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A global issue that requires attention is the duality between the shortage of needles for regular vaccination campaigns and the exponential increase in syringe and needle waste from such campaigns, which has been exacerbated by the COVID-19 pandemic. In response to this problem, this study presents a 3D printed needleless injector based on thermocavitation. The work focused on investigating the interaction of the resulting liquid jets with skin phantoms at different concentrations (1–2%), emphasizing their impact and penetration depth in a repetitive regime. The injector was designed and fabricated from a semi-transparent polymer using a high-resolution 3D printer, allowing the ejection of liquid jets with velocities up to ~ 73 m/s. The impact of these jets on skin phantoms was evaluated using a high-speed camera. After 6 consecutive liquid jets (1% concentration), a maximum penetration depth of ~ 2.5 mm was achieved, delivering approximately 4.7 µL. For the highest concentration (2.0%) and the same number of shots, the penetration depth was reduced to ~ 0.6 mm with a delivered volume of ~ 0.7 µL. An important finding of this study is that the liquid jet with the highest pressure does not cause the maximum penetration depth, but is the result of a series of successive shots. In addition, the velocity and shape of the ejected jet are determined by the amount of solution and the meniscus formed inside the injector. These findings advance the development of precise and efficient thermocavitation-based injectors with broad potential applications in medical and pharmaceutical fields. [ABSTRACT FROM AUTHOR]

In this work, two polycrystalline samples were prepared using the solid-state reaction technique. The X-ray diffraction patterns revealed that the samples A and B are a mixture of the superconducting phases (Bi, Pb)-2212 (Bi1.6Pb0.4Sr2CaCu2O8) and (Bi, Pb)-2223 (Bi1.6Pb0.4Sr2Ca2Cu3O10). The T c was measured using electron paramagnetic resonance (EPR) in absorption mode: 97 K for the sample A and 101 K for sample B. The EPR spectra were measured (derivative of the absorption) and showed a signal in the low-field region only present in the superconducting state. The study of this signal revealed the coexistence of antiferromagnetism and diamagnetism in the sample A, for T < T c . The same was observed in sample B after a light grinding. The effective penetration depth was estimated from the peak-to-peak linewidth of the EPR signal (at T = 92 K): λ (92 K) = 479 nm for sample A, and 440 nm for sample B. These results are in agreement with the values obtained using techniques such as μ -spin rotation and magnetization measurements. With the aid of the two-fluid model and the BCS approximation λ was also estimated at 0 K. Using these values and the Ginzburg-Landau theory, the lower critical field was calculated at T = 92 K and 0 K. [ABSTRACT FROM AUTHOR]

Background: Hyperthermic intrathoracic chemotherapy (HITOC) is an additive treatment option after surgical cytoreduction of pleural malignancies. Despite growing clinical experience and studies evaluating its feasibility, postoperative morbidity and mortality, as well as the effect on survival, there is still only little known about the local effects of HITOC on the lung parenchyma and tumour cells. The objective of this in vitro study was to evaluate the dose-dependent concentration and penetration depth of cisplatin in human lung tissue. Methods: In total, 40 patients were enrolled for elective lung resection, and wedge samples were taken to the laboratory. The visceral pleura was removed, and the decorticated lung tissue was incubated in cisplatin solutions of different concentrations (0.05, 0.075, and 0.1 mg/mL) at 42 °C over 60 min. Afterwards, platinum amounts in the lung tissue samples were measured using atomic absorption spectroscopy. Results: A strong decline of the cisplatin concentration was found until a depth of 3.5 mm, followed by a mild decline until a depth of 7.5 mm. In a depth of 0.5 mm, there was only a significant difference between 0.05 and 0.1 mg/mL (p = 0.03, Cohen's d = 0.43). In a depth of 1.5 mm, there was an overall significant difference in cisplatin concentration dependent on dose (p = 0.027). In deeper tissue layers, no significant difference in cisplatin concentrations in the tissue was found. Conclusions: A dose-dependent increase of the cisplatin concentration was found for superficial tissue layers. This emphasises the relevance of sufficiently high intrathoracic concentrations of the chemotherapeutic agent. This study confirms that cisplatin penetrates lung tissue in therapeutically effective concentrations. [ABSTRACT FROM AUTHOR]

