High Penetration Depth Research Articles

Neodymium-Sensitized Nanoconstructs for Near-Infrared Enabled Photomedicine.

Neodymium (Nd3+ )-sensitized nanoconstructs have gained increasing attention in recent decades due to their unique properties, especially optical properties. The design of various Nd3+ -sensitized nanosystems is expected to contribute to medical and health applications, due to their advantageous properties such as high penetration depth, excellent photostability, non-photobleaching, low cytotoxicity, etc. However, the low conversion efficiency and potential long-term toxicity of Nd3+ -sensitized nanoconstructs are huge obstacles to their clinical translations. This review article summarizes three energy transfer pathways of all kinds of Nd3+ -sensitized nanoconstructs focusing on the properties of Nd3+ ions and discusses their recent potential applications as near-infrared (NIR) enabled photomedicine. This review article will contribute to the design and fabrication of novel Nd3+ -sensitized nanoconstructs for NIR-enabled photomedicine, aiming for potentially safer and more efficient designs to get closer to clinical usage.

Characterization of the effect of fabric’s tensile behavior and sharp object properties on the resistance against penetration

In this study, the penetration procedure of sharp objects with various geometries in the fabric was considered. To this end, five objects consisted of two single edged knives, a double edged knife and two spikes were employed. Tests were performed on fabrics with different applications such as shirting, worsted, elastic denim, artificial leather and tarpaulin. The fabric’s tensile behavior and the tools geometry were probed. Then, the stab resistances of fabrics against mentioned devices were examined and their penetration force, depth and energy were considered. Outcomes illustrated that tool’s geometry has a determinant influence on the stabbing parameters. Fabrics with lower tensile modulus extend easily; therefore, higher penetration depth was obtained and this fact postponed the penetration phenomenon. In addition, the increase in the fabric’s strength resulted in higher penetration force. A direct relation was achieved between sharp tool’s geometry and fabrics destruction, in a way that damages obtained by knives are straight and slim line with cut yarns and fibers in the cross-section; however, the penetration of spikes makes damage with a circle shape and torn and protruded fibers are observed in the cross-section.

An Nd3+-Sensitized Upconversion Fluorescent Sensor for Epirubicin Detection.

We describe here an Nd3+-sensitized upconversion fluorescent sensor for epirubicin (EPI) detection in aqueous solutions under 808 nm laser excitation. The upconversion fluorescence of nanoparticles is effectively quenched in the presence of EPI via a fluorescence resonance energy transfer mechanism. The dynamic quenching constant was 2.10 × 104 M−1. Normalized fluorescence intensity increased linearly as the EPI concentration was raised from 0.09 μM to 189.66 μM and the fluorometric detection limit was 0.05 μM. The sensing method was simple, fast, and low-cost and was able to be applied to determine the levels of EPI in urine with spike recoveries from 97.5% to 102.6%. Another important feature of the proposed fluorescent sensor is that it holds a promising potential for in vivo imaging and detection due to its distinctive properties such as weak autofluorescence, low heating effect, and high light penetration depth.

Developing radio frequency blanching process of apple slice

Compared with traditional hot water (HW) blanching, radio frequency (RF) has the advantages of faster heating rate and higher penetration depth. The aim of this study was to explore the optimum conditions of RF blanching of apple slice and compare the quality of apple subjected to RF and HW. Results showed that the optimum heating rate and uniformity can be obtained when electrode gap was of 120 mm, sample geometry of 50 × 8 × 50 mm, and not superimposed of apple slices, which were used for further RF blanching. It required 111 s and 270 s to reach the target temperature (85 °C) in RF and HW blanching respectively. After treated by RF and HW for 120 s, the residual enzyme activities of PPO of apples were 0% and 61.42 ± 1.48% (P < 0.05), the hardness were 402.83 ± 11.93 g and 469.39 ± 10.24 g (P < 0.05), the weight loss were 10.23 ± 1.01% and 14.39 ± 2.58% (P > 0.05), respectively. There was no significant difference (P > 0.05) in color change.

