Calculation Of Penetration Depth Research Articles

Analytical model of penetration depth and energy dissipation considering impact position

In the research of projectile penetration into reinforced concrete, the discreteness of penetration depth widely exists in the experiments and empirical formulas, and different impact positions are one of the main reasons for this discreteness. However, the existing theoretical models considering impact position require self-programming methods to solve, and analytical solutions for penetration depth have not been provided. Moreover, existing penetration depth formulas have not dealt with the influence of impact position on penetration depth. To incorporate the influence of the impact position in the penetration depth formulas, this study has investigated different impact positions of the projectile penetration. Herein, the Young formula is used as an example, the projectile penetration process is regarded as a uniformly variable motion based on the constant resistance assumption, two methods are used to obtain the penetration constant resistance, and the energy dissipation of the steel bar at three typical impact positions is theoretically modeled. Finally, analytical solutions for the penetration depth at the three positions are proposed and the mechanism of differences at the three typical impact positions is revealed. In addition, finite element models are established for the three impact positions based on published penetration tests. The penetration depth and steel bar energy consumption of the three impact positions are compared and analyzed, and the analytical model is verified. The results suggest that different impact positions can cause different energy consumption of the steel bar, ultimately leading to varying penetration depth. This analytical model, which fully considers the impact positions of the projectile and the arrangement of the steel bars, can be generalized to any penetration resistance theoretical model or penetration depth calculation formula. It can play an important role in further improving and developing the penetration depth calculation formula, and guiding the design of reinforced concrete protection engineering.

Adhesion Characterization and Enhancement between Polyimide-Silica Composite and Nodulated Copper for Applications in Next-Generation Microelectronics.

As the need for high-speed electronics continues to rise rapidly, printed wiring board (PWB) requirements become ever-more demanding. A typical PWB is fabricated by bonding dielectric films such as polyimide to electrically conductive copper foil such as rolled annealed (RA) copper and is expected to become thinner, flexible, durable, and compatible with high-frequency 5G performance. Polyimide films inherently feature a higher coefficient of thermal expansion (CTE) than copper foils; this mismatch causes residual thermal stresses. To attenuate the mismatch, silica nanoparticles may be used to reduce the CTE of PI. A nodulated copper surface can be used to enhance the Cu/PI adhesion by additional bonding mechanisms that could include a type of mechanical bonding, which is a focus of this study. In this investigation, a 90° peel test was used to measure the peel strength in copper/polyimide/copper laminates containing nodulated copper and polyimide reinforced with 0, 20, and 40 wt % silica nanoparticles. The influence of silica nanoparticles on the peel strength was quantitatively evaluated. Laminates incorporating polyimide films lacking silica nanoparticles had a ∼3.75× higher peel strength compared with laminates reinforced with 40% silica. Their failure surfaces were analyzed by using scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy to identify the mode of failure and to understand bonding mechanisms. The key bonding mechanism, mechanical interlocking, was achieved when the polyimide surrounded or engulfed the copper nodules when the laminate was created. Post-testing failure surface analysis revealed the presence of copper on the polyimide side and polyimide on the copper side, indicating mixed mode failure. An analytical model was developed to determine the impact of applied pressure, temperature, and time on the polyimide penetration and mechanical interlocking around the copper nodules. The model was validated by measuring the peel strength on another set of specimens fabricated using increased temperature and pressure that showed a 3× increase in peel strength compared to lower temperature/pressure processing conditions. This enhanced adhesion resulted from the lower polymer material viscosity at higher temperatures, which fosters deeper and more complete penetration around the copper nodules during processing at higher pressures for longer durations. The methodology of combining peel testing, viscosity and CTE measurement, SEM/EDX, surface chemical analysis, and penetration depth calculation developed herein enables the calculation of the desired processing parameters to enhance functionality and improve adhesion.

Calculation of penetration depth of a support retaining system anchored on the top, for underground network and buried energy pipelines

