Metal Pellets Research Articles

Enhanced hydrothermal liquefaction of tires using zinc and MoS2

This study introduces a novel approach for tire liquefaction employing zinc and unsupported catalyst MoS2 to mitigate oxygen, nitrogen, and sulfur content, while inhibiting poly-aromatic formation. Autoclave experiments were conducted under subcritical water conditions at 360 and 410 °C. Comprehensive characterization of char and oil was performed, encompassing elemental analysis, functional-group assessment, and composition analysis using gas chromatography-mass spectrometry (GC-MS) and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). During the liquefaction, zinc metal pellets react with water to form ZnO and hydrogen, aiding hydrogenation, and MoS2 preserves its catalytic stability. ZnO shows a catalytic effect on deoxygenation, desulfurization, and denitrification reactions. However, the reaction between ZnO and H2S is not favorable under hydrothermal conditions. Zinc and MoS2 synergistically promote cracking of heavier compounds into lighter ones, particularly evident at higher temperatures, without diminishing the overall oil yield. Incorporating zinc pellets and MoS2 slightly facilitates sulfur and oxygen migration from liquid to solid and gas phases. FT-ICR MS analysis reveals oxygen, sulfur, and nitrogen-containing compounds in heavy fraction of oils. The oxygen-containing compounds, predominantly comprised of stearic acid and its derivatives, are identified. Concurrently, the nitrogen-containing compounds manifest primarily as basic nitrogen compounds. MoS2 possesses the capability of forming more N-containing compounds, leading to the generation of a broader spectrum of N-containing compounds. This work elucidates the synergistic role of zinc-assisted catalysis and MoS2, offering insights into tire liquefaction mechanisms and product composition, vital for sustainable waste management and resource recovery.

A Droplet Generator Using Piezoelectric Ceramics to Impact Metallic Pellets.

Metal micro-droplet ejection technology has attracted attention for its potential applications in the rapid prototyping of micro-metal parts and microelectronic packaging. The current micro-droplet ejection device developed based on this technology faces challenges such as the requirement of a micro-oxygen ejection environment, a complex feeding structure, and high costs. Therefore, a drop-on-demand droplet generator for metallic pellets with impact feed ejection is designed in this paper. This device has a simple and compact structure, does not require a high-cost heat source, and can perform drop-on-demand ejection of metallic pellets in an atmospheric environment. A micro-channel feeding method based on piezoelectric ceramic actuator drives is proposed. A rigid dynamics metallic pellet flight trajectory model is established to analyze the relationships between the driving voltage and the flight trajectory of the pellets. With the help of Fluent to simulate and analyze the melting and ejection processes of the pellets inside the nozzle, the changes in the variable parameters of the flow field in the process of the melting and flight of a single molten drop are studied. The droplet generator produces stable droplets with a 500 µs pulse width and 1100 mm/s initial velocity of the projectile. The simulation results show that a single projectile has to go through three stages including feeding, melting, and ejecting, which take 39.5 ms, 7.85 ms, and 17.65 ms. The total simulation time is 65.0 ms. It is expected that the injection frequency of the metal projectile droplet-generating device will reach 15 Hz.

Effect of experimental parameters on X-ray Micro-CT imaging for Spectral CT applications

