Formation Of Deposits Research Articles

Electro-Coloring Mechanism of Aluminum Anodic Oxides in Tin-Based Electrolytes

A method for accurately determining the chemical composition of deposits at the bottom of pores during the electrocoloring (e-coloring) of aluminum anodic oxide (AAO) layers in tin-based solutions is developed. The aluminum samples were AC e-colored after DC sulfuric anodization. Free-standing, tin e-colored aluminum oxide film was obtained by selective dissolution of the metallic aluminum from the AAO in copper chloride solution to access the deposit directly at the bottom of the pore. This allowed us to conduct XPS analysis directly on the deposits at pore bottoms without any interference from the base material or insulating barrier layer. The results revealed the presence of a mixture of tin oxide and metal in the deposits, which were richer in oxide content. Furthermore, a cyclic voltammetry experiment mimicking real polarization conditions during AC conditions was optimized and used to gain a deeper understanding of the electrochemical reactions that occur during AC electrocoloring. The comparison of CV results in tin-free and tin-containing electrolytes indicated that the tin deposited during a cathodic cycle is oxidized in the anodic cycle. The formation of tin-based deposits radically changed the CV behavior. The XPS and cyclic voltammetry results consistently show that the deposits formed during e-coloring comprised a mixture of metallic and oxidic tin species richer in oxide content.

Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental redox processes

Understanding changes in redox conditions in the Earth's geological record is fundamental to unravelling some of the major events of our planet's history, such as the Great Oxidation Event (G.O.E.), biological changes through time related to mass extinctions, or the formation of ore deposits for primordial metal resources. Rocks from uranium deposits are ideal candidates to examine the coupled isotopic fractionation of Tl, Mo and U, as they are fundamentally caused by redox processes, occur in a wide variety of geological settings throughout much of geological history (from about 3 Ga), and result from the interplay between fluids and rocks of variable redox states. Herein we measure δ97Mo (−10.2 to +6.1 ‰), ε205Tl (−9.5 to +5.0 ε-units), and δ238U (−0.72 to 0.30 ‰) for 34 samples from granite-related, intrusive, metamorphic, and Proterozoic unconformity related U deposits. Collectively, these results suggest: 1) in metamorphic and unconformity-related contexts, samples with decreasing ε205Tl values also have decreasing δ238U values, indicative of change in redox conditions, 2) ε205Tl values in the sulfide-rich samples likely reflect the affinity of 205Tl for these minerals, 3) Tl undergoes significant isotopic fractionation during the reduction of U-bearing fluids to precipitate uraninite, and 4) Tl isotopes do not fractionate during secondary remobilization of elements within these systems, and thus retain a record of the conditions of formation, whereas Mo isotopes are heavily fractionated by secondary remobilization. We suggest that the study of U, Mo, and Tl isotopes in U-ore deposits conveys new information related to building blocks of life on Earth and shows great potential for the study of past oxygenation events, thus potentially allowing us to reconstruct the geological and chemical history of our planet.

Scalable Customization of Crystallographic Plane Controllable Lithium Metal Anodes for Ultralong-Lasting Lithium Metal Batteries.

A formidable challenge to achieve the practical applications of rechargeable lithium (Li) metal batteries (RLMBs) is to suppress the uncontrollable growth of Li dendrites. One of the most effective solutions is to fabricate Li metal anodes with specific crystal plane, but still lack of a simple and high-efficient approach. Herein, a facile and controllable way for the scalable customization of polished Li metal anodes with highly preferred (110) and (200) crystallographic orientation (donating as polished Li(110) and polished Li(200), respectively) by regulating the times of accumulative roll bonding, is reported. According to the inherent characteristics of polished Li(110)/Li(200), the influence of Li atomic structure on the electrochemical performance of RLMBs is deeply elucidated by combining theoretical calculations with relative experimental proofs. In particular, a polished Li(110) crystal plane is demonstrated to induce Li+ uniform deposition, promoting the formation of flat and dense Li deposits. Impressively, the polished Li(110)||LiFePO4 full cells exhibit unprecedented cycling stability with 10000 cycles at 10 C almost without capacity degradation, indicating the great potential application prospect of such textured Li metal. More valuably, this work provides an important reference for low-cost, continued, and large-scale production of Li metal anodes with highly preferred crystal orientation through roll-to-roll manufacturability.

