Excessive Penetration Research Articles

Experimental study on the buffering mechanism of EPS bead-sand cushions under single and multiple impacts

As a main functional component of rock sheds in rockfall protection projects, traditional sand cushions have shortcomings such as heavy weight and weak buffering capacity. EPS bead-sand cushion can effectively solve these problems, but its buffering mechanism has not been fully revealed. In this study, a series of impact tests were carried out to investigate the performance of EPS bead-sand cushions with different EPS bead contents, and the evolutions of rockfall impact force, penetration depth, earth pressure, and slab vibration under single impact and multiple impacts were comparatively analyzed. The results show that with the addition of EPS beads, the maximum impact force, the peak earth pressure, and the vibration acceleration are significantly reduced. However, the cushion with high EPS bead content is at risk of being penetrated under high energy or multiple impacts, leading to excessive concentration of impact stresses. Furthermore, the EPS beads can alleviate the hardening of the sand cushion under impact through their deformation coordination, but excessive penetration should be prevented in the design of EPS bead-sand cushions. On this basis, combined with traditional sand cushion design theory, an estimation method for the maximum impact force applicable to EPS bead-sand cushion was proposed. The research results can provide a reference for the design and optimization of cushions in actual projects.

Controlled Growth of ZIF-8 Membranes on GO-Coated α-Alumina Supports via ZnO Atomic Layer Deposition for Improved Gas Separation.

This study presents a novel approach for fabricating ZIF-8 membranes supported on α-alumina hollow fibers through the introduction of a graphene oxide (GO) gutter layer and the application of zinc oxide (ZnO) Atomic Layer Deposition (ALD). The method successfully addressed key challenges, including excessive precursor penetration and membrane thickness. The introduction of the GO layer and subsequent ZnO ALD treatment significantly reduced membrane thickness to approximately 300 nm and eliminated delamination issues between the GO layer and the alumina support. The optimized membranes demonstrated enhanced propylene permeance, with values approximately three times higher than those of membranes without GO, and achieved higher separation factors, indicating minimal inter-crystalline defects. Notably, the GO layer influenced the microstructure, leading to an increase in permeance with rising temperatures. These findings highlight the potential of this strategy for developing high-performance ZIF-8 membranes for gas separation applications.

"Mitotic" kinesin-5 is a dynamic brake for axonal growth.

During neuronal development, neurons undergo significant microtubule reorganization to shape axons and dendrites, establishing the framework for efficient wiring of the nervous system. Previous studies from our laboratory demonstrated the key role of kinesin-1 in driving microtubule-microtubule sliding, which provides the mechanical forces necessary for early axon outgrowth and regeneration in Drosophila melanogaster. In this study, we reveal the critical role of kinesin-5, a mitotic motor, in modulating the development of postmitotic neurons. Kinesin-5, a conserved homotetrameric motor, typically functions in mitosis by sliding antiparallel microtubules apart in the spindle. Here, we demonstrate that the Drosophila kinesin-5 homolog, Klp61F, is expressed in larval brain neurons, with high levels in ventral nerve cord (VNC) neurons. Knockdown of Klp61F using a pan-neuronal driver leads to severe locomotion defects and complete lethality in adult flies, mainly due to the absence of kinesin-5 in VNC motor neurons during early larval development. Klp61F depletion results in significant axon growth defects, both in cultured and in vivo neurons. By imaging individual microtubules, we observe a significant increase in microtubule motility, and excessive penetration of microtubules into the axon growth cone in Klp61F-depleted neurons. Adult lethality and axon growth defects are fully rescued by a chimeric human-Drosophila kinesin-5 motor, which accumulates at the axon tips, suggesting a conserved role of kinesin-5 in neuronal development. Altogether, our findings show that at the growth cone, kinesin-5 acts as a brake on kinesin-1-driven microtubule sliding, preventing premature microtubule entry into the growth cone. This regulatory role of kinesin-5 is essential for precise axon pathfinding during nervous system development.