AbstractThe object of the present paper is to determine the minimum support requirements provided for the safe execution of trench excavation works for underground network receptacles. This term is used to define the open excavations, which are carried out for underground networks to be installed or constructed, and which are classified in terms of place of execution and soil categories. This paper focuses on the study of the free earth support method in excavations carried out in earthy soils and in places where the passage of the pipeline requires deep excavations of vertical front. In these cases, for reasons of safety of both the personnel and the equipment, it is necessary to support the vertical excavation fronts, even when the analyses indicate their stability. In this context, and to avoid the consequences, before the start of the excavation and at its limit, the formation of vertical support structures is required, which are commonly known as "retaining bulkheads". The basic criteria for selecting the type of the support system are soil characteristics, local conditions (surface load, groundwater table) and finally, the lifetime of the trench. Based on the above, the objective of the study is to investigate the temporary support of vertical fronts of depth trenches about 10 m, the excavation of which is carried out on earthy soil. The study is based on the implementation of the limit equilibrium method, which is applied according to the provisions—guidelines set out in Eurocode 7 (EN 1997). The study investigates the distribution of earth pressures in an anchored retaining structure of a deep excavation by extracting the main design parameters of similar systems. The goal of this work is to select the type of the support system depending on the soil properties (c, γ, φ and Ε) and local conditions, as a prerequisite for safe and rational design, while in the end of the project useful conclusions are drawn.

Calculation of penetration depth under various numerical models for the reflection-type two-coil mutual inductance technique

The two-coil mutual inductance (TCMI) technique is a useful experimental method to derive the magnetic penetration depth λ in a superconducting film after proper numerical calculations, in which various film geometries including infinite, circular and quadrangle films have been utilized. Based on previously reported reflection-type TCMI experimental data taken from NbN and K-adsorbed FeSe thin films, we investigate the validity of various numerical models with different geometries by comparing their calculation results. The calculated values of λ for various film geometries become identical only when the film size is at least three times larger than the coil size. For a rectangular film with a width comparable to the coil size, the numerical models of circular and square film geometries with proper sizes can also be adopted to obtain a similar λ value as that calculated with a rectangular film geometry. Although the true value of λ can be approximately achieved only after a complicated calibration, its calculated temperature dependence is insensitive to the choice of numerical models. With these results, a proper film geometry for the numerical calculation of λ may be selected to effectively improve the calculation efficiency.

Engineering Approximate Analysis Method of Rod Projectile Penetrating Concrete Target

The penetration process of rod projectile into concrete target is very complex, and the theoretical analysis is very difficult. In this paper, by using the engineering approximation method, through some reasonable simplification of the rod projectile penetration model, the analytical formulas of the penetration resistance, penetration depth and other important physical quantities are established. Through the calculation of penetration depth, when the sliding friction coefficient is 0.1, the results are in good agreement with the experimental results. The results show that the higher the projectile density and the sharper the shape of the warhead, the stronger the penetration ability.

Calculation of Penetration Depth of a Support Retaining System Anchored on the Top, for Underground Network and Buried Energy Pipelines

Calculation of Penetration Depth of a Support Retaining System Anchored on the Top, for Underground Network and Buried Energy Pipelines

Theoretical background of light-emitting diode total internal reflection fluorescence microscopy and photobleaching lifetime analysis of membrane-associated proteins-Part II.

The selective microscopic imaging of the plasma membrane and adjacent structures by total internal reflection fluorescence (TIRF) microscopy is a versatile and frequently used technique in cell biology. A reduction of imaging artifacts in objective-type TIRF microscopy can be achieved by circular or multi-spot laser illumination or by using noncoherent light sources that are projected into the back focal plane as a light annulus. Light-emitting diode (LED)-based TIRF excitation is a recent advancement of the latter strategy. While some basic principles of LED-TIRF remain the same as in laser-based methods, the calculation of penetration depth, the flatness of illumination and the amount of available illumination power differ. This study provides the theoretical framework for the construction and adjustment of LED-TIRF. Using state-of-the art high power LED emitters, LED-TIRF achieves excitation efficiencies that are comparable to laser-based systems and homogenously illuminate the entire field of view, thus, allowing variation of the penetration depth or quantitative photobleaching-assisted imaging protocols. Using autofluorescent transmembrane, soluble and membrane-attached fusion proteins, we provide examples for a photobleaching-based assessment of the exchange kinetics of proteins within living human endothelial cells.

Orders of magnitude reduction in the thermal conductivity of polycrystalline diamond through carbon, nitrogen, and oxygen ion implantation

Despite the exceptional thermal and mechanical functionalities of diamond, its superlative properties are highly subject to the presence of point defects, dislocations, and interfaces. In this study, polycrystalline diamond is ion implanted with C3+, N3+, and O3+ ions at an energy of 16.5 MeV, producing an amorphous layer at the projected range and a damaged crystalline region between the surface and amorphous layer. Using time-domain thermoreflectance in combination with thermal penetration depth calculations based upon the multilayer heat diffusion equation, it is determined that reductions in the thermal conductivity can span nearly two orders of magnitude while still maintaining a polycrystalline structure within the regions thermally probed. Dynamical diffraction simulations of high-resolution x-ray diffraction measurements demonstrate the formation of a strained layer localized at the end of range, with much lower levels of strain near the surface. Furthermore, within the polycrystalline region above the amorphous layer, the average number of displacements-per-atom from the ion irradiation is found to be <1%, with mass impurity concentrations much less than 1%. These low defect concentrations within the thermally probed region demonstrate the remarkably large impact that dilute levels of defects from the ion implantation can have on the thermal conductivity of diamond.

