Penetration Depth Research Articles

Comparison of different cementing techniques for cement penetration under tibial component in total knee arthroplasty: a retrospective observational study

PurposeThis study aimed to investigate the differences in cement penetration between cementing techniques in total knee arthroplasty (TKA).Materials and methodsWe retrospectively evaluated knee undergone TKA at our hospital for both preoperative and postoperative computed tomographic (CT) evaluations. Cementing was performed with hand mixing and hand packing (HM group) and with vacuum mixing and cement gun use (VM group). We measured the area under the tibial baseplate (sclerotic and nonsclerotic sides) and compared the mean and maximum depths of cement penetration at each area.ResultsOf the 44 knees evaluated, 20 and 24 knees were in the HM and VM groups, respectively. At the center of the sclerotic side, the mean penetration depths (2.0 ± 0.7 and 2.5 ± 0.7 mm, p = 0.02) and the maximum penetration depths (4.0 ± 0.9 and 5.0 ± 1.6 mm, p = 0.02) were significantly deeper in the VM group than in the HM group. The correlation between preoperative Hounsfield unit values and mean penetration were r = –0.617 (p < 0.01) and –0.373 (p = 0.01) in the HM and VM groups, respectively.ConclusionThe cementing technique of vacuum mixing and using a cement gun allowed for deeper cement penetration compared with the hand mixing and hand packing technique, even in bone sclerotic sites.

The Not-so Dramatic Effect of Advective Flows on Gas Accretion

Super-Earths and mini-Neptunes are the most common types of exoplanets discovered, yet the physics of their formation are still debated. Standard core accretion models in gas-rich environments find that typical mini-Neptune mass planets would blow up into Jupiters before the underlying disk gas dissipates away. The injection of entropy from the protoplanetary disk into forming gaseous envelopes has recently been put forward as a mechanism to delay this runaway accretion, specifically at short orbital distances. Here, we reevaluate this line of reasoning by incorporating recycling flows of gas into a numerical one-dimensional thermodynamic model with a more realistic equation of state and opacities and the thermal state of the advective flow. At 0.1 au, we find that advective flows are only able to produce mini-Neptunes if they can penetrate below ∼0.25 of the planet’s gravitational sphere of influence. Otherwise, the gas-to-core mass ratio (GCR) reaches above ∼10%, which is too large to explain the measured properties of mini-Neptunes, necessitating other gas-limiting processes such as late-time core assembly. The effect of entropy advection on gas accretion weakens even further beyond 0.1 au. We present an updated scaling relation between GCR and the penetration depth of the advective flows, which varies nontrivially with orbital distances, core masses, and dusty versus dust-free opacity. We further demonstrate how measurements of planet mass distribution beyond ∼1 au using future instruments such as the Nancy Grace Roman Space Telescope could be used to disambiguate between different formation conditions of gas-poor planets.

A general solution for the water entry of an arbitrary curved wedge

ABSTRACT The present study proposes a general solution for the water entry of an arbitrary curved wedge with a constant speed. The solution is based on the assumption that the impact flow is an incompressible potential flow with negligible effects of gravity and surface tension. The slamming and transition stages of the water entry of the curved wedge are addressed theoretically. For the slamming stage, pressure and hydrodynamic force models are derived from a quasi self-similar assumption based on the wetted length and a similarity solution of the water entry of linear wedges. The solution can be applied to the water entry of linear and curved wedges, where the curvature effects are absorbed into the wetted length and the derivative of the wetted length with respect to the penetration depth. For the transition stage, where a fixed separation point of flow detachment is located at the knuckle of the wedge, a hydrodynamic force model is proposed by extending the transition stage model of the water entry of linear wedges to that of curved wedges. The present solution can quickly predict the pressure distributions and hydrodynamic forces for the water entry of curved wedges. The predictions are in good agreement with the experimental and numerical results for the slamming and transition stages.