Contrasting magma chemistry in the Candelaria IOCG district caused by changing tectonic regimes

Iron oxide-copper-gold (IOCG) deposits are a vital source of copper and critical elements for emerging clean technologies. Andean-type IOCG deposits form in continental arcs undergoing extension, and they have a temporal relationship with magmatism although they do not exhibit a close spatial relation with the causative intrusions. The processes required to form IOCG deposits and their potential connections to iron oxide–apatite (IOA)-type mineralization remain poorly constrained, as well as the characteristics of magmatism linked to both deposit types. Here we combine zircon U–Pb geochronology with zircon trace element geochemistry of intrusive rocks associated with the Candelaria deposit, one of the world’s largest IOCG deposits, to unravel distinctive signatures diagnostic of magmatic fertility. Our results reveal a marked transition in the geochemistry of intrusions in the Candelaria district, characterized by changes in the redox state, water content and temperature of magmas over time. The oldest magmatic stage (~ 128–125 Ma), prior to the formation of the Candelaria deposit, was characterized by zircon Eu/Eu* ratios of 0.20–0.42, and redox conditions of ΔFMQ − 0.4 to + 1.0. The earliest magmatic stage related to the formation of Fe-rich mineralization at Candelaria (118–115 Ma) exhibits low zircon Eu/Eu* ratios (0.09–0.18), low oxygen fugacity values (ΔFMQ ~− 1.8 to + 0.2) and relatively high crystallization temperatures. In contrast, the youngest stage at ~ 111–108 Ma shows higher zircon Eu/Eu* (~ 0.37–0.69), higher oxygen fugacity values (ΔFMQ ~ + 0.4 to + 1.3) and a decrease in crystallization temperatures, conditions that are favorable for the transport and precipitation of sulfur and chalcophile elements. We conclude that Candelaria was formed through two distinct ore-forming stages: the first associated with a reduced, high temperature, water-poor magma developed under a low tectonic stress, followed by a more oxidized, water-rich, and low temperature magmatic event related to a compressional regime. The first event led to Fe-rich and S-poor IOA-type mineralization, while the second event with geochemical signatures similar to those of porphyry copper systems, generated the Cu- and S-rich mineralization. This late stage overprinted preexisting IOA mineralization resulting in the formation of the giant Candelaria IOCG deposit.

Design and experimental study of a 300 We class combustion-driven high frequency free-piston Stirling electric generator

Portable electric power generator with a power level of several hundred Watts plays an important role in outdoor activities, emergency relief and tactical power supply. As an external-combustion heat engine with outstanding heat source adaptability, free-piston Stirling generator (FPSG) owns attractive advantages of quietness, high thermal efficiency, and high reliability. This paper proposes a novel ultra-high frequency (UHF) FPSG-based portable power supply system driven by a diesel porous media evaporative combustor (PMEC). An experimental setup was designed and built based on the quasi-one-dimension thermoacoustic impedance matching of the FPSG and three-dimension thermal coupling of steady combustion and alternating flow between FPSG and combustor. The fundamental operating characteristics of the system were investigated in terms of combustion powers and electric loads. Preliminary experimental results show that a maximum output electric power of 350 We at a heating temperature of 875 K and a maximum fuel-to-electric efficiency of 11.98 % were obtained. Computational fluid dynamics (CFD) simulations were employed to delve into the intricate combustion and heat transfer processes, unveiling the formation of carbon deposits and confirming the efficacy of cyclone holes in reducing carbon deposition. This pioneering exploration of 130 Hz UHF and evaporative-combustion coupled heat transfer successfully showcases the feasibility of constructing a high-specific-power FPSG-based portable power system.

Enhanced Catalytic Hydrogenation of Olefins in Sulfur-Rich Naphtha Using Molybdenum Carbide Supported on γ-Al2O3 Spheres under Steam Conditions: Simulating the Hot Separator Stream Process.