Numerical investigations are conducted to examine the penetration depth of ellipsoid-shaped projectiles into semi-infinite aluminum targets under conditions of hypervelocity impact. These results are then compared against empirical equations developed by various researchers for spherical projectiles. The semi-infinite aluminum target, sized at 1 5 0 × 1 5 0 × 5 0 mm, is composed of Al7075-T651. The projectiles are fashioned from Al-7075-T651, steel, and boron carbide. The projectile's shape factor was determined using the L/d ratio, specifically for the symmetrical ellipsoidal shape. Employing Ansys Autodyn, a 3-dimensional finite element model (FEM) is created and calibrated using existing experimental findings from the literature. The validation utilized the Johnson–Cook (JC) and Johnson–Holmquist (JH-2) material models for both the targets and projectiles. These validated models are subsequently employed to analyze how the ellipsoid projectile's shape and density influenced their interaction with the semi-infinite targets. Furthermore, the investigation also encompassed an analysis of the resulting crater shapes generated by the hypervelocity impact of both metallic and nonmetallic projectiles. It is observed that for a definite SF, max m depth of penetration is observed due to steel project as compared to boron carbide and aluminum projectile. Both the diameter of the crater and the height of the bulge ( H c) are directly proportional to the impact velocity and density of projectiles, and inversely proportional to SF. However, for a particular material and impact velocity of the projectile, in the case of H c , there are no clear-cut observations displayed it seems like a mixed variation. [ABSTRACT FROM AUTHOR]

This study examines the influence of nanofillers on the ultraviolet (UV) penetration depth of photopolymer resins used in stereolithography (SLA) 3D printing, and their impact on printability. Three nanofillers, multiwalled carbon nanotubes (MWCNT), graphene nanoplatelets (xGNP), and boron nitride nanoparticles (BNNP), were incorporated into a commercially available photopolymer resin to prepare nanocomposite formulations. The UV penetration depth (Dp) was assessed using the Windowpane method, revealing a significant reduction with the addition of nanofillers. At a concentration of 0.25 wt.%, MWCNT showed the highest reduction in Dp (90%), followed by xGNP (65%) and BNNP (33%). SLA 3D printing was performed at varying nanofiller concentrations to evaluate printability. The findings highlight a strong correlation between Dp and the maximum printable nanofiller concentration, with MWCNT limiting printability to 0.05 wt.% due to its low Dp, while BNNP allowed printing up to 1.5 wt.%. Mechanical testing showed substantial improvements in hardness and elastic modulus, even at low nanofiller concentrations, with BNNP outperforming other fillers. Compared to a clear photopolymer, the elastic modulus for 3D printed nanocomposite samples with 0.05 wt.% nanofiller compositions showed an improvement of 43% for MWCNT, 63% for xGNP, and 104% for BNNP. The hardness results showed an improvement of 86% for MWCNT, 103% for xGNP, and 179% for BNNP. These results underscore the importance of Dp in determining the layer thickness and print success in SLA 3D printing. Practical applications include the design of advanced photopolymer nanocomposites for biomedical devices, electronics, and lightweight structural components. This research provides valuable insights for tailoring material properties to meet the demands of high-performance additive manufacturing. [ABSTRACT FROM AUTHOR]

Joyce Liu School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, 14642, USACorrespondence: Joyce Liu, School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, 14642, USA, Email joyce_liu@urmc.rochester.eduPurpose: Laser surgery can use photo-chemical, photo-thermal, photo-ablative, and photo-mechanical effects to treat various tissues in the human body, and has unique advantages of extremely high precision, non-invasive penetration, and fast operation speed. However, at present, the effective penetration depth of directly illuminating light in the body is only several millimeters. Therefore, increasing the safe operating depth for non-invasive laser surgery will have important, widespread, and irreplaceable applications in the future.Methods: The method is based on improving a recently emerged technique. Its principle involves using a negative dispersion device to broaden the width of the short light pulse first. Then, after the pulse enters the body, as its peak intensity is reduced, the skin and healthy tissues in the laser propagation path cannot be injured. Meanwhile, since body tissues have positive dispersion, the broadened width of the laser pulse will be shortened back. When the broadened pulse is completely shortened, a thin inner light layer with high intensity will be formed in the body and used as a scalpel to treat target tissue.Results: The theoretical calculation results have shown that the designed apparatus has excellent performance. Its safe non-invasive operating depth can be more than 70 millimeters with the possibility of up to 130 millimeters. Surgery precisions are around 1 micron transversely and about 1 millimeter longitudinally in theory.Conclusion: An improved method of non-invasive laser surgery with deep operation depth has been investigated theoretically. The calculations show that the designed apparatus has excellent performance. The proposed method depends on two well-known physical phenomena: light pulse broadening and shortening caused by optical negative and positive dispersions, and thus has solid basis. The developed method will have important, widespread and irreplaceable applications in the medical surgery field.Keywords: absorption, scattering, negative dispersion fiber, penetration depth