DETERMINATION OF THE BALLISTIC CHARACTERISTICS AND THE DAMAGING PROPERTIES OF SELF-MADE LOADING CARTRIDGES OF 7.62*39 CALIBER

In practice of forensic medicine and forensic ballistics there are quite often the cases of different types ofgunshot wounds infliction by atypical damaging elements which were used in illegal independent loading of cartridges to the rifle weapon. The purpose of the researches being performed - studying on a concrete example from criminalistics practice of damaging properties of 7.62 mm rifle bullets of type FMJBT (Full Metal Jacketed Boat Tail) which were used for loading by self-made way cartridges of 7.62 * 39 caliber. Originally, during natural tests in the conditions of a ballistic track the ballistic characteristics of the shot bullets and the value of their ballistic coefficient were established. At the following stage of researches the losses of kinetic energy of rifle bullets on punching blocks of ballistic plasticine with the thickness of 100-140 mm were determined. As a result of tests the character of formation of the damage channel in the thickness of biological tissues simulator is established at the stable and unstable movement of the bullets in the visco elastic medium. Besides, during the researches the values of the parameters necessary for calculations ofpenetration depth of the bullets into a fabric of biological object depending on their speed at the moment of hit in the target, were determined. In particular it was established that at unstable movement of an investigated bullet in thickness of the simulator the value of boundary speed amounts 138.1 m/s, and the value of the medium drag factor - 1.782. Using estimated values offlight speed of the bullets in the trajectory the values of depth wound channels in biological tissues were calculated and the conclusion was drawn on the guaranteed causing of penetrating wounds in all established distances of shooting. Thus, use of the methodfor estimation of damaging properties of investigated bullets, the criterion of which is the length of the wound channel and its boundary value was obviously demonstrated.

Collision detection between point clouds using an efficient k-d tree implementation

Context: An important task in civil engineering is the detection of collisions of a 3D model with an environment representation. Existing methods using the structure gauge provide an insufficient measure because the model either rotates or because the trajectory makes tight turns through narrow passages. This is the case in either automotive assembly lines or in narrow train tunnels.Objective: Given two point clouds, one of the environment and one of a model and a trajectory with six degrees of freedom along which the model moves through the environment, find all colliding points of the environment with the model within a certain clearance radius.Method: This paper presents two collision detection (CD) methods called kd-CD and kd-CD-simple and two penetration depth (PD) calculation methods called kd-PD and kd-PD-fast. All four methods are based on searches in a k-d tree representation of the environment. The creation of the k-d tree, its search methods and other features will be explained in the scope of their use to detect collisions and calculate depths of penetration.Results: The algorithms are benchmarked by moving the point cloud of a train wagon with 2.5 million points along the point cloud of a 1144m long train track through a narrow tunnel with overall 18.92 million points. Points where the wagon collides with the tunnel wall are visually highlighted with their penetration depth. With a safety margin of 5cm kd-PD-simple finds all colliding points on its trajectory which is sampled into 19,392 positions in 77s on a standard desktop machine of 1.6GHz.Conclusion: The presented methods for collision detection and penetration depth calculation are shown to solve problems for which the structure gauge is an insufficient measure. The underlying k-d tree is shown to be an effective data structure for the required look-up operations.

Theoretical Research Progress in High-Velocity/Hypervelocity Impact on Semi-Infinite Targets

With the hypervelocity kinetic weapon and hypersonic cruise missiles research projects being carried out, the damage mechanism for high-velocity/hypervelocity projectile impact on semi-infinite targets has become the research keystone in impact dynamics. Theoretical research progress in high-velocity/hypervelocity impact on semi-infinite targets was reviewed in this paper. The evaluation methods for critical velocity of high-velocity and hypervelocity impact were summarized. The crater shape, crater scaling laws and empirical formulae, and simplified analysis models of crater parameters for spherical projectiles impact on semi-infinite targets were reviewed, so were the long rod penetration state differentiation, penetration depth calculation models for the semifluid, and deformed long rod projectiles. Finally, some research proposals were given for further study.