Effect of Process Parameters on Depth of Penetration &amp;amp; Surface Roughness in Abrasive Waterjet Cutting of Copper

This study evaluates the effect of process parameters on depth of penetration and surface roughness in abrasive waterjet (AWJ) cutting of copper. Full factorial experiments are carried out on trapezoidal blocks for each of the three abrasive particle sizes used. Experimental parameters - abrasive mass flow rate, water jet pressure and traverse speed are varied at three levels. Main effects and contributions of process parameters to depth of penetration and surface roughness is calculated. From the data, it is observed that, high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in higher depth of penetration and a high abrasive mass flow rate, high water jet pressure and low traverse speed resulted in lesser Ravalue. Using experimental data a statistical model for predicting depth of penetration &amp; surface roughness is developed. Error between experimental and statistical values are compared to validate the statistical model. The maximum DOP of 49.32mm was observed at AMFR=405.4 g/min, P=300 MPa, TS=60 mm/min, MS=60 Mesh and minimum DOP of 4.27mm was observed at AMFR=200 g/min, P=100 MPa, TS=90 mm/min, MS=80 Mesh.

Label-Free Non-linear Multimodal Optical Microscopy—Basics, Development, and Applications

Nonlinear optical (NLO) microscopy has proven to be a powerful tool especially for tissue imaging with sub-cellular resolution, high penetration depth, endogenous contrast specificity, pinhole-less optical sectioning capability. In this review, we discuss label-free nonlinear optical microscopes including the two-photon fluorescence (TPF), fluorescence lifetime imaging microscopy (FLIM), polarization-resolved second harmonic generation (SHG) and coherent anti-Stokes Raman scattering (CARS) techniques with various samples. The nonlinear signals are generated from collagen in tissue (SHG), amylopectin from starch granules (SHG), sarcomere structure of fresh muscle (SHG), elastin in skin (TPF), nicotinamide adenine dinucleotide (NADH) in cells (TPF) and lipid droplets in cells (CARS). Again, the nonlinear signals are very specific to the molecular structure of the sample and its relative orientation to the polarization of the incident light. Thus, polarization-resolved nonlinear optical microscopy provides high image contrast and quantitative estimate of sample orientation. An overview of the advancements on polarization-resolved SHG microscopy including Stokes vector based polarimetry, circular dichroism, and susceptibility are also presented in this review article. The working principles and corresponding implements of above-mentioned microscopy techniques are elucidated. The potential of time-resolved TPF lifetime imaging microscopy (TP-FLIM) is explored by imaging endogenous fluorescence of NAD(P)H, a key coenzyme in cellular metabolic processes. We also discuss single laser source time-resolved multimodal CARS-FLIM microscopy using time-correlated single-photon counting (TCSPC) in combination with continuum generation from photonic crystal fiber (PCF). Using examples, we demonstrate that the multimodal NLO microscopy is a powerful tool to assess the molecular specificity with high resolution.

Two-photon fluorescent Zn2+ probe for ratiometric imaging and biosensing of Zn2+ in living cells and larval zebrafish

As an essential transition-metal ion in organism, zinc ion (Zn2+) plays a significant role in cellular metabolism, apoptosis and neurotransmission. Herein, we reported a new intramolecular charge transfer-based two-photon probe, (E)-1-(6-(4-(2-(2-(2-methoxyethoxy)ethoxy)eth-oxy)-3,5-dimethylstyryl)quinolin-2-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine (TEO-MPVQ), for ratiometric imaging and biosensing of Zn2+ in living cells and larval zebrafish. The maximum two-photon absorption cross-section values (δmax) of the developed probe increased from 115 ± 16 GM to 188 ± 27 GM, after the probe was chelated with Zn2+. The emission spectrum of TEO-MPVQ probe increased and red-shifted about 60 nm, resulting in the ratiometric determination of Zn2+ with high sensitivity and selectivity. The present fluorescent probe also demonstrated good biocompatibility, high spatial resolution and deep penetration depth for Zn2+ detection. Accordingly, TEO-MPVQ was able to track the endogenous Zn2+ release in neurons and also successfully applied for larval zebrafish imaging. By using of this effective probe, it was found that the endogenous Zn2+ was rapidly released from metallothionein under the stimulation of NO in neurons.

