio [OR], 4.38; 95% confidence interval [CI], 1.28-14.98; p = 0.018), preoperative hydrocephalus (OR, 6.52; 95% CI, 2.44-17.46; p < 0.001), glial tumor (OR, 3.76; 95% CI, 1.14-12.43; p = 0.030), metastasis (OR, 5.19; 95% CI, 1.72-15.69; p = 0.004), intraventricular hemorrhage (OR, 7.08; 95% CI, 1.80-27.82; p = 0.005), and residual tumor volume (OR, 1.05; 95% CI, 1.01-1.09; p = 0.007). A cutoff predictive score with the best area under curve and optimum cutoff point was utilized for discriminating patients with high risk from individuals with low risk in occurrence of postoperative hydrocephalus. This study reported predictive factors strongly associated with development of postoperative hydrocephalus. Predictive scoring system is useful for identifying patients with an increased risk of postoperative hydrocephalus. Patients classified in the high-risk group require closed surveillance of the hydrocephalus.

An improved complexity bound for computing the topology of a real algebraic space curve

We propose a new algorithm to compute the topology of a real algebraic space curve. The novelties of this algorithm are a new technique to achieve the lifting step which recovers points of the space curve in each plane fiber from several projections and a weaker notion of generic position. As distinct to previous work, our sweep generic position does not require that x-critical points have different x-coordinates. The complexity of achieving this sweep generic position property is thus no longer a bottleneck in term of complexity. The bit complexity of our algorithm is O˜(d18+d17τ) where d and τ bound the degree and the bitsize of the integer coefficients, respectively, of the defining polynomials of the curve and polylogarithmic factors are ignored. To the best of our knowledge, this improves upon the best currently known results at least by a factor of d2.

Prospective learning curve analysis of en bloc resection of bladder tumor using an ex vivo porcine model

BackgroundAs a relatively new surgical technique, the learning curve of en bloc resection of bladder tumor (ERBT) in ex vivo models remains unaddressed. This study aimed to explore the learning curve of ERBT in an ex vivo porcine model.MethodsIn this prospective study, eight endoscopists without prior experience in ERBT were divided into two groups: junior endoscopists, with less than 100 transurethral resection of bladder tumor (TURBT) procedure experience, and senior endoscopists, with at least 100 TURBT procedure experience. Each endoscopist performed 30 ERBT procedures on artificial lesions in an ex vivo porcine bladder model. The procedure time, perforation, en bloc resection status, and absence of detrusor muscle (DM) were recorded. The inflection points were identified using cumulative sum (CUSUM) analysis. Procedure results were compared between the two phases and two groups.ResultsIn all, 240 artificial lesions were successfully resected using ERBT. The CUSUM regression line indicated the inflection point at the 16th procedure for the junior endoscopists and at the 13th procedure for the senior endoscopists. In both groups, the procedure time, perforation, piecemeal resection, and DM absence rates were significantly lower in the consolidation phase than in the initial phase. The procedure time for the senior endoscopists was lower than for the junior endoscopists in both phases.ConclusionsERBT performance improved significantly after reaching the inflection point of the learning curve in the ex vivo model. We recommend a minimum of 16 ERBT procedures in ex vivo models for urologists with less than 100 TURBT experience and a minimum of 13 procedures for those with at least 100 TURBT experience before advancing to live animal training or supervised clinical practice.