Analyzing the effect of different shielding atmospheres on fiber laser welding parameters for modified 9Cr-1Mo steel

The present research aims to investigate the influence of and the relationship between welding speed ( v), focal position ( FP), and laser power ( LP) as input parameters for fiber laser to weld P91 under pure argon and CO2 shielding atmospheres using response surface methodology and using the desirability approach; optimization of input parameters has been performed to maximize the depth of penetration ( DP) while minimizing the top bead width ( TW) and heat-affected zone width ( HW). The results indicate that laser power ( LP) has the most significant impact on depth of penetration ( DP), whereas welding speed ( v) affects top bead width ( TW) and heat-affected zone width ( HW). The optimal combination of parameters under argon shielding results in a significantly low heat input of 48 J/mm (0.048 kJ/mm) and 50 J/mm (0.050 kJ/mm) pure argon and CO2 shielding atmospheres, respectively. Despite the difference in heat input being only 4.08%, an 11.618% increase in DP is observed under the CO2 shielding atmosphere. Due to the high-speed nature of the welding process (argon: 82.65 mm/s and CO2: 79.283 mm/s) combined with the significant reduction in heat input, the heat-affected zone is limited to a mere width of 0.203 mm under an argon shielding atmosphere and 0.263 mm under the CO2 shielding atmosphere compared with that reported in the other welding processes without the dissolution of precipitates in the fusion boundary of heat-affected zone. Microstructural characterization of the fusion zone has revealed the presence of an untempered lath martensite structure with precipitate dissolution. The precipitate dissolution has resulted in grain coarsening of 47.76% in argon weld and 39.65% in CO2 weld compared with the base metal grain size of 6.07 µm.

Beyond absorption maxima: the impact of wavelength-resolved photochemistry on materials science.

Reflecting on Giacomo Ciamician's revolutionary vision of harnessing sunlight to drive photochemical transformations, the field of materials science has evolved significantly, yet it has been constrained by the misconception that the highest reactivity in photochemical systems is achieved at the absorption maxima. Here, we explore this notion further with evidence from photochemical action plots, demonstrating that reactivity can indeed be maximal at wavelengths significantly separated from the absorption peak. By examining the implications of the disparity between absorptivity and photochemical reactivitiy, we explore its impact for the enhanced penetration depth of light in photoresists, the reduction of energy requirements for photochemical reactions, and its transformative potential for volumetric 3D printing. Ultimately, we argue for a renewed appreciation of light's capability to facilitate photochemical reactions across the entire volume of a material.

An experimental investigation into the potential of employing mixed eco-friendly abrasives during AWJ milling of nickel-based superalloy

AbstractNon-conventional machining processes are capable of achieving higher performance compared to conventional ones due to their inherent characteristics and higher amount of parameters which can be favorably regulated. Although the correlation between the most important process parameters and process outcome has been already established for a wide range of conditions and workpiece materials, the introduction of new considerations related to the three pillars of sustainability require further investigation on new means for the enhancement of AWJ milling process. As one of the most important parameters in AWJ milling is the abrasive material, the introduction of new materials may offer considerable advantages from different perspectives. Thus, in the present work, a comprehensive investigation on the efficiency of using eco-friendly, mixed abrasives is carried out under various conditions such as different traverse feed rate, abrasive mass flow rate, water jet pressure, jet impingement angle, and mixing ratio. The feasibility of using mixed abrasives is evaluated in terms of achievable depth of penetration, kerf width, kerf taper angle as well as material removal rate (MRR), and cutting efficiency. The findings indicate that among other factors, the mixing ratio plays a noticeable role especially regarding MRR and cutting efficiency and can offer an additional effective means to achieve the desired kerf characteristics in conjunction with other significant parameters such as water jet pressure.

Optimization and Analysis of Refill Friction Stir Spot Welding (RFSSW) Parameters of Dissimilar Aluminum Alloy Joints by FE and ANN Methods

The quality of the refill friction stir spot welding (RFSSW) process is heavily dependent on the selected welding parameters that influence the resultant joint characteristics. Thermomechanical phenomena integral to the process were investigated using finite element (FE) analysis on two dissimilar materials. This FE analysis was subsequently validated through controlled experiments to ensure reliability. An artificial neural network (ANN) was employed to create a neural model based on an experimental setup involving 120 different sets of welding parameters. The parameters adjusted in the experimental plan included pin penetration depth, rotational speed, retention time, and positioning relative to material hardness. To assess the neural model’s accuracy, outputs such as maximum temperature and normal stress at the end of the welding process were analyzed and validated by six data sets selected for their uniform distribution across the training domain.

Multi-parametric Photoacoustic Imaging Combined with Acoustic Radiation Force Impulse Imaging for Applications in Tissue Engineering.