Spheres comprising 10 wt.% Mo2C/γ-Al2O3, synthesized through the sucrose route, exhibited unprecedented catalytic activity for olefin hydrogenation within an industrial naphtha feedstock that contained 23 wt.% olefins, as determined by supercritical fluid chromatography (SFC). The catalyst demonstrated resilience to sulfur, exhibiting no discernible deactivation signs over a tested 96 h operational period. The resultant hydrogenated naphtha from the catalytic process contained only 2.5 wt.% olefins when the reaction was conducted at 280 °C and 3.44 × 106 Pa H2, subsequently blended with Athabasca bitumen to meet pipeline specifications for oil transportation. Additionally, the carbide catalyst spheres effectively hydrogenated olefins under steam conditions without experiencing any notable hydrogenation in the aromatics. We propose the supported carbide catalyst as a viable alternative to noble metals, serving as a selective agent for olefin elimination from light petroleum distillates in the presence of steam and sulfur, mitigating the formation of gums and deposits during the transportation of diluted bitumen (dilbit) through pipelines.

Blocking the passivation reaction via localized acidification and cation selective interface towards highly stable zinc anode

The variations of pH triggers either the formation of zinc sulfate hydroxide (ZSH) or the hydrogen evolution reaction (HER), leading to unsatisfactory zinc anode efficiency. In order to establish a balanced approach that suppresses the HER while creating an acidic environment to eliminate ZSH formation, this study introduces an environmentally friendly chelating additive, tetrasodium iminodisuccinate (IDS), into the ZnSO4 electrolyte. This additive serves to generate a localized acidic environment and a cation-selective surface barrier. The preferentially adsorbed IDS anions create a water-poor interface and engage in synergistic regulation of cation and anion via electrostatic effects, promoting smooth Zn deposition and reducing by-product formation. Additionally, IDS can strongly interact with Zn2+ and adapt to pH variations, thereby providing a stable environment that mitigates side reactions. Unlike sacrificial additives, IDS demonstrates stability under test conditions, resulting in a truly reversible and stable electrolyte system. The implementation of this multifunctional additive results in a prolonged lifespan of metallic Zn, reaching 2548 h, and a promoted coulombic efficiency of 99.5 %. Furthermore, the improved stability of Zn anodes is observed in Zn//LiFePO4 cells, exhibiting the capacity retention of 97.0 % over 800 cycles. This strategy opens up a new pathway for enhancing the stability and reversibility of Zn anodes.

Plugging of pipes by cohesive particles. Computed tomography investigation and theoretical analysis

Flow regimes leading to clogging of pipes exist for most multiphase flows with cohesive particles. Although plugging is critical in many industrial and medical applications, there are few records describing the details of the process. To address the problem, we conduct a computed tomography (CT) study of plugging in a cohesive ice slurry. We run experiments for ice concentration of 15%, Re∼3500, particle size 0.2-0.4 mm, and their surface energy ∼150 mJ/m2. The CT scans, combined with experimental logs of the main flow parameters, revealed the formation of deposits around the orifice inserted into the pipe, with a complete blockage formed downflow the orifice. The deposition efficiency of ice was relatively low ∼ 10−3. Reproducing the experimental deposition efficiency with the Lagrangian CFD model, we extracted the probability of particle capture at the orifice, which was about 0.5%. The simulation results illustrated how inter-particle interactions hindered the plugging.

Electron-induced deposition using Fe(CO)4MA and Fe(CO)5 - effect of MA ligand and process conditions.

The electron-induced decomposition of Fe(CO)4MA (MA = methyl acrylate), which is a potential new precursor for focused electron beam-induced deposition (FEBID), was investigated by surface science experiments under UHV conditions. Auger electron spectroscopy was used to monitor deposit formation. The comparison between Fe(CO)4MA and Fe(CO)5 revealed the effect of the modified ligand architecture on the deposit formation in electron irradiation experiments that mimic FEBID and cryo-FEBID processes. Electron-stimulated desorption and post-irradiation thermal desorption spectrometry were used to obtain insight into the fate of the ligands upon electron irradiation. As a key finding, the deposits obtained from Fe(CO)4MA and Fe(CO)5 were surprisingly similar, and the relative amount of carbon in deposits prepared from Fe(CO)4MA was considerably less than the amount of carbon in the MA ligand. This demonstrates that electron irradiation efficiently cleaves the neutral MA ligand from the precursor. In addition to deposit formation by electron irradiation, the thermal decomposition of Fe(CO)4MA and Fe(CO)5 on an Fe seed layer prepared by EBID was compared. While Fe(CO)5 sustains autocatalytic growth of the deposit, the MA ligand hinders the thermal decomposition in the case of Fe(CO)4MA. The heteroleptic precursor Fe(CO)4MA, thus, offers the possibility to suppress contributions of thermal reactions, which can compromise control over the deposit shape and size in FEBID processes.