Modified friction stir clinching of dissimilar AA2024-T3 to AA7075-T6: Effect of tool rotational speed and penetration depth

There is a need to overcome the formation of stress-raisers such as geometric-differential flow-induced defects in modified friction stir clinched dissimilar aluminum alloys in order to improve joint performance. This paper thus examines the modified friction stir clinching of 2024-T3/7075-T6 aluminum alloys with the motive of inhibiting the flow-induced defect by varying tool rotational speed and penetration depth. The results depict that the combined increase in tool rotational speed and penetration depth cutback the severity of geometric-differential flow-induced defect at the weld nugget center due to better flowability and intermingling of materials. Low level of penetration depth induces the formation of repressed upward material flow and forms undesirable unfilled zone with an n-flow profile within the weld nugget owing to insufficient upward material flow and intermixing. Maximum failure stresses of 288.98 MPa (tensile) and 176.52 MPa (cross-tension) were obtained at 1400 rpm and 0.5 mm. Circumferential and defect-induced failure behaviors are the modes of failure in the joints produced at high and low penetration depth respectively.

Influence of resin infiltrants on mechanical and thermal performance in plaster binder jetting additive manufacturing

Plaster Binder Jetting (BJ) is one of the major Additive Manufacturing (AM) technologies which has been in use since the 1990s. It has many advantages such as the ability to print in full color CMY(K), no support structures, and is relatively faster and less expensive when compared to other AM technologies. Since there is no phase transformation (e.g. powder to molten pool in powder bed fusion, directed energy deposition), BJ does not require support structures and enables higher packing density in the build volume. However, relatively lower mechanical strength when compared to other AM processes has mostly limited it to non-functional applications such as prototyping. This paper investigates novel methods to improve the mechanical and temperature performance of plaster BJ additive manufactured parts via improved infiltration processes and incorporation of infiltrants with higher strength. Potential applications include functional end use products, including tooling, jigs and fixtures for higher temperature applications. Three 2-part epoxy resin systems were evaluated as infiltrants in comparison to epoxy and cyanoacrylate (CA) resins recommended by the original equipment manufacturer (OEM). Multiple impregnation methods including hot and wet vacuum were evaluated on their infiltration effectiveness. The best impregnation method was then used to prepare tensile, flexural and compressive samples for additional evaluation of each resin. Statistical analysis was conducted to analyze and compare the data. Both resins and infiltrated samples were individually evaluated using Differential Scanning Calorimetry (DSC) to determine glass transition temperatures and other thermal events. Infiltrated specimens of the best performing resins were evaluated for Heat Deflection Temperature (HDT) performance utilizing Dynamic Mechanical Analysis (DMA). It was found that infiltration is anisotropic, with the higher penetration depth from the sides (between layers) than top and bottom (across layers). Vacuum impregnation resulted in the highest infiltration depth by fully impregnating the 25 mm cubic samples. The best performing epoxy showed a 10% increase in mechanical strength over the OEM epoxy at 76% reduction in cost. The OEM cyanoacrylate had the lowest mechanical strength across all tests. DSC analysis revealed that the plaster and gypsum base material will start to dehydrate above 100 °C and will ultimately limit the parts’ high temperature capabilities. The OEM epoxy showed the highest HDT.

Estimation of energy absorption buildup factors of some human tissues at energies relevant to brachytherapy and external beam radiotherapy

Purpose: Estimation of energy absorption buildup factors (EABFs) of some human tissues for photon energies commonly used in brachytherapy (BT) and external beam radiotherapy (EBRT).Methods: A five parameter geometric progression (G-P) fitting approximation was used to estimate EABF at different energies and penetration depths (up to 20 mfp). MCNP6.1 was used to obtain EABF for comparison.Results: For radiation sources with lower mean energies (MEs), adipose tissue, which has lowest Zeq, has highest EABF values while bone, which has highest Zeq, has lowest EABF values. EABF reaches to a maximum value (EABFmax∼550) for Ir-192 BT source, which has a mean energy of 0.35 MeV. The radiation sources (MEs from 300 keV to a few MeV) were found to have higher values of EABF. At higher energies, e.g. 5 MeV, the annihilation photons contribute EABF at higher penetration depths, e.g. 20 mfp. In general, both MCNP and GP fitted EABF values along with available experimental data were found to agree well.Conclusions: EABFs of various human tissues have been investigated at radiation source energies relevant to BT and EBRT extensively. The presented data on EABF for the human tissues should be useful for accurate dose estimation at BT and EBRT.

