Penetration Model Research Articles

Novel corticotropin-releasing hormone receptor genes (CRHR1 and CRHR2) linkage to and association with polycystic ovary syndrome

BackgroundWomen with polycystic ovarian syndrome (PCOS) have increased hypothalamic–pituitary–adrenal (HPA) axis activation, pro-inflammatory mediators, and psychological distress in response to stressors. In women with PCOS, the corticotropin-releasing hormone (CRH) induces an exaggerated HPA response, possibly mediated by one of the CRH receptors (CRHR1 or CRHR2). Both CRHR1 and CRHR2 are implicated in insulin secretion, and variants in CRHR1 and CRHR2 genes may predispose to the mental-metabolic risk for PCOS.MethodsWe phenotyped 212 Italian families with type 2 diabetes (T2D) for PCOS following the Rotterdam diagnostic criteria. We analyzed within CRHR1 and CRHR2 genes, respectively, 36 and 18 microarray-variants for parametric linkage to and/or linkage disequilibrium (LD) with PCOS under the recessive with complete penetrance (R1) and dominant with complete penetrance (D1) models. Subsequentially, we ran a secondary analysis under the models dominant with incomplete penetrance (D2) and recessive with incomplete penetrance (R2).ResultsWe detected 22 variants in CRHR1 and 1 variant in CRHR2 significantly (p < 0.05) linked to or in LD with PCOS across different inheritance models.ConclusionsThis is the first study to report CRHR1 and CRHR2 as novel risk genes in PCOS. In silico analysis predicted that the detected CRHR1 and CRHR2 risk variants promote negative chromatin activation of their related genes in the ovaries, potentially affecting the female cycle and ovulation. However, CRHR1- and CRHR2-risk variants might also lead to hypercortisolism and confer mental-metabolic pleiotropic effects. Functional studies are needed to confirm the pathogenicity of genes and related variants.

Application of laboratory-based rate of penetration model for polycrystalline diamond compact bit to geothermal well drilling

The modeling of the rate of penetration (ROP) considering the degradation of drilling performance owing to bit wear is essential for planning efficient and economical drilling. In the present study, a laboratory-based ROP model for a polycrystalline diamond compact (PDC) bit is reviewed and the applicability of the model to the field data obtained in the four drilling tests performed by drilling structural boring wells in geothermal regions is investigated. It is validated that, on the whole, a parameter representing bit performance exponentially decreased with drilled length, suggesting that the decrease in ROP owing to bit wear is appropriately considered by the model, except when inherent performance of a PDC bit is not sufficiently exerted for some reason, e.g., inefficient transport of cuttings. The findings of the present study are expected to contribute to the optimization of drilling plans, including appropriate bit selection and bit life estimation.

Maintenance modeling and cost assessment for repaired reinforced concrete structures exposed to chloride attack in coastal areas in Vietnam

One of the primary causes that can reduce the lifespan of concrete structures is chloride-induced corrosion of reinforcing steel. Recent research has shown that material properties, exposure conditions and climatic conditions have a significant influence on the structural deterioration of reinforced concrete (RC) structures, especially in marine environments. The objective of this paper is to predict the durability of RC structures damaged by chloride-induced corrosion in near-shore environments in Vietnam, considering regular repair activities. A two-dimensional model of chloride penetration in square cross-section RC columns repaired by cover replacement techniques is studied. Two repair methods with different shapes (orthogonal and circular) are considered. The effects of the different repair methods on the life span of structures are investigated in case studies in Vietnam that consider the variations of annual temperature and humidity in three coastal areas such as Danang, Haiphong, and Ho Chi Minh City. Finally, maintenance and repair costs during the lifetime of structures are calculated for each case. The study suggests that for RC structures exposed to two-dimensional chloride ingress, the most critical areas for assessing chloride concentration, predicting corrosion initiation, and planning repair schedules are the corners of the columns. In addition, the chloride-induced corrosion process is strongly influenced by the local weather conditions, especially in areas with high humidity. The repair method with circular concrete replacement seems to be more efficient in terms of maintenance schedule and cost than the repair method with orthogonal concrete replacement.