Ferric sludge derived pyrolyzed-hydrochar supported iron catalysts for catalytic cracking of toluene

Effective treatment of ferric sludge in an eco-friendly method is key to the feasibility of Fenton technology in pollution treatment, contributing to the realization of the “dual-carbon” strategic objectives. In this study, Fe-loaded pyrolyzed-hydrochar catalysts were prepared using simple one-pot hydrothermal carbonization (HTC) method with ferric sludge as the precursor, which greatly reduced the energy and time consumption on the preparation of the sludge derived catalyst. At 800 °C with a reaction time of 20 min, all catalysts showed high toluene removal performance (>60 %) and produced H2-rich syngas (H2 > 90 %). In particular, the catalyst prepared by HNO3-assisted HTC (HNC) presented the highest toluene removal efficiency and H2 yield, 77.52 ± 3.36 % and 11.12 ± 0.66 mol%, respectively. Additionally, the sources of carbon deposits and the interaction between the active site and carbon deposits were analyzed in detail by DFT to reveal the catalytic activity and deactivation mechanism of catalyst. The results showed that the adsorption energy of C generated from methyl on different Fe phases was lowest (the adsorption energy of C was −8.79 eV for Fe, −5.28 eV for Fe2O3, and −4.70 eV for Fe3O4), suggesting that the adsorption of C on catalyst was the main reason for the formation of carbon deposits. The lowest adsorption energy of the metallic Fe phase for C indicated that Fe0 was coated by carbon deposits during toluene catalytic cracking, which hampered catalytic activity. These results are of great significance for optimizing the preparation of Fe-loaded carbonaceous catalysts and the regulation of Fe active phase.

Simulating taphonomic processes on teeth: The impact of sediment pressure and thermal alteration on dental microwear

Dietary reconstructions based on dental microwear methodologies may be limited due to the various taphonomic processes that affect the formation of archaeological deposits. These limitations are primarily affected by two issues: 1) taphonomic alterations occurring over dental microwear patterns which mimic dietary signals and can lead to confusion in quantifying these signals, and 2) the exclusion of teeth due to structural damage caused by taphonomic processes, resulting in a reduction of the sample size. Thus, it is necessary to understand how taphonomic processes impact teeth to avoid biases in dietary reconstructions and improve the validity of their interpretations. Under these considerations, we conducted two experiments: one involving the simulation of sediment pressure, and the other focusing on thermal alterations. A hydraulic press and a muffle furnace were used for these purposes. The results of the experiments allowed us to characterise the alterations produced by abrasion caused by sediment pressure, enabling differentiation from dietary signals (scratches, pits, and gouges) and excluding them from dental microwear analyses. However, the thermal alteration experiment showed that this process does not produce significant effects, and even carbonized teeth retain dental microwear, making them appropriate for dietary reconstructions. Additionally, a comparison of archaeological teeth from level IIIb of Teixoneres Cave (Moià, Barcelona) was conducted, confirming the inferences drawn from the experimental results. This research highlights the importance of conducting such studies to better understand the impact of taphonomic processes on dental microwear, which is crucial for accurate dietary and palaeoecological interpretations.