Tissue engineering is a dynamic field focusing on the creation of advanced scaffolds for tissue and organ regeneration. These scaffolds are customized to their specific applications and are often designed to be complex, large structures to mimic tissues and organs. This study addresses the critical challenge of effectively characterizing these thick, optically opaque scaffolds that traditional imaging methods fail to fully image due to their optical limitations. We introduce a novel multi-modal imaging approach combining ultrasound, photoacoustic, and acoustic radiation force impulse imaging. This combination leverages its acoustic-based detection to overcome the limitations posed by optical imaging techniques. Ultrasound imaging is employed to monitor the scaffold structure, photoacoustic imaging is employed to monitor cell proliferation, and acoustic radiation force impulse imaging is employed to evaluate the homogeneity of scaffold stiffness. We applied this integrated imaging system to analyze melanoma cell growth within silk fibroin protein scaffolds with varying pore sizes and therefore stiffness over different cell incubation periods. Among various materials, silk fibroin was chosen for its unique combination of features including biocompatibility, tunable mechanical properties, and structural porosity which supports extensive cell proliferation. The results provide a detailed mesoscale view of the scaffolds' internal structure, including cell penetration depth and biomechanical properties. Our findings demonstrate that the developed multimodal imaging technique offers comprehensive insights into the physical and biological dynamics of tissue-engineered scaffolds. As the field of tissue engineering continues to advance, the importance of non-ionizing and non-invasive imaging systems becomes increasingly evident, and by facilitating a deeper understanding and better characterization of scaffold architectures, such imaging systems are pivotal in driving the success of future tissue-engineering solutions.

Enhancing structural protection of reinforced concrete structures against high dynamic loads using post-installed UHPFRC/UHPFRSC

Recently there has been an observed change in security policy across the globe which implies that humanity must prepare for hybrid and asymmetric acts of war. This security situation will result in spontaneous attacks from non-military groups. The threats include ballistic attacks from commercially available weapons, detonation of explosives, and impact of vehicles. These attacks are focused on critical infrastructures. Reinforced concrete (RC) elements with ballistic and explosion protection are of huge relevance. This requires new concepts and innovative solutions for the protection of new buildings and/or for the strengthening of existing structures. In this paper a method for the increase of structural safety is shown using Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) or sprayed UHPFRC, so called UHPFRSC, as a surface layer for reinforced concrete structures. The UHPFRC/UHPFRSC is applied in thin layers of 30 - 80 mm on the protection side. The interaction of the two different cementitious materials results in increased resistance to high dynamic loads. The traditional reinforced concrete on the impact side absorbs a major fraction of the energy of impact. On the back side (protection side), tensile forces are generated by the impact, which can excellently be handled by the UHPFRC/UHPFRSC. For proof of concept of the hybrid strengthening method, tests were carried out on UHPFRC - RC composite elements. In the test campaign, ballistic tests were performed using test specimens with dimensions of 500 × 500 mm. The layer thicknesses were 120 mm reinforced concrete and 40 mm UHPFRC. Additional steel rebars in the UHPFRC layer were applied for half of the specimens. The investigation demonstrated the effectiveness of the strengthening method, showing high resistance to high-dynamic loads. This behavior is attributed to the absorption and transfer of tensile stresses by the UHPFRC, that reduces penetration depth and damage, ensuring remaining load-bearing capacity after gunfire.

Optical coherence measurement-based penetration depth monitoring of stainless steel sheets in laser lap welding using long short-term memory network

The industrial production site for laser lap welding of thin stainless steel plates puts strict requests on the level and fluctuation stability of penetration depth. Hence, the penetration depth monitoring is increasingly garnering attention. This research proposes an optical coherence measurement-based approach to monitor penetration depth utilizing machine learning in laser lap welding for stainless steel sheets. After the acquisition of the keyhole depth signal by the coherent light beam, it is found that there is a significant association relationship between the reconstructed keyhole depth obtained by empirical modal decomposition and the penetration depth curve, but meanwhile a penetration depth monitoring error also exists. Accordingly, based on the cross-correlation analysis and numerical simulation, it is revealed that the formation mechanism and sources of this error are related to the “bottom melt layer thickness”, “hysteresis property” and “multiple reflections”. On this basis, a long short-term memory network is built to memorize the historical information of the reconstructed keyhole depth for predicting the penetration depth at each moment. The experimental results demonstrate that the prediction model has high accuracy and good generalization ability, and thus effective monitoring for penetration depth can be achieved.