Modulating Neuromorphic Behavior of Organic Synaptic Electrolyte-Gated Transistors Through Microstructure Engineering and Potential Applications.

Organic synaptic transistors are a promising technology for advanced electronic devices with simultaneous computing and memory functions and for the application of artificial neural networks. In this study, the neuromorphic electrical characteristics of organic synaptic electrolyte-gated transistors are correlated with the microstructural and interfacial properties of the active layers. This is accomplished by utilizing a semiconducting/insulating polyblend-based pseudobilayer with embedded source and drain electrodes, referred to as PB-ESD architecture. Three variations of poly(3-hexylthiophene) (P3HT)/poly(methyl methacrylate) (PMMA) PB-ESD-based organic synaptic transistors are fabricated, each exhibiting distinct microstructures and electrical characteristics, thus serving excellent samples for exploring the critical factors influencing neuro-electrical properties. Poor microstructures of P3HT within the active layer and a flat active layer/ion-gel interface correspond to typical neuromorphic behaviors such as potentiated excitatory postsynaptic current (EPSC), paired-pulse facilitation (PPF), and short-term potentiation (STP). Conversely, superior microstructures of P3HT and a rough active layer/ion-gel interface correspond to significantly higher channel conductance and enhanced EPSC and PPF characteristics as well as long-term potentiation behavior. Such devices were further applied to the simulation of neural networks, which produced a good recognition accuracy. However, excessive PMMA penetration into the P3HT conducting channel leads to features of a depressed EPSC and paired-pulse depression, which are uncommon in organic synaptic transistors. The inclusion of a second gate electrode enables the as-prepared organic synaptic transistors to function as two-input synaptic logic gates, performing various logical operations and effectively mimicking neural modulation functions. Microstructure and interface engineering is an effective method to modulate the neuromorphic behavior of organic synaptic transistors and advance the development of bionic artificial neural networks.

Surface Modification of Silk Fabric by Polysaccharide Derivatives towards High-Quality Printing Performance Using Bio-Based Gardenia Blue Ink.

Ink-jet-printed silk, a premium textile material, was achieved by utilizing a bio-based gardenia blue dye. However, the sharpness of the printing pattern is difficult to control due to the limited water-retention capacity of silk. To address this issue, three polysaccharide derivatives, namely, sodium alginate (SA), low-viscosity hydroxypropyl methyl cellulose (HPMC-I), and high-viscosity hydroxypropyl methyl cellulose (HPMC-II), were employed as thickeners to modify the silk by the dipping-padding method. Firstly, the preparation of the gardenia blue ink and the rheology assessment of the thickener solution were conducted. Furthermore, the impacts of different thickeners on the micro-morphology, element composition, and hydrophilicity of the silk, along with the wetting behavior of the ink on the silk, were analyzed comparatively in order to identify an appropriate thickener for preserving pattern outlines. Lastly, the color features, color fastness, and wearing characteristics of the printed silk were discussed to evaluate the overall printing quality. Research results showed that the optimized ink formulation, comprising 12% gardenia blue, 21% alcohols, and 5.5% surfactant, met the requirements for ink-jet printing (with a viscosity of 4.48 mPa·s, a surface tension of 34.12 mN/m, and a particle size of 153 nm). The HPMC-II solution exhibited prominent shear-thinning behavior, high elasticity, and thixotropy, facilitating the achievement of an even modification effect. The treatment of the silk with HPMC-II resulted in the most notable decrease in hydrophilicity. This can be attributed to the presence of filled gaps and a dense film on the fibers' surface after the HPMC-II treatment, as observed by scanning electron microscopy. Additionally, X-ray photoelectron spectroscopy analysis confirmed that the HPMC-II treatment introduced the highest content of hydrophobic groups on the fiber surface. The reduced hydrophilicity inhibited the excessive diffusion and penetration of gardenia blue ink, contributing to a distinct printing image and enhanced apparent color depth. Moreover, the printed silk demonstrated qualified color fastness to rubbing and soaping (exceeding grade four), a soft handle feeling, an ignorable strength loss (below 5%), and a favorable air/moisture penetrability. In general, the surface modification with the HPMC-II treatment has been proven as an effective strategy for upgrading the image quality of bio-based dye-printed silk.