Functional near infrared spectroscopy (fNIRS) is being increasingly used to assess brain hemodynamic responses during active walking in older adults due to its wearability, and relative immunity to motion artifacts. Specifically, fNIRS allows for continuous monitoring of brain activations that vary in response to experimental manipulations of cognitive demands during active walking tasks. Studies using fNIRS highlighted increased involvement of the prefrontal cortex (PFC) in dual compared to single task walking, operationalized using oxygenated hemoglobin (HbO), due to increasing attention demands inherent in the former task condition in aging and clinical populations. However, current literature utilizing fNIRS in mobility research has not been uniform in terms of fNIRS instrumentation characteristics and the accompanying signal processing methods to separate various signal sources (i.e. neural activations, extracerebral signals, systemic responses) which can raise questions about prior research findings. In our previous studies, we have used a forehead fNIR sensor (fNIR Imager 1100 by fNIR Devices, LLC) with 2.5 cm source detector separation (SDS) at 2 Hz sampling rate which allowed us to reliably evaluate changes in brain activations in the PFC during active walking. However, there exists other fNIRS devices incorporating a number of different types of light sources and detectors allowing multiple channels of long (3 cm SDS) and short (0.8 cm SDS) distance measurements in complex configurations for the monitoring of cognitive activations on various head locations at different depths with higher sampling rates of ~5 Hz (i.e. NIRx sensor, NIR Sport2 by NIRx Medizintechnik GmbH). Such involved designs further allowed the implementation of advanced signal processing algorithms to separate and evaluate neural, systemic and extracerebral signal contributions on the overall measurements. In this study, we collected brain imaging data on a sample of healthy older adults (n =15, age $\ge 60$ ) under single (STW) and dual task walking (DTW) conditions; participants were evaluated twice during one study visit, once wearing fNIR sensor and a second time while wearing NIRx sensor. This study design allowed us to address critical gaps in the extant literature concerning fNIRS-derived brain activations during active walking. Specifically, we evaluated potential effects of penetration depth as defined by the SDS of the fNIRS device, extracerebral activations (i.e. skin blood flow) and systemic signals (i.e. heart rate) on the observed HbO increases from STW to DTW. Our findings suggested that PFC activation differences between STW and DTW conditions observed in older adults were consistent across fNIRS instrumentations and the observed differences in HbO between STW and DTW were not materially influenced by scalp activations or systemic changes. Nevertheless, efforts to optimize extraction of fNIRS-derived brain signal measurements should continue taking advantage of technological advancement.

Multi-component ultra-high-temperature ceramics (MC-UHTCs) are promising for high-temperature applications due to exceptional thermo-mechanical properties, yet their wear characteristics remain unexplored. Herein, the wear behavior of binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs synthesized via spark plasma sintering (SPS) is investigated. Gradual addition of equimolar UHTC components improves the wear resistance of MC-UHTCs, respectively, by ~29% in ternary UHTCs and ~49% in quaternary UHTCs when compared to binary UHTCs. Similarly, the penetration depth decreased from 115.14 mm in binary UHTCs to 73.48 mm in ternary UHTCs and 44.41 mm in quaternary UHTCs. This has been attributed to the complete solid solutioning, near-full densification and higher hardness (~up to 30%) in quaternary UHTCs. Analysis of the worn-out surface suggests pull-out, radial, and edge micro-cracking and delamination as the dominant wear mechanisms in binary and ternary UHTCs. However, grain deformation and minor delamination are the dominant wear mechanisms in quaternary UHTCs. This study underscores the potential of MC-UHTCs for tribological applications where material experiences removal and inelastic deformation under high mechanical loading.

Objectives: Pit and fissure sealants provide a protective barrier against microbial infiltration and plaque accumulation, effectively reducing the risk of occlusal caries. However, microleakage remains a significant challenge, influencing sealant efficacy. This study evaluates and compares the penetration depth and microleakage of hydrophilic sealants and flowable composites under in vitro conditions. Methods: Twenty extracted third molars with deep pits and fissures were randomly divided into two groups. Acid etching was performed using 37% orthophosphoric acid, followed by the application of either a hydrophilic sealant or a flowable composite. Samples were immersed in 1% Methylene blue dye for 24 hours to assess microleakage. After sectioning, penetration depth was measured using a stereo-microscope. Statistical analysis was conducted using SPSS software (Version 20.0, IBM Corp, Armonk, NY, USA) with the Mann-Whitney U test. Results: The hydrophilic sealant group exhibited significantly lower dye penetration and higher penetration depth percentages compared to the flowable composite group, indicating superior sealing properties and adaptability. Conclusion: Hydrophilic sealants demonstrated better performance in terms of reduced microleakage and enhanced penetration depth compared to flowable composites, making them a promising choice for fissure sealing, particularly in conditions with moisture challenges. Further studies are recommended to confirm these findings and assess long-term clinical performance.. [ABSTRACT FROM AUTHOR]