Quantum-chemistry-computing and experimental development of a new n-alkenyl amino propionic and imino di-propionic acids-based gum inhibitor for gasoline

We present the quantum mechanics-based understanding about the formation of gums deposits in order to design, and then carry out the experimental synthesis of a detergent-dispersant (DD) gasoline additive base n-alkenyl imino di-propionic acid, obtained in mixture with its precursor base n-alkenyl amino propionic acid, aimed both to inhibit gums deposits within internal-combustion engines and maintain in suspension gums inside gasoline. Density Functional Theory reveals the cohesion among gums agglomerates is mediated mainly through dispersion forces, that is, gums form supramolecular complexes; likewise, their affinity for oxidized metallic surfaces is predominantly due also to the dispersion forces, but intensified through the linking of the gums' oxygens by the exposed metallic-surface irons, which is quantum driven to maximize irons spin through completing the truncated oxygen octahedral coordination, so providing to the gums' adsorption a mixed chemisorption/physisorption character. Additionally, carbons from double bonds C=C or from aromatic rings, as well as aminic hydrogens, contribute by means of weak semicovalent bonds to the gums’ chemisorption too. We take advantage of this acquired knowledge to outline a superior coordination chemistry to that of gums for the above deposits inhibitor, lying on the capability to form either trinuclear-tridentate or binuclear-bidentate surface complexes, reinforced moreover by a six-membered chelate ring containing an iron cation. The additive was lab synthesized by means of an industrial-scale residues-less process, and characterized through 1H and 13C nuclear magnetic resonance along with infrared spectroscopy. The detergent performance, experimentally tested within the intake valve of a single-cylinder engine, shows that the DD additive inhibits up to 93.3% of the gums deposition.

Lunar regolith water ice simulation method and characterization

The exploration of lunar water resources has always been a cutting-edge topic in human space exploration. This paper presents a method for gas deposition and ice formation to simulate the mixture of ice and regolith in lunar polar shadowed regions. Following the principles of “physical structure equivalence and environmental parameter approximation,” based on the principle of water molecule deposition and adsorption in a cold trap environment, water ice is converted into water vapor by raising the temperature in a vacuum environment. Then, water molecules deposit and adsorb on the surface of dry, low-temperature mineral particles, forming an ice film under the action of the cold trap capture principle. The morphology and occurrence status of the particle surface ice film has been obtained through microscopic characterization of the samples in a cold environment. Vacuum pressure monitoring equipment is used to verify the pressure changes of water during the sublimation and deposition, and the phase diagram of water is analyzed to understand its state changes within the simulated setup. Samples are retrieved from a high-purity nitrogen glove box, and their water content is verified using thermogravimetric analysis (TGA). The effectiveness of the proposed lunar regolith simulation method is validated through macroscopic and microscopic approaches. This method provides high-fidelity samples for lunar water resource utilization, scientific exploration, and payload development on the Moon.

Investigating Salt Precipitation in Continuous Supercritical Water Gasification of Biomass

The formation of solid deposits in the process of supercritical water gasification (SCWG) is one of the main problems hindering the commercial application of the process. Seven experiments were conducted with the grass Reed Canary Grass with different preheating temperatures, but all ended early due to the formation of solid deposits (maximum operation of 3.8 h). The position of solid deposits in the lab plant changed with the variation in the temperature profile. Since the formation of solid deposits consisting of salts, coke, and corrosion products is a severe issue that needs to be resolved in order to enable long-time operation, inner temperature measurements were conducted to determine the temperature range that corresponds with the zone of solid formation. The temperature range was found to be 400 to 440 °C. Wherever this temperature was first reached solid deposits occurred in the system that led to blockage of the flow. Additional to the influence of the temperature, the influence of the flow direction (up-flow or down-flow) on the operation of the continuous SCWG plant was examined. If salts are not separated from the system sufficiently, up-flow reactors should be avoided because they amplify the accumulation of solid deposits leading to a shortened operation time. The heating concept coupled with the salt separation needs to be redesigned in order to separate the salts before entering the gasification reactors. Outside of the determined temperature zone no deposition was visible. Thus, even though the gasification efficiency was low it could be shown that the operation was limited to the deposits forming in the heating section and not by incomplete gasification in the reactor where T > 600 °C.