CNN Based Plant Disease Identification Using PYNQ FPGA

Plant disease is an ongoing challenge for smallholder farmers, which threatens income and food security. The recent revolution in smartphone penetration and computer vision models has created an opportunity for image classification in agriculture. Convolutional Neural Networks (CNNs) are considered state-of-the-art in image recognition and offer the ability to provide a prompt and definite diagnosis. In this paper, the performance of a pre-trained ResNet34 model in detecting crop disease is investigated. The developed model is deployed as a web application and is capable of recognizing 7 plant diseases out of healthy leaf tissue. A dataset containing 8,685 leaf images; captured in a controlled environment, is established for training and validating the model. Validation results show that the proposed method can achieve an accuracy of 97.2% and an F1 score of greater than 96.5%. This demonstrates the technical feasibility of CNNs in classifying plant diseases and presents a path towards AI solutions for small holder farmers.

A single motor-driven continuum robot that can be designed to deform into a complex shape with curvature distribution

This paper proposes a method to deform a continuum robot into a complex shape with distributed curvature using a single motor drive. This continuum robot can be deformed to a desired shape by placing tendon guides at appropriate intervals. We used several target shapes, including clothoid and sin curves, as well as a circular curve of constant curvature and confirmed that the deformed shapes match them both in the simulation and prototype. This paper proposes two models of continuum robots. One is the Plain Model in which the tendons are parallel to the rod and the Penetration Model in which the tendon penetrates to the rod. By placing the penetrating position(s), this continuum robot can be deformed into a shape with inflection point(s). We designed a mathematical model to simulate the deformed shape of the prototype to obtain the proper placement of the guides and penetration point(s). Through the optimization, it was able to find the parameters that, in most cases, result in the error of less than 4% between the target and deformed shapes on simulation. We applied these conditions to the prototype and evaluated the errors, which were approximately 10%, the same as the related works that use a conventional constant curvature model. We think that the results of this paper can be applied to reduce the number of actuators required and the size and weight of continuum or biomimetic robots.

Investigations on the Diesel Spray Characteristic and Tip Penetration Model of Multi-Hole Injector with Micro-Hole under Ultra-High Injection Pressure

Increasing the injection pressure has a significant impact on atomization and combustion characteristics. Spray tip penetration serves as a vital parameter for fuel injection control and engine structure design. However, a reliable spray tip penetration model for ultra-high-pressure injection is currently lacking. To address this gap, this study establishes a theoretical 0-dimensional model for spray tip penetration under ultra-high pressure (300 MPa) conditions. The model is based on the conservation of momentum and phenomenological models. The new model divides spray tip penetration into two stages: Pre-breakup and post-breakup, with fuel injection rate and spray cone angle used as model inputs. To validate the model, high-speed camera observations and constant-volume chamber experiments are conducted to investigate the spray characteristics. The results indicate that the new spray tip penetration model demonstrates improved predictive accuracy across all experimental conditions.

Analysis of a Mechanical Anchoring System for Landing on Asteroids

The landing process to an asteroid is discussed with a Nimble Lander. The miniature harpoons are chosen as the anchoring device to landing to asteroid in the Nimble Lander. The analysis results provide detailed information of the anchoring with harpoon as anchoring device. Many different designs of harpoon have been tested by simulation, the best of three designs of harpoon are analyzed for anchoring to Apophis. Instead of the modelling of the anchor as a rigid cylindrical projectile in penetration models, the deformation of the harpoon is fully considered in the anchoring analysis. The analysis provides ground base a reliable design anchoring system for landing to Asteroids.