Computed tomography (CT) is recognized as a reliable method for structural characterization of different materials. Recently, Spectral CT methods have emerged as a tool to describe the sample composition through assessment of mass density (ρ) and effective atomic number (Zeff) assessment from CT results. These techniques depend on measuring the linear attenuation of a set of standards samples. However, besides ρ and Zeff, these results are influenced by factors such as X-ray energy and may be affected by experimental factors not accounted for in the foundational equation. Thus, in this study, we propose to quantify the effects of two factors: uniaxial compression and image pixel size on measurements of linear attenuation assessed through the registered mean gray value and its standard deviation. Initially, a group of metallic oxides pellets were compressed under different pressures and scanned at various magnification factors. Subsequently, based on factorial design theory, Yates’ method was applied to evaluate the significant effects of the factors. In a second phase, using a group of known samples, a Dual-Energy CT (DECT) measurement of a validation sample was conducted to verify the quantified effects. As expected initially, we observed that uniaxial compression positively influences attenuation, as it directly affects mass density. However, we found that an increase in image pixel size leads to a decrease in registered attenuation as it reduces the relationship between radiation attenuation and detected photons. Indeed, for the leveraged variation, the linear effect of pixel size variation proved to be the most influential on the registered mean gray value. When considering these effects in DECT application, no statistical difference was observed between loose powder and pellet measurements. Furthermore, no trend was observed in the results regarding image pixel size. However, it is possible that more significant changes in these factors may yield different results, and therefore, operators applying Spectral CT methods must ensure that the same experimental conditions are applied to both the standard sample set and the sample under investigation.

The effectiveness of auricular neuromodulation in childhood and adolescent obesity

detrimental to a child's health. This condition predominantly stems from an interplay of genetic, environmental, and lifestyle factors. Key contributors include unhealthy dietary habits, insufficient physical activity, and prolonged engagement in sedentary activities, such as excessive use of mobile phones, computers, and television. Childhood obesity predisposes individuals to a spectrum of health complications, including cardiovascular diseases, type 2 diabetes, and respiratory disorders. Additionally, it is associated with various psychological and social challenges. The rising prevalence of childhood obesity underscores its seriousness as a growing public health concern, with long-term implications for the health and well-being of affected children. Results: The review identified four surveys that met the predefined outcomes. These studies provided substantial evidence supporting the use of auricular neuromodulation in addressing childhood obesity. Each of the four studies was a randomized clinical trial, focusing on children and adolescents who underwent auricular neuromodulation. This procedure involved the use of vaccaria (plant seeds), metal pellets and mustard seeds. The participants in this study were divided into two subgroups. The first group received intervention with the use of vaccaria and the second group was the control group where there was no intervention. This design facilitated the comparison of the given intervention against alternative treatments. The primary outcome measures included anthropometric parameters and assessments of body image, self-esteem, and depressive symptoms. Conclusion: Recent studies have demonstrated that auricular neuromodulation using vaccaria seeds, mustard seeds and metal pellets yields positive results in treating childhood obesity. This conclusion is based on anthropometric outcome measures. These findings suggest that such neuromodulation techniques can be a viable option in the physiotherapeutic treatment of obesity in children and adolescents.

Measurement of liquidus in metal-rich region of lanthanoid-oxygen binary systems and the thermodynamic evaluation

In this study, the solubilities of oxygen in molten La, Gd, Tb, Ho, and Er metals were measured and the oxide phases in equilibrium with each of these lanthanoid metals were identified to systematically determine the liquidus of lanthanoid-oxygen systems in the metal-rich region. The molten lanthanoid metal and lanthanoid oxide pellets were equilibrated at 1573–1873 K and then quenched. The oxygen concentration in the quenched metals was measured using inert gas fusion infrared absorption spectroscopy to determine the oxygen solubilities of molten lanthanoid metals. The crystal structures of the quenched lanthanoid oxide pellets were analyzed using XRD to identify the equilibrium oxide phases, which were identified as the sesquioxides of each lanthanoid element. Furthermore, the Gibbs free energies of the liquid phases of the Ln-O (Ln = La, Pr, Gd, Tb, Dy, Ho, Er) systems were evaluated using the CALPHAD method and thermodynamic software Pandat based on the oxygen solubilities of molten La, Gd, Tb, Ho, and Er metals measured in this study and those of Pr and Dy reported in previous studies.