A D-shaped fiber optic plasmonic refractive index sensor with sinusoidal corrugation is proposed. Proposed structure is analyzed for different refractive indices of the sample at the optimized corrugation parameters. Electric field is confined to core and further coupled to metallic sinusoidal corrugation for the sample refractive ≥ 1.37. However, proper dip of the transmittance curve is achieved for the sample refractive ≥ 1.38. It is seen that the resonance wavelength, shift in resonance wavelength, bandwidth, and penetration depth of field in the sample increase whereas minimum transmittance and propagation length reduce by increasing the refractive index of the sample beyond 1.37. Further, the proposed sensor localizes the penetration depth in the sample near to 150 nm and propagation length at the metal-sample interface near to 5 µm. The proposed sensor can be used in the event of specific detection of smaller biomolecules by tuning the corrugation parameters. [ABSTRACT FROM AUTHOR]

This study focuses on achieving enhanced mechanical properties of the welded joints, which is critical for the applications of mild steel (MS) plates in various industries. In this regard, a systematic approach is used to adjust welding parameters such as welding current and workpiece thickness in shielded metal arc welding (SMAW), with the objective of identifying the optimal combination that maximizes weld quality. The experiments were planned with the help of Taguchi's L9 orthogonal array method in order to reduce experimental cost and time. The weld quality is optimized by determining the signal-to-noise ratios of weld penetration, tensile strength, impact strength, and microhardness for each experimental sample. As a result, 110 A welding current is obtained as the optimal SMAW parameter for a 5 mm thick MS IS 2062 Grade B plate. This optimized result has also achieved 394.78 N/mm2 tensile strength and 53 J of impact resistance for the respective specimen. Besides, research not only enhances understanding of the SMAW process but also offers practical implications for industries requiring high-performance welded joints in MS structures. Additionally, this study can assist upcoming researchers in optimizing any existing welding procedures. [ABSTRACT FROM AUTHOR]

Multi-component ultra-high-temperature ceramics (MC-UHTCs) are promising for high-temperature applications due to exceptional thermo-mechanical properties, yet their wear characteristics remain unexplored. Herein, the wear behavior of binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs synthesized via spark plasma sintering (SPS) is investigated. Gradual addition of equimolar UHTC components improves the wear resistance of MC-UHTCs, respectively, by ~29% in ternary UHTCs and ~49% in quaternary UHTCs when compared to binary UHTCs. Similarly, the penetration depth decreased from 115.14 mm in binary UHTCs to 73.48 mm in ternary UHTCs and 44.41 mm in quaternary UHTCs. This has been attributed to the complete solid solutioning, near-full densification and higher hardness (~up to 30%) in quaternary UHTCs. Analysis of the worn-out surface suggests pull-out, radial, and edge micro-cracking and delamination as the dominant wear mechanisms in binary and ternary UHTCs. However, grain deformation and minor delamination are the dominant wear mechanisms in quaternary UHTCs. This study underscores the potential of MC-UHTCs for tribological applications where material experiences removal and inelastic deformation under high mechanical loading. [ABSTRACT FROM AUTHOR]

Offshore piles are widely used as support and anchoring structures to provide stable support foundations. In this study, a novel torpedo pile is designed that combines water-jet technology and vibration loading to disturb/fluidize the cohesive sediments around the torpedo pile, reduce the resistance between the torpedo pile and cohesive sediments, and increase the efficiency of pile penetration and extraction. Experiments were conducted to investigate the characteristics of pile penetration and extraction in water-jet and vibration loading scenarios. The results indicated that the combined vibration and water jet method significantly reduced the resistance of the cohesive sediment to the torpedo pile during the pile penetration process, and the pile penetration speed increased as the water-jet pressure increased. The extraction efficiency of the torpedo pile was most significantly improved under the combined vibration and water jet method, and the maximum extraction force of the pile was reduced by approximately 78.2%. [ABSTRACT FROM AUTHOR]

This contribution focuses on the spatial‐temporal behavior and reactive pathways of O3 produced by a surface air microdischarge in the gas and liquid phase using ultraviolet absorption spectroscopy. The findings demonstrate that mode transition from ozone to nitrogen oxide over time is observed at a constant input power higher than ~0.60 W/cm2. Due to the long‐lived characteristic and ionic wind, the perpendicular distribution of O3 is almost uniform. The maximum penetration depth is around 5 mm, and the gas–liquid mass transfer efficiency is approximately 0.4‱ at a depth of 1 mm, when the treatment time is 10 min. The mass transfer of O3 between gas and liquid phases is dominated by the liquid convention induced by ionic wind. [ABSTRACT FROM AUTHOR]

In this paper, a TMDC-based surface plasmon resonance (SPR) sensor for detecting fat concentration milk, incorporating an Ag-Pt (bimetallic) layer, is presented. The Pt (Platinum) layer provides chemical stability and increases sensitivity with the TMDC layer. Compared to the conventional SPR sensor, the maximum sensitivity, detection accuracy (DA), and figure of merit (FoM) of 314∘/RIU, 0.142/degree, and FoM 44.05/RIU are achieved with the WS2 layer. The sensor's increased sensitivity is due to the increased field intensity and depth of penetration into the sensor layer, resulting in a larger interaction volume. The presence of the WS2 layer, with its significant imaginary part of the dielectric constant, helps improve sensitivity and broadens the SPR curves. This broadening SPR curve ultimately affects the DA and FoM of the sensor. The capability of the proposed sensor to detect various biological analytes with a refractive index (1.3452–1.3657) can be demonstrated. [ABSTRACT FROM AUTHOR]