Simplified methodology for fatigue analysis of reinforced asphalt systems

Fatigue analysis has an important role in evaluating the durability and performance of asphalt pavements, especially when novel or alternative materials are used. Numerous laboratory studies have investigated fatigue performance with the aim of estimating field behavior as accurately as feasible. Therefore, there are currently many different test methods and data analysis approaches that can be used. One of the most common laboratory test methods is the four-point bending beam (4PBB) test, which results are usually analyzed using the so-called traditional (where 50% reduction in initial stiffness is considered as failure criterion) or the energy ratio (ER) approach. However, outcomes from previous studies have shown that these approaches may not be appropriate and reliable if geogrids are used as a reinforcement. As a possible solution, this study proposes a new simplified flex point (SFP) approach that considers the flex point of the strain amplitude curve, measured during 4PBB fatigue tests, to calculate the number of cycles to failure. These three approaches were applied to four double-layered asphalt sets: one unreinforced and three reinforced with geogrids of different strength (50 x 50, 100 x 100 and 100 x 200 kN/m). The impact of reinforcement on the fatigue life was evaluated by comparing the critical strain values (ε6) of reinforced and unreinforced sets through the fatigue resistance improvement factor. The research findings showed that the use of geogrids improves fatigue life when the SFP and ER approaches are applied and that the traditional approach might not always be appropriate for assessing the fatigue resistance of reinforced asphalt mixtures.

The effect of tessellation on stiffness in the hyoid arch of elasmobranchs.

Tessellated cartilage forms much of the skeleton of sharks and rays, in contrast to most other aquatic vertebrates who possess a skeleton of bone. Interestingly, many species of sharks and rays also regularly generate exceptionally high forces in the execution of day-to-day activities, such as when feeding on bony fish, mammals, and hard-shelled invertebrates. Tessellated cartilage differs from other types of cartilage in that they are covered by an outer layer of small mineralized tiles (tesserae) that are connected by fibrous connective tissue. Tesserae, therefore, are hypothesized to play a role in stiffening the cartilaginous skeleton for food capture and other activities that require the generation of high forces. In this study, the hyomandibula and ceratohyal cartilages, which support the jaw and throat regions of sharks and rays, were tested under compressive load in a material testing system to determine the contribution of tesserae to stiffness. Previous hypotheses suggest an abrupt upward shift in the slope of the stress-strain curve in tessellated materials due to collision of tesserae. Young's Modulus (E) was calculated and used to evaluate cartilage stiffness in a range of elasmobranch species. Our results revealed that there was an abrupt shift in Young's Modulus for elements loaded in compression. We postulate that this shift, characterized by an inflection point in the stress-strain curve, is the result of the tesserae approaching one another and compressing the intervening fibrous tissue, supporting the hypothesis that tesserae function to stiffen these cartilages under compressive loading regimes. Using published data for nontessellated cartilage for comparison, we show that this shift is, as expected, unique to tessellated cartilage.

(187) The SAPOC Technique: Slices Around Point of Maximal Curvature at Time of IPP placement in Severe Peyronie's Disease

Abstract Introduction Placement of an inflatable penile prosthesis (IPP) is indicated for patients with severe Peyronie's disease and erectile dysfunction (ED). Most cases involving plaque incision and graft placement are performed at the point of maximal curvature which result in a large defect that requires placement of a large graft while postoperative penile shortening remains a significant concern among patients. Objective To present a video of a novel modification of the multiple slit technique (MUST) for the treatment of severe PD and ED during IPP placement. This technique involves multiple relaxing incisions made around the point of maximal curvature (POMC) which minimizes the size or even the need of a graft while allowing for length restoration. Methods This technique involves elevation of the neurovascular bundle for dorsal or lateral curvatures along with elevation of the urethra for ventral curvatures. After the POMC is identified, 2 to 4 transverse relaxing incisions (slices) are made around the POMC approximately 1 to 1.5cm apart in order to minimize the size of the defect and hence the need or size of the graft. Each slice allows for maximal restoration of length. Results The SAPOC technique results in correction of curvature and length restoration. Conclusions The SAPOC technique at the time of IPP placement is a novel, safe and feasible technique for the management of complex PD and ED. This technique allows the surgeon to complete the procedure without graft placement in some occasions which theoretically will decrease operative time. It also provides for length restoration which will increase patient satisfaction. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Consultant for Boston Scientific and Coloplast.