A sponge-like nanofiber melatonin-loaded scaffold accelerates vascularized bone regeneration via improving mitochondrial energy metabolism

Electrospun nanofibers have been widely employed in bone tissue engineering for their ability to mimic the micro to nanometer scale network of the native bone extracellular matrix. However, the dense fibrous structure and limited mechanical support of these nanofibers pose challenges for the treatment of critical size bone defects. In this study, we propose a facile approach for creating a three-dimensional scaffold using interconnected electrospun nanofibers containing melatonin (Scaffold@MT). The hypothesis posited that the sponge-like Scaffold@MT could potentially enhance bone regeneration and angiogenesis by modulating mitochondrial energy metabolism. Melatonin-loaded gelatin and poly-lactic-acid nanofibers were fabricated using electrospinning, then fragmented into shorter fibers. The sponge-like Scaffold@MT was created through a process involving homogenization, low-temperature lyophilization, and chemical cross-linking, while maintaining the microstructure of the continuous nanofibers. The incorporation of short nanofibers led to a low release of melatonin and increased Young's modulus of the scaffold. Scaffold@MT demonstrated positive biocompatibility by promoting a 14.2 % increase in cell proliferation. In comparison to the control group, Scaffold@MT significantly enhanced matrix mineralization by 3.2-fold and upregulated the gene expression of osteoblast-specific markers, thereby facilitating osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs). Significantly, Scaffold@MT led to a marked enhancement in the mitochondrial energy function of BMMSCs, evidenced by elevated adenosine triphosphate (ATP) production, mitochondrial membrane potential, and protein expression of respiratory chain factors. Furthermore, Scaffold@MT promoted the migration of human umbilical vein endothelial cells (HUVECs) and increased tube formation by 1.3 times compared to the control group, accompanied by an increase in vascular endothelial growth factor (VEGFA) expression. The results of in vivo experiments indicate that the implantation of Scaffold@MT significantly improved vascularized bone regeneration in a distal femur defect in rats. Micro-computed tomography analysis conducted 8 weeks post-surgery revealed that Scaffold@MT led to optimal development of new bone microarchitecture. Histological and immunohistochemical analyses demonstrated that Scaffold@MT facilitated bone matrix deposition and new blood vessel formation at the defect site. Overall, the utilization of melatonin-loaded nanofiber sponges exhibits significant promise as a scaffold that promotes bone growth and angiogenesis, making it a viable option for the repair of critical-sized bone defects.

Potassium release and mitigation by additives in different biomass combustion systems

Deposition formation on heat-exchanging surfaces and corrosion limit the use and efficiency of solid biomass combustion systems. The main influencing factors on these ash-related problems are the potassium content, the form in which the potassium is bound to the fuel matrix, and the temperature in the combustion system. To avoid these deposition problems, choosing the right fuel for a particular combustion system and vice versa is important.In this work, the temperature in fluidized bed, grate firing, and suspension combustion systems is analyzed by using the example of the power plants Altenstadt and Avedøre, as well as a European municipal solid waste incineration plant. Additionally, the temperature-resolved potassium release of ten different biofuels is analyzed in an electrothermal vaporization unit (ETV) connected to an inductively coupled plasma optical emission spectrometer (ICP-OES). The potential of additives to mitigate the potassium release is analyzed by adding kaolin and coal fly ash to miscanthus, torrefied wood, and beechwood.The results show that hardly any potassium is released into the gas phase at the typical temperatures of fluidized bed systems. Most of the potassium release occurs between 1000 °C and 1400 °C, the typical temperature range of grate combustion systems. This shows that reducing the temperature of the fuel on the grate could drastically reduce the potassium release. However, due to the negative effect on the efficiency, other measures, such as using additives for capturing potassium species, are favored. At the temperatures in suspension-fired combustion systems, almost all potassium is released into the gas phase, and additives cannot mitigate the release at these temperatures. Additives can shift the potassium release of miscanthus and torrefied wood while showing no positive effect when mixed with beechwood.All in all, this work enables a quantitative comparison of various biofuels and a rough evaluation of the suitability of a fuel regarding the deposition formation for different combustion systems.

Investigation of plasma chamber erosion in an RF ion source

Filament driven plasma sources are widely used to produce ion beams, but they require frequent maintenance due to the limited filament lifetime. External radio-frequency (RF) coupled ion source offers a filament-free plasma and hence better maintenance. However, one of the issues encountered during the development of a planar external RF-powered ion source at D-Pace was the erosion of its copper plasma chamber and subsequent formation of copper deposits on the Aluminum Nitride (AlN) RF window. The copper deposits on the RF window deteriorate the power coupling between the external antenna and the plasma. This paper investigates the erosion of the plasma chamber and describes some of the methods used to control the deposition of copper on the RF window.