Transdermal drug delivery using dissolving microneedles (DMNs) is promising due to increased patient compliance and safety. This article presents a comprehensive simulation and experimental analysis of DMNs with varying tip and base diameters and polymers. The objective of the simulation study is to identify the optimal tip and base diameter of DMNs, as well as the most suitable polymer, for achieving maximum penetration depth. The simulation results showed that the compound consisting of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) in a ratio of 2:1, with a tip radius of 17.5 μm and a base radius of 150 μm, achieved the deepest penetration among the different types of polymers investigated (including PVA, hyaluronic acid (HA), and PVA/PVP in ratios of 1:1 and 1:2). In addition, mechanical and skin penetration experiments were performed on PVA/PVP 2:1 DMNs with varying concentrations of 4, 7, 10, and 15% w/w to determine the optimal polymer concentration. The results of this study indicated that the optimal composition, considering the viscosity of the polymer solution and the simplicity of filling the silicone negative molds, is a PVA/PVP 2:1 with a concentration of 7% w/w. [ABSTRACT FROM AUTHOR]

This study explores the surface plasmon resonance (SPR) and the electromagnetic field responses of multi-layer structures with incident light to enhance the sensitivity and range for measurement of nanoscale thin liquid film thickness. We assess the effect of metal layer type and its corresponding thickness on the optical responses. Notably, the silver (Ag) layer exhibits a more acute reflectance curve with a thickness of 50 nm, which is attributable to the minimization of non-radiative losses and a substantial real component of the dielectric constant of the Ag layer. Furthermore, a correlation between liquid film thickness and reflectance has been established across different metal layer types at specified thicknesses. The Ag layer demonstrates the broadest measurement range for liquid film thickness due to its extensive penetration depth into the dielectric material. Conversely, the sodium (Na) layer presents the narrowest measurement range, albeit with the highest SPR sensitivity. [ABSTRACT FROM AUTHOR]

Demineralization is the result of a pH imbalance process that leads to the dissolution of hydroxyapatite crystals with the loss of calcium phosphate and other ions in the tooth structure. To restore the minerals lost during the demineralization process, saliva works naturally through a selfcleansing mechanism by producing the calcium and phosphate needed for remineralization. However, if demineralization continues, additional remineralization agents are needed to protect the tooth enamel from further mineral loss and damage. The purpose of this study was to analyze penetration depth ability of three remineralization agents as fluoride varnish, calcium phosphate paste (CPP-ACP), and calcium phosphate paste with fluoride (CPP-ACPF) on enamel. This research was true experimental study invitro with 24 samples of maxilla premolars that divided into four groups, 6 samples each group. Group 1 was given an application of fluoride varnish, group II was given an application of CPP-ACP, group III was given an application of CPP-ACPF, and Group IV as a control without application remineralization agents. Each tooth sample was cut in the buccal palatal direction after being given remineralization material for 14 days. Penetration depth of remineralization agent was measured by scanning electron microscope (SEM). Data normality test was performed on each sample, then the analysis will be carried out using one-way analysis of variance (ANOVA) followed by post-hoc analysis of the Independent t-test. Fluoride Varnish showed average penetration depth of 51.15 ± 34.35 μm, and CPP-ACP 41.95 ± 9.87 μm. CPP-ACPF showed the highest average penetration depth of 75.88 ± 43.77 μm. The addition of fluoride to calcium phosphate paste increases the effectiveness of remineralization penetration in enamel which can have important implications in preventing demineralization. There was a significance difference in penetration depth of three remineralization agent; Fluoride varnish, Calcium phosphate paste (CPP-ACP) and Calcium Phosphate with Fluoride (CPP-ACPF) on Enamel. Calcium phosphate with fluoride had the highest penetration depth ability and most effective as remineralization agent. [ABSTRACT FROM AUTHOR]

Techniques for measuring the soil moisture content (SMC) using global navigation satellite system-interferometric reflectometry (GNSS-IR) with a positioning antenna have been reported. However, conventional methods are limited to evaluating the relative change in volumetric water content in a dry range for certain soil textures. In this study, we proposed a method to measure relative permittivity using GNSS-IR and evaluated its applicability at two sites with different soil textures and moisture content. The true multipath penetration depth was obtained from the tangent dielectric suitable for the soil textures, and the apparent penetration depth affected by the relative permittivity of the soil was calculated from the signal-to-noise ratio measured by GNSS. The relative permittivity of the soil was obtained from the ratio of these values and compared with the relative permittivity of the SMC sensor. As a result, we could measure soil permittivity according to soil textures from dry to wet conditions from GNSS-IR, except when the true multipath wave penetration depth was less than 1.5 cm, at which only surface reflection occurred. Sandy soils with a low dielectric loss tangent and wet areas with small changes in the depth of penetration of electromagnetic waves are particularly suitable environments for this method. [ABSTRACT FROM AUTHOR]