Development of thermal conductivity model with use of a thermal resistance circuit for metallic UO2 microcell nuclear fuel pellets

A metallic microcell UO2 pellet has a microstructure where a metal wall is connected to overcome the low thermal conductivity of the UO2 fuel pellet. It has been verified that metallic microcell fuel pellets provide an impressive reduction of the fuel centerline temperature through a Halden irradiation test. However, it is difficult to predict the effective thermal conductivity of these pellets and researchers have had to rely on measurement and use of the finite element method. In this study, we designed a unit microcell model using a thermal resistance circuit to calculate the effective thermal conductivity on the basis of the microstructure characteristics by using the aspect ratio and compared the results with those of reported metallic UO2 microcell pellets. In particular, using the thermal conductivity calculated by our model, the fuel centerline temperature of Cr microcell pellets on the 5th day of the Halden irradiation test was predicted within 6% error from the measured value.

Optimization of metal foam pellet shape in packed beds for improved radial heat transfer using particle-resolved computational fluid dynamics

Process intensification in tubular reforming reactors has always been a topic of interest, particularly for improving the radial heat transfer. The innovation of open-cell metallic foam pellets is the latest in this category, as they bear unique transport properties. This work presents the optimization of metal foam pellet shapes for improved radial heat transport, using a virtual design platform based on a modified version of particle-resolved computational fluid dynamics. To optimize the pellet geometry, different configurations such as pellet with inner holes, external grooves, and varied aspect ratios, as well as different foam morphologies (cell size ϕ and porosity ε) are considered, and the influence of each pellet configuration on flow and energy transport in a randomly packed bed setup has been investigated. Based on the desirable properties of the packed bed, such as low pressure drop, high heat transfer coefficient, increased surface area, and high catalyst inventory, the overall performance of the investigated pellet shapes is analyzed. The foam ring with the aspect ratio of 2.5 and ϕ = 0.45 mm, ε = 0.82 has been identified as optimal under the investigated operating conditions 250 < ReP < 2250, which is confirmed by pressure drop and heat transfer experiments.

Radial heat transport in a fixed-bed reactor made of metallic foam pellets: Experiment and particle-resolved computational fluid dynamics

Open-cell metallic foams in the shape of pelletized catalysts are regarded as potential catalyst substrates for the application in fixed-bed reactors. This work reports an experimental study and a detailed Computational Fluid Dynamics (CFD) model to investigate the heat transfer performance of a fixed-bed reactor made of open-cell metallic foam pellets. The steady-state heat transfer behavior of a hot gas flowing through such a packed bed under wall-cooled conditions was examined. The proposed CFD model is in line with the particle-resolved CFD (PRCFD) approach that accounts explicitly for the random packing structure, so that the transport processes in the interstitial regions are fully resolved. The momentum and energy transports inside the highly porous foam particles are considered by closure equations based on the porous-media model. The Rigid Body Dynamics (RBD) method is adopted to create the packing geometry. The axial temperature and the pressure drop obtained by the CFD simulations show good agreement with experimental data. To evaluate the thermal performance, effective heat transport parameters in a packed bed such as the effective radial thermal conductivity and the apparent wall-fluid heat transfer coefficient are determined, with the aid of a 2D pseudo-homogenous plug-flow reactor model. The correlations for heat transport characteristics as a function of particle Reynolds number for the metallic foam packed bed are also presented.

Performance analysis of nuclear reactor core loaded with Accident-Tolerant Fuel: Mo/Cr metallic microcell UO2 pellets and CrAl coating

This paper presents a performance analysis of a commercial pressurized water reactor (PWR) core loaded with accident-tolerant fuel (ATF) containing Mo/Cr metallic microcell UO2 pellets and a CrAl coating on the cladding. Metallic microcell UO2 pellets using additive materials, such as Mo and Cr, with coated cladding have been developed by the Korea Atomic Energy Research Institute (KAERI) for an OPR-1000 reactor. As demonstrated by the fuel pellet developed at KAERI, a metallic microcell UO2 pellet can increase the thermal conductivity of fuel pellets by forming a metallic film that encapsulates the UO2 to connect the metallic microcell and UO2 pellets; however, there has been no systematic core performance and safety analysis of the core with ATFs. In this study, core analysis with ATFs was conducted from a neutronic perspective. 1) The fuel assembly (FA) containing Mo/Cr metallic microcell UO2 pellets was analyzed using the lattice code STREAM developed by Ulsan National Institute of Science and Technology in terms of the Mo depletion chain and the impact of resonance treatment. 2) The initial and equilibrium cores were analyzed using STREAM/RAST-K 2.0 with respect to the impact of the additives and CrAl coating on the cycle length, power peaking, and fuel temperatures, etc. The reductions in the equilibrium core cycle length were 61, 44, and 65 effective full power days for each material type. 3) Finally, a rod ejection accident (REA) analysis was performed on the core using a Mo metallic microcell UO2 pellet and CrAl-coated ATF. Moreover, the maximum fuel centerline temperature of the ATF core was determined to be approximately 200 ℃ lower than that of the reference UO2 core. Furthermore, the presence of additional thermal margins in ATF cores for steady-state and accident transient scenarios was verified through a systematic neutronic analysis, and future studies will focus on the optimization of the ATF-loaded core by exploiting the extra margins achieved by ATFs and increasing the cycle length.