Integrated treatment of wax and scale removal in old wells of the Tanjung Field

The majority of oil wells in the Tanjung Field are old wells with reservoir characterized by low pressure and temperature, as well as high water production. The characteristic of oil in the Tanjung Field has a relatively high wax content of 17.61%. This condition has led to several wells in the Tanjung Field experiencing issues with the simultaneous formation of wax and scale deposits within the wellbore equipment. The simultaneous occurrence of wax and scale can significantly impact the production rate. Therefore, addressing this production issue efficiently requires a method known as wax scale removal (WSR). WSR can effectively tackle the problem of wax and scale deposits occurring simultaneously in production equipment. In this method, a solvent for dissolving wax deposits and an acid for dissolving scale are injected together using the huff and puff technique.

Alzheimer's disease and herpes viruses: Current events and perspectives.

Alzheimer's disease (AD) is a real and current scientific and societal challenge. Alzheimer's disease is characterised by a neurodegenerative neuroinflammatory process, but the etiopathogenetic mechanisms are still unclear. The possible infectious aetiology and potential involvement of Herpes viruses as triggers for the formation of extracellular deposits of amyloid beta (Aβ) peptide (amyloid plaques) and intraneuronal aggregates of hyperphosphorylated and misfold could be a possible explanation. In fact, the possible genetic interference of Herpes viruses with the genome of the host neuronal cell or the stimulation of the infection to a continuous immune response with a consequent chronic inflammation could constitute those mechanisms underlying the development of AD, with possible implications in the understanding and management of the disease. Herpes viruses could be significantly involved in the pathogenesis of AD and in particular, their ability to reactivate in particular conditions such as immunocompromise and immunosenescence, could explain the neurological damage characteristic of AD. Our review aims to evaluate the state of the art of knowledge and perspectives regarding the potential relationship between Herpes viruses and AD, in order to be able to identify the possible etiopathogenetic mechanisms and the possible therapeutic implications.

Improvements in the Quantification of End-Member Vapor Compositions in Fluid Inclusion Boiling Assemblages and Implications for Metal Transport by Low-Density Fluids

Abstract Under conditions typically found in the Earth’s crust, there is a large pressure-temperature-composition range in the H2O-NaCl system where fluids may separate into a low-salinity vapor end member and a high-salinity liquid end member. However, heterogeneous trapping is common during the formation of fluid inclusions in an immiscible fluid system, violating the fundamental assumption of homogeneous entrapment for fluid inclusion microthermometry. This has profound consequences on the composition of these fluid phases and consequently on the formation of ore deposits from hydrothermal systems. At the same time, minor mixture of the high-salinity liquid phase with the low-salinity vapor phase cannot be distinguished from the end-member vapor-rich fluid inclusions by their bubble sizes. Precise determination of the salinities of vapor-rich fluid inclusions using microthermometry is deterred by the very small proportion of the liquid phase and the limitation of the analytical precision. All this will lead to erroneous compositional data from fluid inclusion analysis. We have quantitively calculated the variations of fluid inclusion properties caused by heterogeneous entrapment during phase separation in the H2O-NaCl system and showed that the salinity, and thereby the element contents and element/Na ratios of the vapor-rich fluid inclusions, is significantly changed in heterogeneously trapped fluid inclusions. The addition of 1 vol % of the high-salinity end member to the low-salinity end member results in a salinity change from 0.99 to 4.4 wt % NaCl equiv at the phase separation condition of 800 bar and 750°C. This will have a significant impact when it comes to determining the concentration of elements transported as chlorine complexes and typically leads to an overestimation of the mass transport capability by the vapor phase. Therefore, every effort should be taken during microthermometry to find and measure the least affected vapor-rich fluid inclusions. Our numerical calculations and synthetic fluid inclusions reveal that there is a linear relationship between the salinity and element contents for fluid inclusions at different extents of heterogeneous entrapment. Therefore, linear correction to the measured lowest vapor salinity can obtain a good approximation of the element contents in the end-member vapor phase.