Raman Spectroscopy to Monitor the Delivery of a Nano-Formulation of Vismodegib in the Skin

Raman spectroscopy was used to detect low quantities of Vismodegib in the skin after its topical application via transfersomes. Vismodegib is a novel antineoplastic drug approved for oral administration for treatment of basal cell carcinoma. Transfersomes loaded with Vismodegib were prepared by thin film resuspension and extrusion, and were characterized physicochemically. Transfersomes were applied to human and pig skin specimens using the Saarbrücken penetration model. The skin was then sectioned by tape stripping, followed by penetration assessment by UV-Vis spectroscopy and Raman spectroscopy in a confocal Raman microscope. Raman signals from Vismodegib and transfersomes were recovered from skin sections, showing a similar distribution in the stratum corneum obtained by the other techniques. On the other hand, pig and human skin showed differences in their penetration profiles, proving their lack of equivalence for assessing the performance of these transfersomes. Raman spectroscopy appears as a potential non-invasive, direct tool for monitoring hard-to-detect molecules in a complex environment such as the skin.

Experimental modelling of spudcan penetration in spatially variable soils

ABSTRACT The influence of spatial variability of soils on spudcan penetration responses is found significant through numerical methods. However, due to the difficulty of preparing spatially variable soils, the penetration mechanism of the spudcan through random soils remains physically unclear. Therefore, this study aims to investigate the effects of the spatial variability of soils on the penetration behaviour of spudcan foundations by laboratory tests. A new method to prepare the spatially variable soils was proposed first. Then, three physical soil models with different scales of fluctuation and coefficients of variation were carefully prepared. The spudcan penetration was conducted in these three soil models and the penetration mechanism of the spudcan was investigated. The penetration resistances of the three cases were obtained and compared with that predicted by the methods suggested by ISO and SNAME standards. The results show that the predicted error of the penetration resistance can reach 50% when the soils have a large coefficient of variation and a small horizontal scale of fluctuation. The large difference is the significant spatial variability that has been ignored in the standards. This study paves the way to an accurate prediction of the spudcan penetration analysis in strong variable soil seabed.

Development of a dynamic ice penetration model for runway de-icing products through performance experimental characterization

During winter, the clear runway concept is crucial to airports for maintaining passenger and employee safety. Research can optimize de-icing product application rates, thereby reducing costs and environmental impact. Currently, three aerospace standards exist for evaluating the performance of runway de-icing products. These comparative tests—ice melting, ice undercutting, and ice penetration tests—are carried out jointly in a systematic way and indicate whether a runway de-icing product is effective in actively reducing the presence of ice. Here we present a numerical model for the ice penetration method, for fluid runway de-icing product, with the goal of deepening the knowledge in this field. We apply a series of laboratory-based tests to measure the performance of runway de-icing products, and develop a new model to analyze the behavior of each product. The principal observation is that the product is more effective at 1 min and effectiveness decreases following an inverse logarithmic curve trend to 30 min. Through modeling, we observe that the dominant mode of heat transfer is natural laminar convection, and the model predicts a uniform melt length for the entire tube section. Thus, simplified ice penetration modeling using AS6211 can acceptably predict the rate of ice penetration as a function of time (mm/min), with the modeling confirmed by our experimental results. The future application of our simplified model to other existing de-icing fluid characterization test methods could identify the effects of diluted or undiluted solid runway de-icing products on ice penetration rates and ultimately on spreading rates.

Experimental and Simulation Investigation of Total Dissolved Gas Prediction in Supersaturated Water Treatment: Focusing on Source Calibration and Combining with Bubble Coalescence

Supersaturation of total dissolved gas (TDG) is a common occurrence in high dams during the spill process, which can lead to fish bubble disease and threaten aquatic organisms. As a result, many scholars have taken a keen interest in this issue. Research into the gas-liquid mass transfer mechanism has improved the accuracy of TDG prediction models. This article investigates the factors affecting TDG dissipation through laboratory experiments. Especially, the mass transfer coefficient across the bubble interface based on the slip penetration model was calibrated, and the coaxial bubble coalescence added to the coefficient was studied. The results show that the aeration rate has the most significant impact, followed by water depth, and then the aeration aperture. The TDG dissipation rate increases with the parameter β, and the parameter of 0.35 shows the highest correlation with the experimental data. Furthermore, the concentration change rate after coalescence is lower than before, suggesting that aggregation negatively impacts mass transfer. This study improves TDG concentration prediction accuracy and proposes measures for mitigating supersaturation to avoid fish bubble disease.