On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations

Internal temperature is an essential parameter for understanding ice sheet dynamics. Glaciological models provide estimations of temperature profiles over Antarctica and few boreholes are also available, but, at present, no measurement exists at the scale of the whole continent. The analysis of passive L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite shows that, thanks to the high penetration depth (i.e. up to 1500 m), it is possible to infer information on in depth glaciological properties of the ice sheet including temperature. In this study, the temperature profile is retrieved from SMOS observations using jointly glaciological and emission models. The developed methodology is valid in the inner part of Antarctica where the ice sheet is almost stable (i.e. its velocity is limited to 10 m yr−1). This analysis points out that in several cases, differences are observed between retrieved temperature profiles and those predicted by glaciological models. In particular, some geophysical parameters, namely the geothermal heat flux and the mean annual accumulation, need to be modified with respect to their prior values in order to simulate SMOS brightness temperatures. Results also clearly show that the reliability of the retrieved profile in depth decreases with increasing ice thickness due to the limited penetration of microwaves in the ice. The obtained results prove the capability of L band (1.4 GHz) passive microwave sensors for investigating the internal temperature of the ice-sheet.

Synchrotron X-Ray Microdiffraction Investigation of Scaling Effects on Reliability for Through-Silicon Vias for 3-D Integration

Synchrotron x-ray microdiffraction has been applied to TSV characterization in various studies for nondestructive inspection with submicron resolution due to its high beam intensity and penetration depth. In this paper, the application of this technique to TSV investigations is examined and the correlation of the plastic deformation to the microstructure and extrusion behavior along with the effect of TSV dimensional scaling is examined. It is shown that the variability of the copper microstructure and resulting TSV behavior requires a larger number of samples in order to report statistically significant observations. The role of the microstructure in creating statistical scatter is demonstrated through microdiffraction measurements of grain orientation correlated with the observed peak widening, which shows that degraded TSV reliability is largely due to the high elastic anisotropy of copper. After taking the statistical variations into account, the scaling effect was clearly observed, with larger plastic deformation in $2~\mu \text{m}$ diameter TSVs than in $5~\mu \text{m}$ diameter TSVs consistent with microstructure variations. This is confirmed by TSV extrusion measurements, which show that the magnitude and statistical spread of the via extrusion for the $2~\mu \text{m}$ diameter TSVs is higher than that of the $5~\mu \text{m}$ diameter TSVs. These results, validated by thermomechanical simulation, demonstrate first that large sample sizes are required in copper TSV investigations due to high variability, which is not improved with scaling.

Inhibitory effect of 980-nm laser on neural activity of the rat's cochlear nucleus.

.Near-infrared radiation (NIR) has been described as one of the highest-resolution tools for neuromodulation. However, the poor tissue penetration depth of NIR has limited its further application on some of the deeper layer neurons in vivo. A 980-nm short-wavelength NIR (SW-NIR) with high penetration depth was employed, and its inhibitory effect on neurons was investigated in vivo. In experiments, SW-NIR was implemented on the rat’s cochlear nucleus (CN), the auditory pathway was activated by pure-tones through the rat’s external auditory canal, and the neural responses were recorded in the inferior colliculus by a multichannel electrode array. Neural firing rate (FR) and the first spike latency (FSL) were analyzed to evaluate the optically induced neural inhibition. Meanwhile, a two-layered finite element, consisting of a fluid layer and a gray matter layer, was established to model the optically induced temperature changes in CN; different stimulation paradigms were used to compare the inhibitory efficiency of SW-NIR. Results showed that SW-NIR could reversibly inhibit acoustically induced CN neural activities: with the increase of laser radiant exposures energy, neural FR decreased significantly and FSL lengthened steadily. Significant inhibition occurred when the optical pulse stimulated prior to the acoustic stimulus. Results indicated that the inhibition relies on the establishment time of the temperature field. Moreover, our preliminary results suggest that short-wavelength infrared could regulate the activities of neurons beyond the neural tissues laser irradiated through neural networks and conduction in vivo. These findings may provide a method for accurate neuromodulation in vivo.