Influence of Foam Morphology on Flow and Heat Transport in a Random Packed Bed with Metallic Foam Pellets-An Investigation Using CFD.

Open-cell metallic foams used as catalyst supports exhibit excellent transport properties. In this work, a unique application of metallic foam, as pelletized catalyst in a packed bed reactor, is examined. By using a wall-segment Computational Fluid Dynamics (CFD) setup, parametric analyses are carried out to investigate the influence of foam morphologies (cell size and porosity ) and intrinsic conductivity on flow and heat transport characteristics in a slender packed bed made of cylindrical metallic foam pellets. The transport processes have been modeled using an extended version of conventional particle-resolved CFD, i.e., flow and energy in inter-particle spaces are fully resolved, whereas the porous-media model is used for the effective transport processes inside highly-porous foam pellets. Simulation inputs include the processing parameters relevant to Steam Methane Reforming (SMR), analyzed for low ( and high ( flow regimes. The effect of foam morphologies on packed beds has shown that the desired requirements contradict each other, i.e., an increase in cell size and porosity favors the reduction in pressure drop, but, it reduces the heat transfer efficiency. A design study is also conducted to find the optimum foam morphology of a cylindrical foam pellet at a higher , which yields = 0.45, = 0.8. Suitable correlations to predict the friction factor and the overall heat transfer coefficient in a foam-packed bed have been presented, which consider the effect of different foam morphologies over a range of particle Reynolds number, .

Oxidative damage in metal fragment-embedded Sprague-Dawley rat gastrocnemius muscle

Injuries suffered in armed conflicts often result in wounds with embedded metal fragments. Standard surgical guidance has been to leave fragments in place except under certain circumstances; meaning that individuals may carry these retained fragments for their lifetime. Because of advancements in weapon design and the use of improvised explosive devices, the list of metals that could be found in a wound is extensive. In most cases the toxicological properties of these metals when embedded in the body are not known. To assess the potential damage embedded metals may cause to surrounding tissue, we utilized a rodent model to investigate the effect of a variety of military-relevant metals on markers of oxidative damage. The metals tested included tungsten, nickel, cobalt, iron, copper, aluminum, lead, and depleted uranium. Herein we report our findings on creatine kinase activity, lipid and protein oxidation, total antioxidant capacity, and glutathione levels in gastrocnemius homogenates from Sprague-Dawley rats surgically implanted with metal pellets for periods up to 12 months. Not all embedded metals affected the measured markers equally. However, metal-associated effects were seen at various times for muscle and serum creatinine levels, protein oxidation, total antioxidant capacity, and glutathione levels. No metal-induced effects on lipid peroxidation were observed. Taken together, these data suggest that subtle oxidative damage may be occurring in the muscle surrounding an embedded metal and indicates the need for medical surveillance of those individuals wounded by metal shrapnel.