A model of depth calculation for projectile penetration into dry sand and comparison with experiments

Dry sand can be viewed as a binary material composed of sand grains and pores. The dry sand's high compressibility needs to be considered in projectile penetration depth calculation. Current models for the sand's resistance to projectiles involve experimental data fitting and are valid in only a small range of circumstances. In this paper, the P-alpha equation of state and the Mohr-Coulomb Tresca-limit yield criterion are employed to describe the constitutive relations of the sand. A spherical cavity-expansion model including the compressibility of sand is established. Then a new sand penetration depth calculation method is obtained. Our results are compared with those from other models and experiments. It is found that the spherical cavity-expansion model based on the P-alpha equation of state can describe the dynamic response of sand well and is suitable for calculating the depth of penetration into sand by rigid projectiles with specific nose configurations.

Adsorbate–Metal Bond Effect on Empirical Determination of Surface Plasmon Penetration Depth

The penetration depth of surface plasmons is commonly determined empirically from the observed response for adsorbate loading on gold surface plasmon resonance (SPR) substrates. However, changes in the SPR spectrum may originate from both changes in the effective refractive index near the metal surface and changes in the metal permittivity following covalent binding of the adsorbate layer. Herein, the significance of incorporating an additional adsorbate-metal bonding effect in the calculation is demonstrated in theory and in practice. The bonding effect is determined from the nonzero intercept of a SPR shift versus adsorbate thickness calibration and incorporated into the calculation of penetration depth at various excitation wavelengths. Determinations of plasmon penetration depth with and without the bonding response for alkanethiolate-gold are compared and are shown to be significantly different for a thiol monolayer adsorbate system. Additionally, plasmon penetration depth evaluated with bonding effect compensation shows greater consistency over different adsorbate thicknesses and better agreement with theory derived from Maxwell's equation, particularly for adsorbate thicknesses that are much smaller (<5%) than the plasmon penetration depth. The method is also extended to a more practically applicable polyelectrolyte multilayer adsorbate system.

Measurement and modeling of the low-temperature penetration-depth anomaly in high-quality MgB2 thin films

Based on our measurements of intermodulation distortion in MgB2, we have previously proposed that the π energy-gap in MgB2 entails six nodal lines [Y.D. Agassi, D.E. Oates, and B.H. Moeckly, Phys. Rev. B 80 (2009) 174522]. Here we report high-precision measurements in MgB2 stripline resonators that show an increase of the penetration depth as the temperature is decreased below 5K. This increase is consistent with the ℓ=6 symmetry of the π energy gap that we have proposed. We interpret the increase as a manifestation of Andreev surface-attached states that are associated with the nodal lines of the π energy gap. Penetration-depth calculations are in good agreement with our data. To reconcile the present interpretation with existing literature, we review other penetration-depth data, magnetic-impurity and tunneling experiments, and data on the paramagnetic Meissner effect. We conclude that these data do not rule out the interpretation of our experimental data based on a nodal π energy gap.

Spherical geometric model for absorption electrons/positrons phenomenon: Application to the mean penetration depth calculation

I present a spherical geometric model for the slowing down and transport of electrons and positrons in solids. This latter is mainly based on the Continuous Slowing Down Approximation (CSDA) scheme. In advantage, I have developed an analytical expression of the mean penetration depth at normal and oblique incidence by combination between my model and the Vicanek and Urbassek theory. For this, I have used the Relativistic Partial Wave Expansion Method (RPWEM) and the optical dielectric model to calculate the elastic cross-sections and the ranges respectively. Good agreement was found with the experimental and theoretical data.

Cellular Imaging Using Total Internal Reflection Fluorescence Microscopy: Theory and Instrumentation

Live cell fluorescent microscopy is important in elucidating dynamic cellular processes such as cell signaling, membrane trafficking, and cytoskeleton remodeling. Often, transient intermediate states are revealed only when imaged and quantitated at the single-molecule, vesicle, or organelle level. Such insight depends on the spatiotemporal resolution and sensitivity of a given microscopy method. Confocal microscopes optically section the cell and improve image contrast and axial resolution (>600 nm) compared with conventional epifluorescence microscopes. Another approach, which can selectively excite fluorophores in an even thinner optical plane (<100 nm) is total internal reflection fluorescence microscopy (TIRFM). The key principle of TIRFM is that a thin, exponentially decaying, evanescent field of excitation can be generated at the interface of two mediums of different refractive index (RI) (e.g., the glass coverslip and the biological specimen); as such, TIRFM is ill-suited to deep imaging of cells or tissue. However, for processes near the lower cell cortex, the sensitivity of TIRFM is exquisite. The recent availability of a very high numerical-aperture (NA) objective lens (>1.45) and turnkey TIRFM systems by all the major microscopy manufacturers has made TIRFM increasingly accessible and attractive to biologists, especially when performed in a quantitative manner and complemented with orthogonal genetic and molecular manipulations. This article discusses the optical principles of TIRFM (including a sample calculation of penetration depth), the components of a TIRFM setup, and the use of TIRFM in combination with other imaging modalities.