Seafloor landing research is crucial for underwater robots tasked with long-term fixed-point observation missions, particularly those requiring prolonged operations on the seabed. Developing safe and stable landing technology is essential for the success of these missions. This paper introduces a novel underwater robot by establishing its dynamic model and using the arbitrary Lagrangian–Eulerian (ALE) method to conduct a comprehensive study of its deep-sea landing process. Prior to detailed parameter analysis, the ALE algorithm's effectiveness and accuracy were validated through experimental data and simulation results from previous studies. This study examines the penetration depth and force conditions during the landing process by varying factors such as seabed soil properties, landing velocity, and the robot's mass. Findings indicate that seabed soil properties significantly influence penetration depth and pressure, with variations in soil density and strength affecting the robot's landing behavior. In contrast, the robot's mass has a relatively minor effect, suggesting that the choice of structural materials has limited impact on penetration depth and pressure during landing. Additionally, landing velocity was found to significantly affect penetration depth and pressure; higher velocities result in greater penetration depths and pressures. This highlights the importance of controlling landing velocity to minimize impact forces and protect the robot. The results of this study provide theoretical support and data for developing deep-sea landing technology for novel underwater robots and inform the selection of structural materials, ensuring the successful execution of long-term fixed-point observation missions in deep-sea environments. [ABSTRACT FROM AUTHOR]

Presented in this paper is an evaluation of human tissue penetration by millimeter wave (mmW) energy, particularly at 30, 35, 40 and 45 GHz. Numerical simulations show that the penetration depths in the tissue are (0.1000, 0.0937, 0.08869 and 0.08882) mm at the aforementioned frequency, respectively. It is also demonstrated that all mmW at those frequencies attenuate to zero at the epidermis which is the layer adjacent to the skin surface, without getting into the dermis which is the next layer. Crucially, these discoveries present fresh, previously unmentioned data within the current research literature. Furthermore, at the lower frequency of 24 GHz, computer simulations presented show that the propagating wave penetrates deeper (depth of 0.12 mm) and attenuates to zero at the dermis. This shows that the depth of penetration increases further at lower frequencies which strongly conforms to the principles of physical reasoning, thereby bolstering the reliability of the findings presented in this paper. The results collectively indicate that the absorption of mmW into the human tissue have limited significance when assessing compliance with electromagnetic field standards at mmW frequencies. It is reinforced in this paper why the human skin reduces the harmful effects of ultra-violet radiation. To lend credence to our formulation, certain aspects of the results obtained in this investigation when compared with similar results in the literature, show good agreements.

In this study, an innovative approach has been employed to evaluate the cladding performance characteristics of medium carbon steel using super duplex stainless steel filler material. This research explores the effect of welding current, gas flow rate, and welding speed on key performance indicators such as hardness, corrosion rate, bead width, and penetration depth. The maximum hardness of 137.4 Hv, maximum bead width of 6.728 mm, maximum penetration of 2.016mm and minimum corrosion rate of 26.25 x 10-3 mils/year were observed in proposed sample. The primary objective is to establish the empirical relationship between dependent and independent variables to identify the optimal parameters for cladding process. To accomplish this, the RSM and GA optimization has been utilized for modeling and optimization, respectively. The regression models are subjected to GA optimization to identify the best dependent and independent variables were 84.95A current, 7.12 lpm gas flow rate and 74.42 mm/min weld speed. The findings demonstrate that the predicted empirical model output the experimental values validating our approach. In addition the cladding process delivers a significant contribution in the field of welding and provides valuable insights into this process. The SEM & OM analysis was carried out for optimized sample which microstructure is fine-grained also desirable for good weld quality. [ABSTRACT FROM AUTHOR]

Presented in this paper is an evaluation of human tissue penetration by millimeter wave (mmW) energy, particularly at 30, 35, 40 and 45 GHz. Numerical simulations show that the penetration depths in the tissue are (0.1000, 0.0937, 0.08869 and 0.08882) mm at the aforementioned frequency, respectively. It is also demonstrated that all mmW at those frequencies attenuate to zero at the epidermis which is the layer adjacent to the skin surface, without getting into the dermis which is the next layer. Crucially, these discoveries present fresh, previously unmentioned data within the current research literature. Furthermore, at the lower frequency of 24 GHz, computer simulations presented show that the propagating wave penetrates deeper (depth of 0.12 mm) and attenuates to zero at the dermis. This shows that the depth of penetration increases further at lower frequencies which strongly conforms to the principles of physical reasoning, thereby bolstering the reliability of the findings presented in this paper. The results collectively indicate that the absorption of mmW into the human tissue have limited significance when assessing compliance with electromagnetic field standards at mmW frequencies. It is reinforced in this paper why the human skin reduces the harmful effects of ultra-violet radiation. To lend credence to our formulation, certain aspects of the results obtained in this investigation when compared with similar results in the literature, show good agreements. [ABSTRACT FROM AUTHOR]