Analysis of pellet-to-cladding gap closure for a metallic micro-cell pellet under normal operating conditions

To reduce fission gas release under both accident conditions and normal operation, Korea Atomic Energy Research Institute has developed a metallic micro-cell pellet following the 2011 Fukushima accident. One concern, however, about the metallic micro-cell pellet is that due to the presence of metallic wall that reduces both temperature and gas release, its capability of higher gas retention could result in increased gaseous swelling, leading to earlier pellet-to-cladding gap closure than the conventional UO 2 pellet. To analyze and compare the gap closure in two fuel rods in which two kinds of pellets, UO 2 and metallic micro-cell, are loaded into each of the two identical Zr claddings, we developed a model to estimate gaseous swelling in the two pellets. Then considering mainly different gaseous swelling and thermal expansion by different temperature profiles in the two pellets, we compared the pellet-to-cladding gaps as a function of burnup for the case where they would be irradiated with the same constant linear power of 30 kW/m up to 60 MWd/kgU. Due to both reduced gaseous swelling and lower thermal expansion, gap closure in the fuel rod loaded with the metallic micro-cell pellet is expected to be delayed by 6–16 MWd/kgU compared with the one loaded with the UO 2 pellet, implying pellet-cladding mechanical interaction occurrence would also be postponed by the same degree. We note that the result of this approach is preliminary until confirmed by measured data from metallic micro-cell pellets irradiated up to high burnup. • Higher gas-retention capability in the metallic micro-cell pellet could lead to earlier pellet-to-cladding gap closure than the UO 2 pellet. • Despite the higher gas-retention capability, gaseous swelling in the metallic micro-cell pellet would be reduced by its lower temperature. • Pellet-to-cladding gap closure in the metallic micro-cell pellet could be delayed by 6–16 MWd/kgU compared with the UO 2 pellet.

3D-Printed Labs: A Force Table and Simple Pulleys

In this paper we explain how to build a very sensitive force table using 3D-printed parts. The key component of this apparatus is a simple sensitive pulley that, together with the other components, can be printed in one day (one hour per pulley, 17 hours for a complete three-pulleys table) at the cost of 160 g of plastic filament. This force table can be used in a vertical position on a whiteboard for an all-class discussion or in a horizontal position for personal or group usage. The design includes calibrated mass hangers that use coins or small metal pellets as weights. To view the files, go to https://www.thingiverse.com/thing:5019204.

Fundamental Study of Electrolysis of MgO in MgF2 - LiF - KCl Molten Salt Using Cu Cathode

For the commercial production of magnesium (Mg) metal using the electrolytic method, anhydrous magnesium chloride (MgCl2) is used as a feedstock. However, preparation of anhydrous MgCl2 is energy-intensive and toxic chlorine (Cl2) gas is generated during electrolysis. In order to resolve these problems, a novel molten salt electrolysis of magnesium oxide (MgO) using copper (Cu) cathode was investigated in this study. The effect of the electrolysis temperature, the size of the Cu metal pellets used for the cathode, the concentration of Mg in the Mg – Cu alloy, and the cathodic current density on the current efficiency were investigated. In addition, the reaction between the Mg – Cu alloy cathode and the alumina (Al2O3) crucible containing the Mg alloy during the electrolysis was analyzed. In the experiments, the electrolysis of MgO was conducted in a magnesium fluoride (MgF2) – lithium fluoride (LiF) – potassium chloride (KCl) molten salt using Cu cathode and carbon (C) anode by applying current in the range of 1.42 – 2.15 A at 1043 – 1173 K for 9.50 – 27.5 h in an argon gas atmosphere. After the electrolysis, the Mg – Cu alloys with a mixture of Cu2Mg and Cu (Mg) were obtained with 87.8 – 92.0 % current efficiency under certain conditions. Therefore, it was demonstrated that the green and effective electrolytic Mg production method using MgO, developed in this study, is feasible.