Planning renewables in distribution system with electric vehicles to improve hosting capacity and energy losses: Two-stage stochastic optimization framework

Excessive penetration of renewables in distribution system can create several operational issues. One of the technologies that can maximize accommodation of renewables is electric vehicles (EVs). However, along with EVs additional measures are required while maximizing hosting capacity (HC) to avoid negative impact on system and account for uncertain parameters. In this regard, this paper proposes a two-stage stochastic optimization approach for planning of renewables in distribution system integrated with EVs. In the first stage, capacity of renewables is determined while maximizing HC whereas in the second stage operating strategy of EVs, renewables and grid power is evaluated to minimize expected energy losses. The proposed framework includes uncertainties in load demand, renewables and EVs characteristics through stochastic programming approach. The optimization problem is formulated as second order cone programming problem. The proposed model is tested on modified IEEE-33 bus and real-life 108-bus Indian distribution systems with different charging/discharging patterns and penetration rates of EVs. Moreover, an economic based cost analysis to compare planning cost and EV charging cost is also provided. Simulation results reveal that in 33-bus system with 500 EVs, the HC with vehicle-to-grid capability (V2G) is higher as compared to uncoordinated and coordinated charging by 29.86% and 6.36% respectively, while in 108-bus system with 1000 EVs, it is higher by 18.51% and 5.69% respectively. Further, the energy losses with V2G are 27.54% and 1.36% less in 33-bus system and 7.31% and 3.22% less in 108-bus system as compared to uncoordinated and coordinated charging respectively.

Oral Infections in Ancient Human Skulls in 2000 BC/Iron Age, Iran.

Oral infections have been seen in humans since ancient times. Excessive penetration of this infection can cause human death. Most of these infections are gum cysts and abscesses. The cyst creates large hard lumps in the gums, which is causes loose, and protruding teeth and abscesses, causing cavities in the jawbone and teeth. In this article, we have discussed for this infectious disease in 4000 - year - old ancient humans from Qazvin Province, Iran. The bone remains of our research are related to Sagezabad ancient cemetery in Qazvin plain. We tried to use reliable international atlases to get detailed information about ancient oral infections. The bones were extracted from the 2019 excavation of the Ghara Tappe area of Sagezabad for the Iron Age 2nd and 3rd Qazvin plains of Iran. This cemetery belongs to the period of the Medes Kingdom (pre - Achaemenian kingdom) in Iran. We have discussed one of the ancient cemeteries with a large number of ancient populations. In this cemetery, there are signs of war and infectious diseases on the bones, which can be clearly seen. We have specially mentioned the abscess as the cause of oral infection from Sagezabad cemetery. Oral infection existed in Iran since 2000 BC. Of course, this infection was common in ancient times and even Paleolithic period, like Homo Heidelbergensis.

Experimental and numerical investigations on the force characteristics of cutter in different regions of the TBM cutterhead