Experimental testing on timber connections considering the influence of gap size and intumescent sealants

AbstractThis paper investigates the influence of gap size (openings/spaces between two structural members) and the presence of intumescent sealants on the development of temperature when timber connections are exposed to fire conditions. The experimental results of 21 samples representing a concealed steel‐to‐timber connection configuration that was exposed with a 0, 3, 6, and 10 mm gap to the ISO834 standard fire for 120 min are presented. Half of the samples in each sample group were protected with an intumescent fire protection sealant. The temperatures in the timber were measured at various locations around the gap and directly next to the steel component. The experimental results show that the presence of a gap increases the temperature of the timber more than predicted by the thermal penetration models available, with current code guidelines (e.g., Eurocode 5) possibly being non‐conservative. The use of an intumescent fire protection sealant in the gap is shown to be an effective protection method, but that the application configuration is important to ensure effective protection, especially as the gap becomes smaller. The results also show that the use of an intumescent fire protection sealant in a gap increases the predictability of the temperatures in the timber in longer duration fires. Unprotected samples and 0 mm gap samples exhibited large variability in the thermal development outcomes over time.

Penetrator Penetrating Lunar Soil: Accurate Modeling and Parameter Analysis

This paper focuses on how to establish an accurate numerical model of penetrator penetration into the lunar soil and study the process of penetration. The lunar soil simulant was prepared according to published literature, and its plastic parameters were obtained by triaxial compression test. To determine the material model and parameters of the lunar soil simulant in numerical simulation, the corresponding numerical simulation was carried out for the triaxial test. Under the comprehensive consideration of accuracy and computational efficiency, the applicability of four numerical algorithms, including finite element method (FEM), arbitrary Lagrangian–Eulerian, smoothed particle hydrodynamics (SPH), and SPH–FEM, in the penetration simulation is evaluated. Finally, SPH–FEM is the optimal algorithm for the numerical simulation of the penetrator penetrating lunar soil. The convergence of the penetration model is tested. Finally, an accurate numerical model of the penetrator penetrating lunar soil is obtained. Then, the effects of incident velocity, incident angle, and angle of attack on penetration performance are studied, respectively, which provide reference for the design and process control of the penetrator project.

Dendrite initiation and propagation in lithium metal solid-state batteries.

All-solid-state batteries with a Li anode and ceramic electrolyte have the potential to deliver a step change in performance compared with today's Li-ion batteries1,2. However, Li dendrites (filaments) form on charging at practical rates and penetrate the ceramic electrolyte, leading to short circuit and cell failure3,4. Previous models of dendrite penetration have generally focused on a single process for dendrite initiation and propagation, with Li driving the crack at its tip5-9. Here we show that initiation and propagation are separate processes. Initiation arises from Li deposition into subsurface pores, by means of microcracks that connect the pores to the surface. Once filled, further charging builds pressure in the pores owing to theslow extrusion of Li (viscoplastic flow) back to the surface, leading to cracking. By contrast, dendrite propagation occurs by wedge opening, with Li driving the dry crack from the rear, not the tip. Whereas initiation is determined by the local (microscopic) fracture strength at the grain boundaries, the pore size, pore population density and current density, propagation depends on the (macroscopic) fracture toughness of the ceramic, the length of the Li dendrite (filament) that partially occupies the dry crack, current density, stack pressure and the charge capacity accessed during each cycle. Lower stack pressures suppress propagation, markedly extending the number of cycles before short circuit in cells in which dendrites have initiated.

Prediction of the Penetration Radius of Cumulative Blasting.