Evidence for vertical line nodes in Sr2RuO4 from nonlocal electrodynamics

By determining the superconducting lower and upper critical fields Hc1(T) and Hc2(T), respectively, in a high-purity spherical Sr2RuO4 sample via ac-susceptibility measurements, we obtain the temperature dependence of the coherence length ξ and the penetration depth λ down to 0.04Tc. Given the high sample quality, the observed T2 dependence of λ at low temperatures cannot be explained in terms of impurity effects. Instead, we argue that the weak type-II superconductor Sr2RuO4 has to be treated in the nonlocal limit. By comparing our data with existing theory in that limit, the penetration depth in Sr2RuO4 agrees with a gap structure having vertical line nodes, while horizontal line nodes cannot account for the observation. The work highlights the potential benefits of purifying other unconventional superconductors in order to access the fascinating nonlocal regime in more materials and to determine their Cooper pair wave functions. Published by the American Physical Society 2024

Numerical simulation of heat transfer properties of skin tissue acted on repetitive laser irradiation

Pulsed laser has been widely used in the clinical treatment of various diseases and injuries due to its unique advantages in the process of interaction with skin tissue. In order to ensure the therapeutic effect and patient safety, it is necessary to accurately monitor the time-space response of the whole-field temperature of the target tissue irradiated by pulsed laser. A research strategy to explore the thermal response and incidental thermal damage of skin tissue induced by repeated pulses laser has been proposed in present work. A theoretical model involved variable physical properties was first proposed, in which the dual-phase lag (DPL) equation and Henrique burn equation were employed to evaluate the tissue temperature and thermal damage induced by repeated pulse laser irradiation. With the help of finite difference method, the governing equation with variable physical properties was then numerical solved to obtain the time-space distribution of tissue temperature, and the evolution process of the thermal damage was further calculated. The effects of laser input parameters and variable physical parameters on the laser penetration depth, temperature distribution and burn degree of the irradiated tissue were analyzed.

A new non‐equilibrium modification of the k−ω$$ k-\omega $$ turbulence model for supersonic turbulent flows with transverse jet

AbstractThe goal of this research is to propose a new modification of a non‐equilibrium effect in the turbulence model to better predict high‐speed turbulent flows. For that, the two local compressibility coefficients are included in the balance production/dissipation terms in a specific dissipation rate equation. The specific dissipation rate reacts to changes in the local Mach number and density through these local coefficients. The developed model is applied to the numerical simulation of the spatial supersonic turbulent airflow with round hydrogen injection. In that, the effects of the proposed turbulence model on the flow field behavior (shock wave and vortex formations, shock wave/boundary layer interaction, and mixture layer) are studied via the solution of three‐dimensional Favre‐averaged Navier–Stokes equations with a third‐order Essentially Non‐Oscillatory scheme. A series of numerical experiments are performed, in which an allowable range of local constants by comparing results with experimental data is obtained. The non‐equilibrium modification by simultaneous decrease of the turbulence kinetic energy and increase of the specific dissipation rate gives a good agreement of the hydrogen depth penetration with experimental data. Also, the numerical experiment of the supersonic airflow with a nitrogen jet shows wall pressure distribution is consistent well with experimental data.

Development of a localized surface plasmon-enhanced electron beam-pumped nanoscale light source for electron beam excitation-assisted optical microscopy.

We have demonstrated localized surface plasmon (LSP)-enhanced cathodoluminescence (CL) from an atomic layer deposition (ALD)-grown Al2O3/ZnO/Al2O3 heterostructure to develop a bright nanometer-scale light source for an electron beam excitation-assisted (EXA) optical microscope. Three types of metals, Ag, Al, and Au, were compared, and an 181-fold enhancement of CL emission was achieved with Ag nanoparticles (NPs), with the plasmon resonance wavelength close to the emission wavelength energy of ZnO. The enhanced emission is plausibly attributed to LSP/exciton coupling. However, it is also attributed to an increase in coupling efficiency with penetration depth and also to an increase in light extraction efficiency by grading the refractive indices at the heterostructure.