The cutters on the cutterhead of a tunnel boring machine (TBM) are usually divided into center cutters, face cutters, and gage cutters, and have significantly different force characteristics. In this study, the authors conduct a series of full-scale cutter rotary cutting tests to compare the differences in the cutter force, the morphology of rock ships, and the efficiency of rock breaking. The results indicate that with increasing cutter spacing, the influence exerted by the cutters on one another in terms of their performance at breaking rocks decreases and their normal force gradually increases, while the rolling force of the cutters is less influenced by the spacing between them. The ratio of the normal force to the rolling force of the gage cutter is less than that of the face cutter, indicating a lower efficiency of breaking rock of the gage cutter. The ratio of rock chips with larger size (>50 mm) and smaller size (<10 mm) gradually decreases while that of rock chips with medium size (about 10–50 mm) gradually increases with increasing installation angle, such that the distribution of the particle size becomes more uniform. Excessive or insufficient penetration rate (PR) will increase the proportion of small rock chips, and a moderate PR will produce rock chips with a larger characteristic size and a more uniform size distribution. Then, a three-dimensional rock-breaking model by all cutters of actual TBM cutterhead is established based on the particle flow method. The results of the simulations indicate that the force on the inner ring of the center cutter is greater than that on the outer ring, and an increase in the installation radius weakens the load difference between the two rings. The normal and rolling forces of face cutters gradually increase, while their side force first increases and then decreases. The side force of the gage cutter significantly increases with the installation angle.

Prediction of the penetration depth of particle-loaded inks in binder jetting

Prediction of the penetration depth of particle-loaded inks in binder jetting

A new strategy for the preparation of wood-epoxy resin composites reinforced with controllable osmotic interfaces

As a multifunctional material, wood is widely used in interior decoration and construction engineering. The full-cell process of impregnating monomers into wood pores cavity in situ is one of the most common wood modification methods. However, this approach is time-consuming, material-wasting, and not environmentally friendly. In this study, we proposed a simple strategy to directly convert wood into high-performance composites by controlling wood surface penetration through resin pre-curing. A slight amount of resin used was sufficient to penetrate the wood surfaces, and the weight percent gain (WPG) of 11.45 %. High energy efficiency was achieved by simple temperature control (60 °C/120 °C). In addition, this method can rapidly produce wood composites with ultra-low density (0.51 g/cm3) and ultra-high specific bending strength (284 MPa·cm3g−1) in a very short time (4 h and 30 min). The results showed that the problem of excessive resin penetration was effectively solved by the pre-curing process, which enriched the gradient distribution of resin from the surface to the bottom of the wood and significantly improved the material properties. This efficient and environmentally friendly preparation strategy makes natural wood a low-cost, low-density, high-strength engineering material, which broadens the application of wood composites in construction engineering and interior decoration.

Utilisation of electric vehicles and battery energy storage systems for the enhancement of PV hosting capacity in a distribution network

To foster decarbonisation of the transportation sector, there is a growing widespread global adoption of electric vehicles (EVs) as a clean, environmentally friendly alternative to fossil-fuel-dependent internal combustion engine vehicles (ICEV). This has required the electrical power system to distribute power to EV charging stations. In addition, battery energy storage systems (BESSs) have also been deployed to improve network resilience. Both EVs and BESSs on distribution networks (DNs) may be charged using photovoltaic (PV) resources. Subsequently, huge numbers of PV plants have been installed globally over the past decade. With excessive PV penetration into the distribution network (DN), the consequences are risks of operational constraint violations such as over-voltages, feeder line congestion, protection maloperation and high harmonics. This requires limiting the amount of installed PV to alleviate these risks. The maximum amount of PV which can be integrated into the DN without violating these network operational limits is the PV hosting capacity (PVHC). This paper proposes models for quantifying the impacts of EVs and BESSs on the PV hosting capacity of DNs using the stochastic particle swarm and gradient descent algorithm (PSO-GD). The simulation results of case studies have shown that the proposed method is accurate, fast, and efficient.