To improve the efficiency of coal seam gas extraction, the influence characteristics of different factors on the penetration effect of cumulative blasting were determined and the hole spacing was effectively predicted; in this work, we used ANSYS/LS-DYNA numerical simulation software to establish the penetration model of cumulative blasting. Combined with an orthogonal design scheme, the crack radius prediction of cumulative blasting was studied. A prediction model for predicting the fracture radius of cumulative blasting based on three groups of different factors was established. The results showed that the primary and secondary order of factors that affected the fracture radius of cumulative blasting was as follows: ground stress > gas pressure > coal firmness coefficient. The penetration effect decreased with increasing ground stress and decreased with an increase in the gas pressure and coal firmness coefficient. The industrial field test was carried out. The gas extraction concentration increased by 73.4% after cumulative blasting, and the effective crack radius of cumulative blasting was approximately 5.5-6 m. The maximum error of the numerical simulation was 1.2%, and the maximum error of the industrial field test was 6.22%, which proved that the crack radius prediction model of cumulative blasting was correct.

Numerical modeling of wave penetration inside a harbor

Wave penetration analysis is typically performed to ensure that the coastal structure at the harbour provides adequate shelter from waves and currents for ship berthing. Generally, wave penetration inside a harbour occurs through the entrance. The type of coastal protection (usually a breakwater) also has an impact on wave agitation within the harbour. In this research, wave penetration analysis has been done, mainly, by using MIKE 3 Wave FM software to model seven different scenarios as individual cases. From the seven different cases, the mean wave disturbance coefficient and mean significant wave height in the berthing area are determined. The model results showed that the wave penetration on the turning circle in the navigation channel is relatively unaffected by the wave disturbance in all seven cases. It is observed that 80 % of the time the significant wave height in the berthing area was less than or equal to 0.1 meters. The wave climate in the berthing area is therefore classified as good. Consequently, it can be concluded that the breakwaters are achieving their goal of reducing the impact of wave action and currents within the harbour.

Complexes formed between polyelectrolyte and acetylated cationic dendrimers

Gene therapies are receiving a revival, especially because of the potential for use in cancer and infectious disease vaccination. However, effectively condensing and maintaining deoxyribonucleic acid (DNA) carriers for gene therapy are used, such as dendrimers. The penetrable sphere model developed by Qamhieh et al., explain the interaction between linear polyelectrolyte (LPE) and an ion-penetrable sphere was employed to study the complexation of negatively charged DNA and acetylated dendrimer. Throughout the study, we emphasized the effect of acetylation on two types of complexations: single dendrimer-DNA chain complex and multiple dendrimers-DNA chain complex. The interaction between three different DNA lengths: L = 90 nm of 265; L = 184 nm of 541 bp; and L = 680 nm of 2000 bp individually with the poly (amido amine) (PAMAM) dendrimer of generation 5 was studied. For a single dendrimer-DNA complex, the number of condensed monomers around the dendrimer and the fraction of optimal length wrapping around the dendrimer was studied. It was found that by increasing acetylation, the number of condensed monomers and the fraction of optimal length decreased. For multiple dendrimers-DNA complex, the optimal length wrapping around the dendrimer and the linker that forms between complexes were studied. As a result, with increasing acetylation, the will shorten while the linker will increase significantly. The acetylation also affected the number of turns wrapping around the dendrimer and the net charge of the complex for single and multiple dendrimer-DNA complexes, and it was found that the longer the chain length, the more turns there are around the dendrimer. The net charge of all complexes was negative due to increased acetylation. In this study, it is revealed that the developed model is suitable for demonstrating the complexation between the dendrimer and the DNA.

A reduced-turbulence regime in the Large Helical Device upon injection of low-Z materials powders

Recently an improved confinement regime, characterized by reduced turbulent fluctuations has been observed in the Large Helical Device upon the injection of boron powder into the plasma (Nespoli et al 2022 Nat. Phys. 18 350–56). In this article, we report in more detail the experimental observations of increased plasma temperature and the decrease of turbulent fluctuations across the plasma cross section, on an extended database. In particular, we compare powders of different materials (B, C, BN), finding similar temperature improvement and turbulence response for the three cases. Modeling of the powder penetration into the plasma and of neoclassical electric field and fluxes support the interpretation of the experimental results. Additionally, we report evidence of the temperature improvement increasing with powder injection rates and decreasing for both increasing density and heating power. Though, plasma turbulence response varies depending on the initial conditions of the plasma, making it difficult to draw an inclusive description of the phenomenon.