(402) Peyronie's Disease Treatment- Active Vs. Stable Phase- Retrospective Review of Cases

Abstract Introduction Peyronie's disease (PD) may be treated with collagenase clostridium histolyticum (CCH) during the stable phase. However, the effectiveness and safety of this treatment during the active phase remain unclear. To address this, we investigated and compared the outcomes of patients receiving treatment in the active phase versus the stable phase of PD. Objective To assess the effectiveness and safety of CCH treatment in patients diagnosed with PD during the active phase. Methods A retrospective review was conducted on men who underwent at least one cycle of CCH injections for PD with a single fellowship-trained urologist between 2017 and 2023. Active PD was defined as occurring within one year from the onset of symptoms. The severity of penile curvature was measured at the point of maximal curvature and assessed at baseline and after each CCH cycle. In addition to the CCH treatment, patients were prescribed daily phosphodiesterase inhibitors (PDEi) and coenzyme-Q10 (CoQ-10). The treatment response was defined as any improvement in curvature from baseline to the final assessment. The characteristics and outcomes of patients were compared between those with active and stable PD. Results Of 107 patients who underwent CCH treatment, 75 were diagnosed with stable PD and 32 with active PD. There were no significant differences observed between the two groups in terms of age (58.1 vs. 57.9 years, p = 0.89), baseline curvature (58.4 vs. 60.5 degrees, p = 0.60), or the number of CCH cycles received (6.6 vs. 6.3 cycles, p = 0.57). Among the active PD patients, 26 (81.2%) experienced an improvement in curvature, which was comparable to the stable PD group (58 (77.3%), p = 0.85). There were no significant differences in the degree of curvature improvement (14.4 vs. 14.0 degrees, p = 0.91) or the percentage of improvement from baseline (22.67% vs. 24.05%, p = 0.86) between the active and stable PD patients. In the subset of patients who showed an improvement in curvature angle, there was no notable distinction in the percentage of improvement from baseline between the stable and active phases (37.4% vs 34.8%, p=0.63). Among the treated patients, we observed two cases of potential penile fractures in the stable phase. All adverse events were conservatively managed. Conclusions Patients treated with CCH during the active phase achieved comparable outcomes to those in the stable phase. There were no additional adverse events in the active phase treatment group. These data suggest that early active phase treatment yields similar effectiveness as treatment administered during the stable phase. Treatment during the active phase could be a disease modifier and may change the course of progression. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Endo, Roman Health.

(395) Safety and Efficacy of Collagenase Clostridium Histolyticum in Peyronie's Disease Men with Ventral Curvatures

Abstract Introduction Limited data are available on the efficacy of collagenase clostridium histolyticum (CCH) on Peyronie’s disease (PD) in men with ventral curvatures. Our team previously published a limited series of outcomes of 25 men with ventral curvatures who underwent CCH. Given the paucity of data available, we sought to provide an updated series of outcomes in this important cohort. Objective To report outcomes of men undergoing CCH injections for PD based on initial direction of curvature, including absolute and percent improvement in curvature, adverse events (AE), and other subjective outcomes. Methods A prospective registry has been maintained of all men undergoing CCH injections since 2014. All men underwent curvature assessments and subjective questioning at the time of initial evaluation and prior to each subsequent series of injections. The method of injection and subsequent protocol have changed in a stepwise fashion since 2014 and currently include injecting 0.9 mg (diluted to 0.8 mL) on back-to-back days, injecting into the point of max curve with an erection on day 1, performing in-office modeling on day 2, utilizing Restorex traction beginning on day 2, and wrapping for 4-8 days depending on results. To review outcomes, clinicopathologic data were abstracted from the registry including relevant history, exam, and data obtained at the time of penile ultrasound and curvature assessment. Outcomes are reported using a “Most Recent” definition (most recent data point used, regardless if the patient continues or finished treatment) and “Completed 8 or Satisfied” (only included if the patient indicated that they were done with treatment or had finished the full 8 injections). Results A total of 560 patients (mean age 57 years) were identified from March 2014 through Feb 2023 and comprise our study cohort. Overall, 85 men had a ventral component to their curvature and 475 non-ventral. Baseline demographics and clinical factors were similar between groups, with the exception of penile length (ventral 14.0 cm, non-ventral 12.0 cm, p&amp;lt;0.0001), Psych and Physical subdomain of the Peyronie’s Disease Questionnaire (10 vs 12, p=0.03), and prior treatment with CCH (3% vs 16%, p=0.03). Following treatment, men in the ventral cohort exhibited possibly greater improvements in curvature (Most Recent Definition: -25 degrees vs -24, p=0.08; 45% vs 34%, p=0.03; Completed 8 or Satisfied Definition: -35 vs -25, p&amp;lt;0.05, 48% vs 38%, p=0.11). However, all other outcomes were similar between cohorts, including differences in subdomains of the IIEF and PDQ, use of traction therapy, and adverse events including ecchymoses, hematomas, and popping sensations. Importantly, no urethral complications were experienced in the ventral group. Conclusions Men with ventral PD may be effectively treated with CCH with similar AEs compared to other directions. Ventral curvatures are likely associated with greater overall curvature improvements compared to other directions. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Endo - Matt Ziegelmann.