Performance Analysis of Pile Group Installation in Saturated Clay

In offshore pile engineering, the installation of jacked piles generates compaction effects within soil, thus further affecting previously installed adjacent piles. This study proposes a three-dimensional numerical model for pile group installation, soil consolidation, and loading analysis. Subsequently, the effect of pile spacing and pile length-to-diameter ratio on the deformation, internal forces, and vertical bearing capacity of adjacent piles are investigated. The results indicate that with an increase in pile center distance, the peak lateral displacement of the adjacent piles decreases, whereas the peak vertical displacement increases. As the pile length-to-diameter ratio increases, the peak vertical and lateral displacements of the adjacent piles are enhanced. In addition, the peak axial force of the adjacent piles initially decreases and then increases with the penetration depth of the subsequent pile, whereas the peak bending moment initially increases and then decreases. The vertical bearing capacity of the subsequent pile is significantly superior to that of the adjacent piles. Therefore, the effects of pile installation on adjacent piles should be included in pile engineering. The impact of the subsequent pile installation on the bearing capacity of adjacent piles can be significantly reduced by increasing the pile center distance and pile length-to-diameter ratio. The findings provide useful guidance for pile group engineering.

Design a metamaterial based applicator for hyperthermia cancer treatment

This research describes a metamaterial-based applicator with and without water bolus for cancer treatment. The metamaterial based applicator consists of a double spiral antenna and a slotted square shape artificial magnetic conductor (SSA) structure. The antenna is designed on a low-cost FR4 substrate with dimensions of 32 × 32 × 3.27 mm3, and the SSA unit cell which behaves as a metamaterial, is designed on an RT-duroid substrate with dimensions of 15 × 15 × 0.76 mm3 (size of the unit cell). The 4 × 4 unit cells of the SSA structure are optimized to direct the maximum field toward the cancer tissue. The proposed applicator (antenna + SSA structure) is tested for hyperthermia treatment using a heterogeneous phantom (skin, fat, and muscle layers) and the human-mimicked model with an air medium and a water bolus layer. The applicator’s performance is evaluated in terms of specific absorption rate (SAR), penetration depth (PD), and effective field size (EFS). Further, thermal analysis is performed, with 1.5 W of input power at the antenna port, and the maximum temperature rise of 44 0C is obtained. The cancer tissue (tumor) temperature ranges between 41 °C to 45 °C, sufficient for effective hyperthermia therapy. Finally, the suggested metamaterial based applicator is built and tested in the presence of a phantom and head tissue simulating liquid.

Experimental study on the effect of hydrate saturation in reservoir on microwave heating hydrate decomposition gas production

Microwave heating technology is an effective method to promote the decomposition of hydrates, with hydrate saturation being an important parameter influencing this process. This study has synthesized natural gas hydrates with different saturations within a high-pressure reaction vessel to conduct experiments on the decomposition of natural gas hydrates by microwave heating. The reservoir temperature, gas production dynamics, and energy utilization rate are investigated for hydrate saturations of 30.26 %, 35.63 %, and 39.61 %, respectively. The results indicate that increasing hydrate saturation enhances the microwave penetration depth, which in turn elevates the reservoir temperature and accelerates hydrate decomposition. When the hydrate saturation increases from 30.26 % to 39.61 %, the gas production time decreases. Simultaneously, both the volume and rate of gas production increase, accompanied by enhanced energy utilization rate. When the hydrate saturation is 39.61 %, the experiment achieves an average gas production rate of 1.17 L/min, a total volume of 19.73 L, and an energy utilization rate of 2.716. The research results can promote the application of microwave heating technology in the development of hydrates.

Microvascular flow imaging of fibroids: A prospective pilot study.