Volatilization and condensation behavior of magnesium vapor during magnesium production via a silicothermic process with magnesite

The condensation behavior of magnesium vapor produced by metal Mg or pellets for magnesium production is investigated at heat source temperatures of 1173–1473 K under vacuum. The possibility of reduction of magnesite in vacuum was analyzed by means of thermodynamics. The results indicate that the thermal motion of magnesium is violent, and the volatilization rate increased with high heat source temperature, the results accord with Maxwell's velocity distribution law. Magnesium vapor condensation products were obtained with flake and powder macromorphologies, where the flake products accounted for more than 80% (in mass). Scanning electron microscopic analysis revealed that the main factor affecting the magnesium vapor condensed particles was the vapor pressure, which was determined by temperature and reaction. The end condensation temperature was between 528.1 and 637.1 K when the heat source temperature was 1173–1473 K. Increasing the temperature gradient decreases the condensation temperature range. X-ray diffraction results showed that the magnesium condensation products were more crystalline at lower vapor pressure and a small temperature gradient. The presence of Ca2SiO4 in the reduction slag indicated the occurrence of the reduction reaction. The experimental results from pellets for magnesium production were consistent with those involving Mg metal.

Spectroscopic and Spectrometric Approaches for Assessing the Composition of Embedded Metals in Tissues.

Many medical devices contain metals that interface with the body. Additionally, embedded metal fragments from military wounds are typically not removed, to avoid the risk of morbidity associated with invasive surgery. The long-term health consequences of many of these materials are not thoroughly understood. To this end, we have exposed rats for up to one year to implanted single-element metal pellets of any one of Al, Co, Cu, Fe, Ni, Pb, Ta, or W. Various tissues were harvested and flash frozen for analysis of their metal distribution. We discuss approaches to most thoroughly and reliably evaluate the distribution of metal in these tissues. The path to the most appropriate analytical technique took us through extensive examination of the tissues using scanning electron microscopy with energy dispersive X-ray spectroscopy (XPS), X-ray photoelectron spectroscopy (XPS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Though any one of these methods is highly relied upon in surface chemistry analysis, LA-ICP-MS alone showed presence of metal in the tissue. This information will help build robust methods to bridge the gap in our understanding of biosolubility and distribution of embedded metal throughout the body.

Effect of embedded metal fragments on urinary metal levels and kidney biomarkers in the Sprague-Dawley rat.

Wounds with embedded metal fragments are an unfortunate consequence of armed conflicts. In many cases the exact identity of the metal(s) and their long-term health effects, especially on the kidney, are not known. The aim of this study was to quantitate the urinary levels of metals solubilized from surgically implanted metal pellets and to assess the effect of these metals on the kidney using a battery of biomarker assays. Using a rodent model system developed in our Institute to simulate embedded fragment injuries, eight metals considered likely components of an embedded fragment wound were individually implanted into the gastrocnemius muscle of male Sprague-Dawley rats. The rats were followed for 12 months post-implantation with urine collected prior to surgery then at 1-, 3-, 6-, 9-, and 12-months post-implantation to provide a within-subjects cohort for examination. Urinary metal levels were determined using inductively coupled plasma-mass spectrometry and urinary biomarkers assessed using commercially available kits to determine metal-induced kidney effects. With few exceptions, most of the implanted metals rapidly solubilized and were found in the urine at significantly higher levels than in control animals as early as 1-month post-implantation. Surprisingly, many of the biomarkers measured were decreased compared to control at 1-month post-implantation before returning to normal at the later time points. However, two metals, iron and depleted uranium, showed increased levels of several markers at later time points, yet these levels also returned to normal as time progressed. This study showed that metal pellets surgically implanted into the leg muscle of Sprague-Dawley rats rapidly solubilized with significant levels of the implanted metal found in the urine. Although kidney biomarker results were inconsistent, the changes observed along with the relatively low amounts of metal implanted, suggest that metal-induced renal effects need to be considered when caring for individuals with embedded metal fragment wounds.