Numerical simulation analysis of the temperature field in induction heating-assisted flow drilling of the 7075 aluminum alloy

Flow drill riveting (FDR) is a unique method designed for the joining of disparate materials such as aluminum alloys and carbon fiber-reinforced polymers (CFRPs). The success of FDR hinges on the frictional penetration process executed by the blind rivet. When deploying FDR for the joining of high-strength materials, a substantial penetration force often arises, leading to deformations in the workpieces and potentially causing failure in the joining process. To mitigate the excessive penetration force, the use of induction heating to pre-warm the workpiece before the FDR process has been suggested. This led to the development of the induction heating-assisted flow drill riveting (IHFDR) method. In this work, a FEM model was built for the IHFDR penetration process. This model was specifically designed for the AA7075-T6 sheet, utilizing the ABAQUS software. Induction preheating impact on the temperature of the workpiece during the rivet penetration process was scrutinized. The analysis revealed that the workpiece’s peak temperature during the rivet penetration process was elevated due to induction preheating. Furthermore, it was observed that as the preheating elevated the workpiece temperature, the rate of increase for the peak temperature lessened.

An investigation on the laser welding process parameter effects on the failure mode of tailor welded blanks during the formability testing

The ability to produce high-quality weld with the least distortion and heat affected zone width by the Nd:YAG laser welding process has made it one of the best candidates for steel tailor welded blanks (TWBs). The effect of process parameters including laser peak power, pulse duration, welding speed, and thickness ratio on the mechanical properties and failure modes of TWBs were investigated. TWBs was made of St12 carbon steel sheets with different thickness of 0.5 mm, 1 mm, and 1.5 mm. The weld zone hardness profile in all samples followed a similar pattern, in that the maximum hardness was in the weld metal and gradually fell throughout the heat affected zone (HAZ) until it reached the hardness of the base metal at the end of the HAZ and the hardness of weld metal increased as the average joint thickness increased. Based on the distribution of hardness in different regions of the weld zone a simple model was proposed for failure mode. Weld metal failure mode (WFM) happened as a result of weld metal thickness reduction caused by incomplete weld penetration or excessive penetration. The heat input per unit volume of weld in thin sheet (Hin) was defined as a criterion that determines failure mode. Therefore, a qualitative criterion was proposed for the prediction of failure mode. Based on this simple model, there is an appropriate limit for Hin for all thickness ratios at which the failure mode is base metal failure mode (BFM). The WMF happens at values lower and higher than this appropriate value range. The experiments approved that BFM and the highest formability and joint strength were obtained when 11J/mm3<Hin<37J/mm3.

Defects detection of GMAW process based on convolutional neural network algorithm

It is significant to predict welding quality during gas metal arc welding process. The welding defect detection algorithm has been developed based on convolutional neural network (CNN). The sensing system and image processing algorithm for molten pools has been developed. It overcomes the interference caused by the arc light to obtain clear images of the molten pool's boundaries. The molten pools images are used to build up training set and test set for training and testing the CNN model. The model is designed to extract the visual features of molten pool images to predict the penetration state, the welding crater, and slags. Through optimizing the network parameters such as kernel-size, batch-size and learning rate, the prediction accuracy is higher than 95%. Moreover, the model enhances additional focus on the welding crater based on the welder experience. The mechanisms between molten pool characteristics and welding defects were analyzed based on the welder experience and the visual features of the model. It is found that the model judges the occurrence of burn-through with the black hole in the middle zone of the molten pool. When the surface pores are generated, the model exhibits a strong response to circular voids in the semi-solid region at the trailing end of the molten pool. The size and shape of fusion holes exhibit a strong correlation with the molten state. When the shape of the crater does not appear concave, it often signifies excessive penetration. It contributes to enhancing the algorithm's robustness during various welding scenarios.

Designing energy-efficient and visually-thermally comfortable shading systems for office buildings in a cooling-dominant climate

Windows and their control elements, including shading systems, are among the most critical building components affecting both energy consumption and occupant comfort. With the increasing demand for full-glazed facades, designers and researchers are actively devising advanced control strategies to address the challenges posed by excessive sunlight penetration and heat transfer. These strategies aim to harmonize the benefits of natural light with the need for comfortable indoor environments and energy consumption reduction. This study investigates the impact of external shading configurations for an office room in Tehran, categorized as group B in the Köppen climate classification, to reduce total building energy consumption and improve occupant thermal and visual comforts. The shading parameters include shading angle, shading depth, and the number of shading slats. More specifically, this study analyzes and compares two design configurations for the considered office room. The first configuration consists of a single southern window with horizontal shading, whereas the second configuration consists of two windows on the south and west, one being horizontal shading on the southern side and the other being vertical shading on the western side. There are a total of 1330 models investigated from which 20 models are selected as the most suitable solutions. Finally, this paper examines the effect of each design parameter on the overall performance of each configuration in terms of energy efficiency and visual-thermal comfort.