Imaging fibroid vascularity may predict fibroid growth and aid to determine most appropriate therapy. Microvascular (MV) flow imaging is relatively new and is able to detect slow flow in small vessels. Data on feasibility, reproducibility, and reliability of MV-flow imaging in fibroids is lacking. The purpose of our study was to determine the reproducibility of MV-flow imaging and to explore this technique for clinical practice for assessing blood flow in fibroids. Thirty patients with one or multiple fibroids (diameter 1.5-12.0 cm) were prospectively included. Transvaginal ultrasound scanning was performed in B-mode, 2D MV-Flow™, 2D and 3D power Doppler mode (HERA W10, Samsung) by two experienced gynecologists at a tertiary care clinic from February to December 2021. The primary outcome was intra- and interobserver agreement of the vascular index (VI) and color score (CS). The following parameters: '2D MV-flow VI', '3DPD VI', '2D MV-flow CS' and '2DPD CS' were measured offline in the center, pseudocapsule, and entire fibroid. Secondary offline outcomes for exploring 2D MV-flow for clinical practice, included (1) ability to discern vascular structures, (2) assessing the degree of vascularity via CS and calculating a VI, and (3) determining penetration depth of the ultrasound signal in both power Doppler and MV-flow imaging. All scans of the 30 included patients were of sufficient quality to analyze. Inter- and intra-observer correlations of all studied parameters were good to excellent, both for 2D MV-flow and 2D power Doppler (intercorrelation coefficient 0.992-0.996). Using 2D MV-flow different vascular structures were visible in detail, in contrary to using 2D and 3D power Doppler. In significantly more fibroids central flow could be visualized using 2D MV-flow (63%) than with 2D power Doppler (13%,p = 0.001). Finally, penetration of the ultrasound signal was deeper using 2D MV-flow (3.92 cm) than with 2D power Doppler (2.95 cm, p = 0.001). Using 2D MV-flow imaging for determining vascularity is highly reproducible. It has potential added value for clinical practice as it depicts detailed vascular structures and the degree of vascularity, especially in the center of the fibroid.

Inscription of Complex Stent Profiles on the Polished Surfaces of NiTiCo Shape Memory Alloys by Fiber Lasers: Examining the Impact of Diffuse Reflectance

Drug eluting stents (DES) have become essential to alleviate stenosis with minimally invasive procedures. Nickel-titanium (NiTi) based shape memory alloys (SMAs) are the most suitable materials for self-expanding stents due to their good stability and superior thermo-mechanical properties. This work explains the inscription of complex DES profiles by fiber laser micro-cutting (FLMC) on Nickel-Titanium-Cobalt (NiTiCo) SMA surfaces polished with various grits (1000P, 1500P, 2000P, 2500P, 3000P, and cloth polished) of abrasive sheets. The impact of the SMA surface diffuse reflectance on laser micromachining characteristics was investigated. The Fuzzy PROMETHEE II multi-criteria decision-making (FP II-MCDM) technique was employed to find the best-polished surface that provides the most desired responses (kerf quality, surface roughness, and depth of penetration) for clinical applications. The cloth-polished surface responds better in laser machining without compromising the kerf quality and surface roughness. A significant variation of 18% in kerf quality was found between the 3000P and the cloth-polished surfaces. This indicates that the surface diffuse reflectance has maximum impact when the surfaces are highly polished. For applications where surface roughness and kerf width are not a criterion, then polished surfaces between 1500P and 2000P give the maximum machining rate.

A DNA machine-based magnetic resonance imaging nanoprobe for in vivo microRNA detection

In situ monitoring microRNA (miRNA) expression in vivo holds immense potential for directly visualizing the occurrence and progression of tumors. However, the significant barrier to developing a probe that can overcome the low abundance of miRNAs while providing an output signal with unlimited tissue penetration depth remains formidable. In this study, we developed a DNA machine-based magnetic resonance imaging nanoprobe (MRINP) for amplified detection of miR-21 in vivo. The MRINP was constructed with superparamagnetic Fe3O4 nanoparticles (NPs), paramagnetic Gd-DOTA complexes, and miR-21-activated DNA machines; the DNA machine was composed of hairpin DNAzyme (HD) strands serving as the DNAzyme walker and hairpin substrate (HS) strands serving as the track. Once uptake into tumor cells, the intracellular miR-21 specifically recognized and hybridized with the HD strand, restoring the activity of DNAzyme. Subsequently, the DNAzyme walker autonomously traveled on the surface of MRINP, and each step movement of the DNAzyme walker resulted in the cleavage of its substrate strands and the ensued release of the Gd-DOTA complex-labeled oligonucleotides, turning on the T1 signal of Gd-DOTA complexes for in situ imaging of miR-21 in tumor-bearing mice. This strategy would offer a promising approach for mapping tumor-specific biomarkers in vivo with unlimited penetration depth.