Parametric Expansions of an Algebraic Variety Near Its Singularities II

The paper is a continuation and completion of the paper Bruno, A.D.; Azimov, A.A. Parametric Expansions of an Algebraic Variety Near Its Singularities. Axioms 2023, 5, 469, where we calculated parametric expansions of the three-dimensional algebraic manifold Ω, which appeared in theoretical physics, near its 3 singular points and near its one line of singular points. For that we used algorithms of Nonlinear Analysis: extraction of truncated polynomials, using the Newton polyhedron, their power transformations and Formal Generalized Implicit Function Theorem. Here we calculate parametric expansions of the manifold Ω near its one more singular point, near two curves of singular points and near infinity. Here we use 3 new things: (1) computation in algebraic extension of the field of rational numbers, (2) expansions near a curve of singular points and (3) calculation of branches near infinity.

Consequences of Rényi entropy on the thermal geometries and Hawking evaporation of topological dyonic dilaton black hole

Abstract The thermodynamics of black holes (BHs) has had a profound impact on theoretical physics, providing insight into the nature of gravity, the quantum structure of spacetime and the fundamental laws governing the Universe. In this study, we investigate thermal geometries and Hawking evaporation of the recently proposed topological dyonic dilaton BH in anti-de Sitter (AdS) space. We consider Rényi entropy and obtain the relations for pressure, heat capacity and Gibbs free energy and observe that the Rényi parameter and dilaton field play a vital role in the phase transition and stability of the BH. Moreover, we use Weinhold, Ruppeiner and Hendi Panahiyah Eslam Momennia models to evaluate the scalar curvature of the BH and find out that the divergence points of the scalar curvature coincides with the zero of specific heat. Finally, using Stefan–Boltzmann law, we determine that the BH without a dilaton field evaporates far more quickly compared to the dilaton BH in AdS space.

Macroscopic and microscopic analysis of the effects of moisture content and dry density on the strength of loess.

To clarify the impact of moisture content and dry density on the strength of loess, the remolded loess samples with different moisture content and dry density were prepared, and the influence of moisture content and dry density on loess strength was explored from the macro level by direct shear test without suction control. On this basis, the mechanism of the influence of moisture content and dry density on loess strength was explored from the micro level by nuclear magnetic resonance method. The research results indicate that: In the case of low water content, there are peak points in the stress-strain curve of remolded loess, exhibiting strain softening characteristics. In the case of high water content, there is no obvious peak in the stress-strain curve, exhibiting strain hardening characteristics. Moisture has a significant impact on the shear strength of remolded loess. As the moisture content of the soil sample increases, the cohesion decreases significantly, and the change in internal friction angle is not obvious. As the moisture content continues to increase, the free water content continues to increase. Free water will continuously soften the soil particle structure, reduce the bonding force between soil particles, and cause the cohesion to decrease with the increase of moisture content. The change in dry density also has a significant impact on the shear strength parameters of remolded loess. As the dry density of the soil sample increases, the cohesion increases. The smaller the dry density, the larger the pore ratio, and the looser the contact between soil particles, weakening the bonding effect. The larger the pore ratio, the more bound water is converted to free water, and the strong bonding force between the water film and soil particles disappears. Both of these microscopic factors can lead to a decrease in cohesion with a decrease in dry density.