A single fluorescent probe for one- and two-photon imaging hydrogen sulfide and hydrogen polysulfides with different fluorescence signals

Reactive sulfur species (RSS), primarily containing glutathione (GSH), cysteine (Cys), hydrogen sulfide (H2S) and hydrogen polysulfides (H2Sn, n > 1), were crucial endogenous biological signal molecules. Among them, H2S and H2Sn played extremely momentous roles in many physiological and pathological processes. Limited by the vivo environmental diversity and complexity, it was highly desirable to rely on the single fluorescence probe platform to visualize H2Sn and H2S according different fluorescence signals. Herein, we reported a two-photon excited fluorescent probe MC-Sn that had the following merits: (Ⅰ) ratiometric and colorimetric: reducing detection errors and conducting visual analysis; (Ⅱ) two-photon microscope: better performance in vivo and vitro imaging; (Ⅲ) two specific sulfide reaction sites: studying on the mutual transformation of H2Sn and H2S in biological systems. Furthermore, take advantages of low cytotoxicity (cell viability ≥ 85.99%), low limit of detection (21 nM), significant photostability, excellent pH stability, quick response behavior (175 s) and high penetration depth (110 μm), MC-Sn can be employed to visualize endogenous and exogenous H2Sn and H2S in cells, liver tissues and zebrafish.

Assessment of Nonradioactive Multispectral Optoacoustic Tomographic Imaging With Conventional Lymphoscintigraphic Imaging for Sentinel Lymph Node Biopsy in Melanoma

The metastatic status of sentinel lymph nodes (SLNs) is the most relevant prognostic factor in breast cancer, melanoma, and other tumors. The conventional standard to label SLNs is lymphoscintigraphy with technetium Tc 99m. A worldwide shortage and known disadvantages of Tc 99m have intensified efforts to establish alternative, nonradioactive imaging techniques. To assess a new nonradioactive method using multispectral optoacoustic tomographic (MSOT) imaging in comparison with conventional lymphoscintigraphic imaging for SLN biopsy (SLNB) in melanoma. Analysis of a cross-sectional study was conducted at the University Hospital-Essen, Skin Cancer Center, Essen, Germany. Between June 2, 2014, and February 22, 2019, 83 patients underwent SLNB with an additional preoperative indocyanine green (ICG) application. Sentinel lymph node basins were preoperatively identified by MSOT imaging, and ICG-labeled SLNs were intraoperatively detected using a near-infrared camera. The surgeons were blinded to the lymphoscintigraphic imaging results in the beginning of the SLNB. Use of a γ probe was restricted until the SLNB procedure was attempted by the nonradioactive method. Concordance of SLN basins and SLNs identified by MSOT imaging plus near-infrared camera vs lymphoscintigraphic imaging plus single-photon emission computed tomographic or computed tomographic imaging was assessed. Of the 83 patients (mean [SD] age, 54.61 [17.53] years), 47 (56.6%) were men. In 83 surgical procedures, 165 SLNs were excised. The concordance rate of ICG-labeled and Tc 99m-marked detected SLN basins was 94.6% (n = 106 of 112). Intraoperatively, 159 SLNs were detected using a near-infrared camera and 165 were detected by a γ probe, resulting in a concordance rate of 96.4%. Multispectral optoacoustic tomographic imaging visualized SLNs in all anatomic regions with high penetration depth (5 cm). The findings of this study suggest that nonradioactive SLN detection via MSOT imaging allows identification of SLNs at a frequency equivalent to that of the current radiotracer conventional standard. Multispectral optoacoustic tomographic imaging appears to be a viable nonradioactive alternative to detect SLNs in malignant tumors.

Supervised Machine Learning Algorithms Can Predict Penetration Resistance in Mineral-fertilized Soils

ABSTRACTIt is desirable for farmers and agricultural engineers to estimate the changes in soil penetration resistance (SPR) due to the usage of mineral fertilizers. However, reliable instruments for such measurements are not always available. In this study, the effects of conventional N, P, and K-based mineral fertilizers are firstly investigated on SPR. Then, machine learning methods are utilized to predict SPR. The cone index as an indicator of SPR was measured in different soil depths between 0 and 90 cm, different soil moisture contents from 10% to 30%, and different soil organic matter contents from 1% to 8%. Experimental data showed that fertilizing treatments were more effective on the SPR of soil samples (p < .05) in higher penetration depths. Double fertilizing of urea resulted in the highest SPR in the studied range of soil depth. Fertilizing treatments, soil moisture contents, soil organic matter contents, and penetration depths as input features of the samples were then trained to the machine using supervised learning methods and the machine’s performance in prediction of SPR was investigated. Results showed that support vector machine resulted in an acceptable performance, normalized MSE and R2 of which were equal to 0.009 and 0.98, respectively using Gaussian kernel with kernel parameter of 30. Findings of this study reveal that machine learning can reliably predict SPR when instruments such as cone penetrometer are not available.