Establishment of Ink Penetration Model and the Calculation of Penetration Depth inside Paper

To study deeply ink penetration condition inside the paper, an ink penetration model on the basis of Kubelka-Munk theory is built up in the paper, and infer out the formula of ink penetration depth, consisting of paper thickness and various brightness. And then the test value and calculation value of ink penetration depth are compared. The study results show that the two values are almost the same, so the state of ink penetration depth can be effectively estimated just by paper brightness.

An approach to measure trace elements in particles collected on fiber filters using EDXRF

A method developed for analyzes of large number of aerosol samples using Energy Dispersive X-Ray Fluorescence (EDXRF) and its performance were discussed in this manuscript. Atmospheric aerosol samples evaluated in this study were collected on cellulose fiber (Whatman-41) filters, employing a Hi-Vol sampler, at a monitoring station located on the Mediterranean coast of Turkey, between 1993 and 2001. Approximately 1700 samples were collected in this period. Six-hundred of these samples were analyzed by instrumental neutron activation (INAA), and the rest were archived. EDXRF was selected as an analytical technique to analyze 1700 aerosol samples because of its speed and non-destructive nature. However, analysis of aerosol samples collected on fiber filters with a surface technique such as EDXRF was a challenge. Penetration depth calculation performed in this study revealed that EDXRF can obtain information from top 150 μm of our fiber filter material. Calibration of the instrument with currently available thin film standards caused unsatisfactory results since the actual penetration depth of particles into fiber filters were much deeper than 150 μm. A method was developed in this manuscript to analyze fiber filter samples quickly with XRF. Two hundred samples that were analyzed by INAA were divided into two equal batches. One of these batches was used to calibrate the XRF and the second batch was used for verification. The results showed that developed method can be reliably used for routine analysis of fiber samples loaded with ambient aerosol.

Calculation of the Penetration Depth of X-rays in Intact Pharmaceutical Film-Coated Tablets by Microdiffractometory

(i) Develop a method to calculate the penetration depth of X-rays in intact film-coated tablets, and validate it using model bilayer tablets. (ii) Characterize the physical form of drug in intact pharmaceutical film-coated tablets by XRD. An equation for the calculation of the penetration depth of X-rays, as a function of the incident angle, was derived. Model bilayer tablets were prepared to validate the calculation method. The upper layer of the tablets consisted only of microcrystalline cellulose, while the lower layer was a mixture of cerium oxide (10% w/w), blue dye (5% w/w) and microcrystalline cellulose. The total tablet thickness was 3,500 microm, with the upper layer thickness ranging from 200 to 700 microm. The diffracted intensity of a cerium oxide peak in the lower layer was determined using a microdiffractometer system (CuKalpha radiation) with a two-dimensional area detector. The calculated penetration depth of X-rays was compared with that determined by XRD. After validation of the XRD method, commercial ibuprofen tablets were characterized. The penetration depth calculated by the method developed in this study was, in general, in good agreement with that determined experimentally by XRD. In commercial ibuprofen tablets, the coating material exhibited peaks due to TiO2 (25.4 degrees 2 theta) and Fe2O3 (33.3 degrees). However, these did not interfere with the characteristic peak of ibuprofen (22.2 degrees). We developed a method for calculation of penetration depth of X-rays in film-coated tablets and validated it using the model bilayer tablets. This method enables the characterization of the active pharmaceutical ingredient in different regions (at different depths) of the film-coated tablet. Since the technique is nondestructive, the same tablet can be repeatedly analyzed during stability studies.

Design principles for multichannel fringing electric field sensors

This paper presents general rules and principles for designing multichannel fringing electric field (FEF) sensors. A detailed analysis on how the design parameters, especially sensor geometry, affect the performance of FEF sensors is provided. Tradeoffs among different design objectives are explained, and qualitative design rules for balancing these tradeoffs are presented. The rules are illustrated with the design examples of two concentric FEF sensors. The effects of shielding electrode width and substrate thickness on sensor performance were evaluated through finite element simulations. In addition, the performance of the two sensors was compared based on the numerical calculations of penetration depth and signal strength. The comparison proves that the addition of shielding electrodes can improve the penetration depth of FEF sensors.