Experimental nuclear charge density and theoretical description of the above-barrier light heavy-ion fusion process* *Supported by the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS.”

Theoretical modeling of nucleus-nucleus collisions is often based on the nucleus-nucleus potential. One of the advanced methods for constructing this potential is the semi-microscopical double-folding model with M3Y-Paris NN-forces. Proton and neutron densities are significant components of this model. The correct nucleon density (ND) must reproduce the experimental nuclear charge density (NCD). However, those who deal with modeling the fusion process typically disregard this circumstance. We aim to achieve a good description of both the nuclear charge density and above-barrier fusion cross sections of even-even light nuclei with . We consider several versions of NDs available in literature and construct our own approximation for the ND of the even-even spherical nuclei 12C, 16O, and 40Ca, abbreviated as FE-density (Fermi+exponential). We carefully compare the NCDs resulting from different versions of NDs with the experimental NCDs. After finding the nucleus-nucleus potential using the double-folding model with the density dependent M3Y-Paris NN-forces and FE densities, we evaluate the above-barrier fusion cross sections for five reactions, 12C+12C, 12C+16O, 16O+16O, 16O+40Ca, and 40Ca+40Ca, for which experimental data are available. The cross sections are calculated using two approaches: a) the barrier penetration model and b) the trajectory model with surface friction (TM). To find the transmission coefficients for the TM, the Langevin equations are employed. For all considered reactions, our TM typically reproduces the above-barrier experimental cross sections within 10−15%. The only adjustable parameter of the model, the optimal friction strength , is found to be approximately 90 for the light reactions 12C+12C, 12C+16O, and 16O+16O and approximately 15 for the heavy reactions 16O+40Ca and 40Ca+40Ca. The latter findings are in reasonable agreement with the systematics found previously. Thus, the FE-recipe allows highly accurate and simultaneous reproduction of both the nuclear charge density and above-barrier fusion cross sections of five reactions involving 12C, 16O, and 40Ca nuclei.

Axial-torsional nonlinear vibration of bottom hole assembly in the air drilling technology

The safety and efficiency of drilling engineering are greatly impeded by destructive vibrations of drill string in air drilling, such as stick-slip, bit-bounce and their coupled vibrations. To avoid or suppress these vibrations improving the stability of drilling operations, revealing the occurrence mechanisms of abovementioned harmful vibrations are indispensable by investigating dynamics characteristics of drill string system. In this paper, an axial-torsional coupled dynamics model that can capture the motion behaviors of bottom hole assembly (BHA) is established adopting the lumped parameter method. Subsequently, a rate of penetration (ROP) model appropriating for air drilling is obtained firstly by linear fitting means. Meanwhile, a novel discontinuous support model is established to describe the bit-formation interactions. Then, BHA dynamics are discussed using numerical simulations under different vibration scenarios: normal operation; stick-slip; bit-bounce; bit-bounce and stick-slip combination. Subsequently, in two drilling modes: the continuous and intermittent drilling, the vibration mitigation strategies and dynamics sensibility study of BHA are carried out based on the parametric analysis. The results show that increasing torsional stiffness of drill-pipes, appropriately adjusting rotation speed of top driven system and dynamic weight on bit (WOB) are deemed as an effective strategy suppressing or eliminating stick-slip and bit-bounce vibrations of BHA. Suggest that the rotation speed of top driven system and dynamic WOB are 5 rad/s and 3.5 kN, respectively. Finally, the constructed probability maps allow to driller to choose reasonable mechanical parameters, thereby realizing smooth drilling operation in the air drilling.