Application of GPR and seismic methods for noninvasive examination of glacial and postglacial sediments in the Psia Trawka glade: the Tatra Mts., Poland

Presented study gives an insight into general proportions of the actual geomorphology, subglacial morphology and thickness of the drift (quaternary sediments) particularly well-pronounced glacial morphology in the Tatras and, on the other hand, the general scarcity of the data in this field. Objectives of the geophysical survey in this study were imaging of the morphology of bedrock surface under the drift (glacial and postglacial) sediments and determination of thickness of the drift and its composition. Two methods were applied: Ground Penetrating Radar (GPR) and seismic refraction profiling. GPR was used to examine drift sediments due to its high resolution and low depth of penetration. Seismic method with lower resolution but higher penetration depth gave an image of boundary between bedrock and drift. In addition, the results of seismic tomography allowed the velocity field imaging which shows changes inside the postglacial deposits. The results of the two methods used in this research suggest that points of depression exist in the subglacial morphology with a depth of about c.a. 40 below the present-day terrain surface and c.a. 25 m below surrounding subglacial surface. This trough has also been estimated to be about 150 m wide. Its considerable depth and steep slopes show that its origin can be related to erosion of subglacial water during the decay of the last (Würm) glaciation of the Sucha Woda and Panszczyca valleys.

A framework of time integration methods for nonsmooth systems with unilateral constraints

A framework of time integration methods for nonsmooth systems with unilateral constraints is established in this paper, which solves non-impulsive dynamic equations at every step, and deals with impulsive dynamic equations at the end of steps that may involve impacts. The computational procedures of the Generalized-α method and the Bathe method are provided to show this framework, and how to select auxiliary parameters in the procedure is discussed for the benefit of applications. In addition, to avoid high penetration depth and improve the accuracy of detection, an adjustable step size strategy is developed. The provided procedures possess second-order accuracy for smooth motion, and errors caused by the approximate treatment of impacts are controlled by setting an allowable penetration depth. Besides, the observed oscillations of contact forces at contact boundary can be effectively filtered out by the Bathe method. Compared with the classical Moreau-Jean time-stepping scheme, the numerical experiment of the slider-crank mechanism validates that the proposed framework enjoys advantages on accuracy and efficiency.

In Vivo Tracking of Tissue Engineered Constructs.

To date, the fields of biomaterials science and tissue engineering have shown great promise in creating bioartificial tissues and organs for use in a variety of regenerative medicine applications. With the emergence of new technologies such as additive biomanufacturing and 3D bioprinting, increasingly complex tissue constructs are being fabricated to fulfill the desired patient-specific requirements. Fundamental to the further advancement of this field is the design and development of imaging modalities that can enable visualization of the bioengineered constructs following implantation, at adequate spatial and temporal resolution and high penetration depths. These in vivo tracking techniques should introduce minimum toxicity, disruption, and destruction to treated tissues, while generating clinically relevant signal-to-noise ratios. This article reviews the imaging techniques that are currently being adopted in both research and clinical studies to track tissue engineering scaffolds in vivo, with special attention to 3D bioprinted tissue constructs.

Printability of 316 stainless steel

ABSTRACTA printability database can help in the selection of a printing process-alloy combination to reduce, and in some cases avoid, common defects in printed parts. The extensive testing of parts is not a viable option for determining printability because printing processes are inherently slow and expensive. Here we evaluate printability of stainless steel 316 by evaluating its susceptibilities to residual stresses, distortion, composition change and lack of fusion defects for laser (DED-L) and arc (DED-GMA) based directed energy deposition and laser powder bed fusion (PBF-L) processes using well-tested mechanistic models. Among these three processes, DED-GMA makes printed parts of 316 stainless steels most susceptible to residual stresses and distortion. High depth of penetration during DED-GMA makes components least susceptible to lack of fusion defects. Loss of volatile alloying elements from the tiny pools in PBF-L makes deposits the most vulnerable to composition change.