Metal distribution patterns in tissues from implanted Sprague-Dawley rats

Background: Injuries with fragments of embedded metal are a common occurrence in armed conflicts. Unfortunately, the list of metals encountered on the modern battlefield are practically endless while the short- and long-term health effects, especially when embedded as in a shrapnel wound, are not well understood. One of the major concerns with these types of injuries is the solubilization of the embedded metal and the translocation and deposition to various organs of the body. Methods: Using a rodent model system developed in our laboratory to assess the health effects of embedded metal fragments, we surgically implanted metal pellets into the gastrocnemius muscles of male Sprague-Dawley rats. Test metals were chosen from a list promulgated by the U.S. Department of Defense as “metals of concern” with respect to embedded fragment wounds and included tungsten, nickel, cobalt, iron, copper, aluminum, lead, and depleted uranium. Tantalum was used as a control metal. Cohorts of the metal-implanted rats were humanely euthanized at 1, 3, 6, and 12-months post-implantation and a variety of tissues collected and analyzed for metal content using inductively coupled plasma-mass spectrometry. Results: With few exceptions, the embedded metal fragments eventually released solubilized metal ions, with the metals deposited in numerous tissues in the rats. Not all of the embedded metals localized to all tissues at significant levels. Copper, iron, and aluminum were not found in statistically significant levels, versus control, in any of the tissues analyzed. The other metals tested all appeared in elevated levels in the kidney which is not surprising since previous research has shown that they are also excreted in the urine at appreciable amounts. Tungsten and nickel were found in only a small number of tissues, tungsten in spleen, and nickel in liver and testes. Cobalt, lead, and depleted uranium showed the widest distribution with significant levels in liver, spleen, testes, lung, tibia, fibula, and femur. Conclusion: In this study, we showed that embedded metal fragments, such as those suffered in a shrapnel wound, could solubilize and metals become deposited in tissues far from the original site of implantation. Tissue deposition was metal-specific and many of the metals were found to cross the blood-testes barrier and were also found in bone. Since standard surgical guidance recommends leaving embedded fragments in place except for certain circumstances, this report will expand the understanding of tissue deposition of the solubilized metals and will hopefully aid healthcare professionals in developing long-term treatment strategies for dealing with these types of wounds.

Effect of Using Rice Husk Char as an Additive on Phosphate Recovery from Swine Wastewater by Magnesium Metal Corrosion

The recovery of phosphate from swine wastewater is highly significant in order to alleviate eutrophication in aquatic ecosystems, and the increasing scarcity in phosphorus resources. This study reports on a strategy to recover phosphate from swine wastewater using rice husk char as an additive via magnesium metal corrosion. The results demonstrated high levels of recovery efficiency at relatively low cost. When the mass ratio of rice husk char to magnesium was 2:1, the pH of this solution increased to 9.75, and the phosphate recovery efficiency from real swine wastewater reached 96.80% at a Reynolds number of 13931 without aeration. Evaluation of economic feasibility revealed that the proposed method was $0.79 kg−1 of PO4-P. Approximately 57.98% of the cost may be saved compared with the use of magnesium metal pellets coupled with graphite pellets.

Time-course analysis of the effect of embedded metal on skeletal muscle gene expression.

As a consequence of military operations, many veterans suffer from penetrating wounds and long-term retention of military-grade heavy metal fragments. Fragments vary in size and location, and complete surgical removal may not be feasible or beneficial in all cases. Increasing evidence suggests retention of heavy metal fragments may have serious biological implications, including increased risks for malignant transformation. Previous studies assessed the tumorigenic effects of metal alloys in rats, demonstrating combinations of metals are sufficient to induce tumor formation after prolonged retention in skeletal muscle tissue. In this study, we analyzed transcriptional changes in skeletal muscle tissue in response to eight different military-relevant pure metals over 12 mo. We found that most transcriptional changes occur at 1 and 3 mo after metal pellets are embedded in skeletal muscle and these effects resolve at 6 and 12 mo. We also report significant immunogenic effects of nickel and cobalt and suppressive effects of lead and depleted uranium on gene expression. Overall, skeletal muscle exhibits a remarkable capacity to adapt to and recover from internalized metal fragments; however, the cellular response to chronic exposure may be restricted to the metal-tissue interface. These data suggest that unless affected regions are specifically captured by biopsy, it would be difficult to reliably detect changes in muscle gene expression that would be indicative of long-term adverse health outcomes.