Usefulness of a drill stopper to prevent iatrogenic soft tissue injury in orthopedic surgery

ObjectiveThis study introduces a novel technique utilizing a drill stopper to limit drill penetration depth and to prevent iatrogenic injuries, specifically neurovascular damage, in orthopedic surgeries. Orthopedic surgeries frequently involve the use of drills, which are essential tools for various procedures. However, improper handling of drills can lead to iatrogenic soft tissue injuries, causing severe consequences such as permanent disability or life-threatening complications. To address this issue, we propose the use of a drill stopper as a safeguard to prevent excessive drill penetration and reduce the risk of soft tissue damage during surgery. Materials and MethodsThe study involved 32 orthopedic surgeons, half of whom were experienced and the other half inexperienced. Synthetic femur bone models (Synbone) were used for drilling exercises, employing four configurations: a sharp drill bit without a stopper (SF, Sharp Free), a sharp drill bit with a stopper (SS, Sharp Stopper), a blunt drill bit without a stopper (BF, Blunt Free), and a blunt drill bit with a stopper (BS, Blunt Stopper). Each participant conducted three trials for each configuration, and the penetration depth was measured after each trial. ResultsFor experienced surgeons, the average penetration depths were 3.83 (±1.826)mm for SF, 11.02 (±3.461)mm for BF, 2.88 (±0.334)mm for SS, and 2.75 (±0.601)mm for BS. In contrast, inexperienced surgeons had average depths of 8.52 (±4.608)mm for SF, 18.75 (±4.305)mm for BF, 2.96 (±0.683)mm for SS, and 2.83 (±0.724)mm for BS. ConclusionThe use of a drill stopper was highly effective in controlling drill penetration depth and preventing iatrogenic injuries during orthopedic surgeries. We recommend its incorporation, particularly when using a blunt drill bit or when an inexperienced surgeon operates in an anatomically unfamiliar area. Using the drill stopper, the risk of severe injuries from excessive drill penetration can be minimized, leading to improved patient safety and better surgical outcomes.

Experimental and theoretical study on cooling performance of membrane roof with circulated water film

Membrane roofs are widely used in buildings for excellent daylight and visual effects. Nevertheless, excessive solar penetration results in an overheated indoor thermal environment. The experimental and theoretical study on the cooling performance of circulated water film technology on membrane roofs was conducted. The scale experiment results indicated that with circulated water film the membrane surface temperatures decreased rapidly to a level slightly above the water temperature, where the polyvinylidene fluoride (PVDF) and ethylene tetrafluoroethylene (ETFE) membranes were 0.4 and 2.4 °C higher than water temperature. While the indoor air temperature gradually decreased in instances where PVDF roofs were utilized, the application of ETFE roofs did not yield a significant decrease in temperature. Subsequently, we derived an analytical solution for the dynamic two-dimensional heat and mass transfer process of the water film flowing on the membrane with incident solar radiation, which was validated by experiment. The analysis of influential factors indicated that the temperature drop increased with absorbed solar radiation and outdoor dry-bulb temperature, and decreased with the ambient wet-bulb temperature. Conversely, the cooling performance exhibited minimal sensitivity to variations in water film thickness. The indoor operative temperature dropped by 0.5–0.8 °C in the membrane roofed atrium with water film. The water film effectively cools the indoor thermal environment with membrane roofs.