This study aimed to determine the infrared (IR) spectra of the main optical properties of poly(methyl methacrylate) (PMMA). This is a simple and original method for obtaining spectra of the main optical properties from the reflection–absorption spectrum. Infrared reflection spectra of the main optical properties of PMMA were obtained from the complex relative permittivity using the Drude–Lorentz model for permittivity. Classical dispersion analysis of the reflection–absorption spectrum of poly(methyl methacrylate) films cast on a metal mirror was performed. The method is based on an iterative least squares fitting process of the experimental reflection–absorption spectrum of the polymer with the corresponding theoretical spectrum obtained from the complex permittivity Drude–Lorentz model. This approach is original for obtaining the relative permittivity and subsequently obtaining the main optical properties of the polymer film: complex electric modulus, energy loss function, optical constants, absorption coefficient, penetration depth, dissipation factor, and complex optical conductivity. In addition to the findings of other articles, some optical properties of PMMA films have been presented, which may be useful for studying PMMA-based composites or copolymers. Please confirm if the author names are presented accurately and in the correct sequence Author 1 Given name: [Maria Laura ] Last name [Strugariu]. Author 2 Given name: Sorina Gabriela Last name [Șerban] Author 3 Given name: [Antonia Maria ]Last name :[Berdie] Also, kindly confirm the details in the metadata are correct.Yes [ABSTRACT FROM AUTHOR]

The strength of cast-in-place concrete is obtained using the innovative pendulum hammering test method (PHTM) to reduce structural damage to concrete. A specially developed PHTM device is used to apply a fixed impact force to nails and determine the relationship between the penetration depth of nails and the compressive strength of the concrete. Adverse factors such as aggregate type and concrete moisture content on concrete strength were eliminated and their impact on PHTM test results was avoided. The compressive strength of the tested concrete cube samples ranges from 20 to 50 MPa. The reliability and repeatability of PHTM are superior to the Schmidt hammer (SRH) and pull-out testing methods used in on-site testing. Research has confirmed that PHTM is suitable for in situ testing of prefabricated buildings, beam column joints, and other densely reinforced areas, and unsuitable for coring. Compared with other testing methods, PHTM testing has high accuracy and minimal damage to concrete structures. [ABSTRACT FROM AUTHOR]

The present work focuses on the detection of dengue virus using a proposed copper (Cu) and black phosphorus (BP)–based SPR sensor. This proposed sensor is capable of detecting normal and infected blood samples containing plasma, platelets and hemoglobin. We studied the performance parameter at optimized Cu layer thickness of the proposed sensor by calculating that the maximum sensitivity is 150.55°/RIU, 226.73°/RIU and 295.58°/RIU at Rmin values with 57 nm, 57 nm and 51 nm thickness of Cu layer for the detection of plasma, platelet and hemoglobin in the blood sample of dengue malaria. The properties of BP combined with the unique plasmonic properties of SPR sensors can result in enhanced interactions between surface plasmons and incident light. These results are intended for improved sensitivity and remarkable figure of merit (FoM). We also calculated the electric field and penetration depth (PD) for the same sample. In this study, the normal and infected blood samples are successfully examined for the performance parameters for the plasma, platelets and hemoglobin. [ABSTRACT FROM AUTHOR]

SARS-CoV-2 causes COVID-19, a global health crisis with diverse symptoms, posing diagnostic challenges. The scarcity of testing equipment leads to long wait times for COVID-19 tests. To address this challenge, we propose a surface plasmon resonance biosensor configured as: Prism (BK7)/Copper (Cu)/Nickle (Ni)/graphene. This configuration proves advantageous for the detection of the SARS-CoV-2 virus. Addition of graphene as a 2D material enhances the sensitivity for detecting biomolecules. Graphene serves as a bio recognizing material, facilitating the binding of ample biomolecules on the sensing surface. Through optimization, we achieve a maximum sensitivity of 399.80°/RIU, coupled with remarkable detection accuracy and figure of merit. Hence, the proposed biosensor holds promise for biosensing applications, offering higher sensitivity and utilizing advanced fabrication techniques. [ABSTRACT FROM AUTHOR]

We present a study on the superconducting properties of 500 nm thick NbTiN films grown by reactive co-sputtering on silicon substrates at room temperature. The samples exhibit a chemical composition with Nb (50 at.%) and Ti (50 at.%), revealing a polycrystalline structure characterized by columnar growth and an average lateral grain size of approximately 40 nm. The superconducting critical temperature (Tc) was measured at 13.8 K, and the upper critical field extrapolated to zero temperature reached 22 T, resulting in a coherence length (ξ) of 3.8 nm. The penetration depth (λ) was determined through local magnetic force microscopy measurements conducted at temperatures of 4.25 and 6 K. The obtained values were 400 (15) nm at 4.25 K and 430 (15) nm at 6 K. Extrapolating these measurements to zero temperature, we obtained an estimated value of 380 nm. A comparison was made with samples that underwent thermal annealing at 700 °C, resulting in a reduction of disorder at the nanoscale and an increase in Tc to 14.2 K. Despite this enhancement, the coherence length ξ (0) remained at approximately 3.8 nm, with no appreciable changes in the λ values. Our findings contribute to understanding fundamental superconducting parameters in nitride thin films, with potential applications ranging from resonant accelerator cavities to Josephson junctions and radiation detectors. [ABSTRACT FROM AUTHOR]

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This study introduces a novel phosphate-based packer fluid, designed for use in high-temperature and high-pressure oil and gas wells. The research aims to evaluate the performance of this innovative fluid in comparison with traditional acetate and formate-based fluids. The study highlights the enhanced performance metrics of the phosphate-based fluid, which include a higher density of 114 pcf, moderated pH levels from 13.5 to 10, and a significantly reduced corrosion rate to below 4 mpy, achieved through the addition of diammonium phosphate and potassium vanadate. Moreover, the research presents two machine learning models (an artificial neural network (ANN) and genetic programming (GP)) developed to predict the penetration depth of the phosphate-based fluid. Both models demonstrate high accuracy, with R-square values of 0.9468 and 0.9140, respectively, with the ANN model exhibiting slightly superior performance. The findings of the study indicate that the phosphate-based fluid, free of solubilizers and enhanced with innovative corrosion inhibitors, provides optimal thermal stability, minimal formation damage, and shallow penetration depth, thus representing a significant advancement in well completion technologies. The fluid's distinctive properties and the predictive models' high accuracy highlight its suitability for challenging environments, marking a notable progression in well completion technologies. [ABSTRACT FROM AUTHOR]

Laser welding of thick plates is extremely sensitive to the gap between joints. With the same laser welding parameters, slight adjustment of the gap can lead to different weld morphologies. An appropriate joint gap is conducive to increasing the penetration depth and reducing defects. To investigate the influence of the gap between butt joints on the penetration depth during single-pass laser welding of 20 mm thick EH40 steel, five groups of experiments were conducted with a laser power of 15 kW and a welding speed of 10mm/s, and gap sizes ranging from 0 to 0 .4mm. A finite element model of the temperature field was established for the experimental samples. Using the concept of equivalent substitution, the heat transfer process was used to replace the downward flow of the molten pool along the gap, and the equivalent thermal conductivity was derived to predict the penetration depth under different gap sizes. The results showed that within the gap range of 0–0.3 mm, the penetration depth increased and spatter decreased as the gap increased. When the gap exceeded 0.2 mm, weld depression began to appear. The maximum penetration depth of 19.33 mm was achieved when the gap was 0 .3mm. When the gap reached 0.4 mm, unacceptable severe collapse occurred in the weld. Additionally, the accuracy of the temperature field simulation results was verified by the experimental results.

Abstract Stimulation techniques to enhance fluid pathways are an important tool to make geothermal projects economically feasible. So far, hydraulic stimulation is used almost exclusively for reservoir-wide improvement of the permeability, but induced seismicity poses a challenge. Chemical stimulation on the other hand has been limited to the close vicinity of the borehole and has barely been considered for the creation of enhanced geothermal reservoirs. However, retardation mechanisms reducing the chemical reaction rate can be used to increase the radius of the chemical stimulation thus enabling a reservoir-wide enhancement of fluid pathways. In this work, we review the technologies of retardation mechanisms for chemical stimulation in geothermal systems and identify five groups of retardation techniques: (i) causing impaired mobility of the acid, e.g., by gelling agents; (ii) causing an impaired dissociation, e.g., by the in-situ generation of the reactive compounds; (iii) blocking the mineral surface area, e.g., by alternating injections of pad fluids and acids; (iv) reducing the reaction rate constant, e.g., by cooling; and (v) changing the chemical equilibrium through chelating agents. We found that most applications are currently based on the use of impaired dissociation, but present research focuses on the development and application of chelating agents. Most of these retardation techniques are adopted from the hydrocarbon industry, but there are several techniques that have not been applied in the geothermal context so far for various reasons. We identify a distinctive lack of in-depth descriptions of the retardation techniques in various studies—mostly to protect intellectual property. However, in the light of public concern regarding fracking techniques and to independently assess potential environmental hazards, scientific examination of proposed techniques is indispensable.