Evaluation and Application of SMRT Model for L-Band Brightness Temperature Simulation in Arctic Sea Ice

Using L-band microwave radiative transfer theory to retrieve ice and snow parameters is one of the focuses of Arctic research. At present, due to limitations of frequency and substrates, few operational microwave radiative transfer models can be used to simulate L-band brightness temperature (TB) in Arctic sea ice. The snow microwave radiative transfer (SMRT) model, developed with the support of the European Space Agency in 2018, has been used to simulate high-frequency TB in polar regions and has obtained good results, but no studies have shown whether it can be used appropriately in the L-band. Therefore, in this study, we systematically evaluate the ability of the SMRT model to simulate L-band TB in the Arctic sea ice and snow environment, and we show that the results are significantly optimized by improving the simulation method. In this paper, we first consider the thermal insulation effect of snow by adding the thermodynamic equation, then use a reasonable salinity profile formula for multi-layer model simulation to solve the problem of excessive L-band penetration in the SMRT single-layer model, and finally add ice lead correction to resolve the large influence it has on the results. The improved SMRT model is evaluated using Operation IceBridge (OIB) data from 2012 to 2015 and compared with the snow-corrected classical L-band radiative transfer model for Arctic sea ice proposed in 2010 (KA2010). The results show that the SMRT model has better simulation results, and the correlation coefficient (R) between SMRT-simulated TB and Soil Moisture and Ocean Salinity (SMOS) satellite TB is 0.65, and the RMSE is 3.11 K. Finally, the SMRT model with the improved simulation method is applied to the whole Arctic from November 2014 to April 2015, and the simulated R is 0.63, and the RMSE is 5.22 K. The results show that the SMRT multi-layer model is feasible for simulating L-band TB in the Arctic sea ice and snow environment, which provides a basis for the retrieval of Arctic parameters.

Smart Advancements for Targeting Solid Tumors via Protein and Peptide Drug Delivery (PPD).

Proteins and peptides possess considerable potential in treating solid tumors because of their unique properties. At present, there are over 100 peptide-based formulations on the market. Today, peptides and proteins are in more demand due to their selective nature and high target-binding efficiency. Targeting solid tumors with compounds of molecular weight less than 10 kDa are much more desirable because they undergo excessive penetration in view of the fact that they are small sized. The solid tumors have thick tissues and possess excessive interstitial fluid pressure, because of which high molecular compounds cannot enter. The properties of proteins and peptides induce low toxic effects and lessen the major side effects caused by chemical-based drugs. However, their delivery is quite challenging as most proteins and peptides stop functioning therapeutically when following a parenteral route of administration. This paper elaborates on the importance of new age formulations of peptides and proteins followed by their recently documented advancements that increase their stability and delay their metabolism, which helps to target solid tumors.

The GMAW Process Using a Two-Dimensional Arc Deflection with AC Hot Wires

Heat input in gas metal arc welding (GMAW) directly correlates with the applied current. As a result, welding irregularities, such as incomplete fusion and excessive penetration, increase and mechanical properties decrease. One way for adjusting heat input is to use hot wire technology. In this article, a two-dimensional arc deflection in GMAW was presented by simultaneous application of two alternating current (AC) hot wires. It is shown how the positioning of the hot wires and the signal characteristics of the current intensity influenced the deflection pattern and weld quality. It was found that the magnetic fields of the two hot wires overlapped due to the narrow opening between. Therefore, an increased one-dimensional deflection resulted. To obtain a two-dimensional deflection, it was necessary to shield the magnetic fields from each other by means of a ferritic material. By pulsing or phase shifting the current signals, individual deflection patterns were possible. The effect of arc deflection was visualized with highspeed recordings and metallographic investigations. Different deflection patterns were generated to adjust heat input and counteract weld irregularities. The use of hot wire technology allowed an increase in deposition rate by simultaneous improvement of weld quality.