Formation Of Deposits Research Articles

Coprecipitation of amorphous silica and gold nanoparticles contributes to gold hyperenrichment

Hyperenrichment of Au in orogenic ores occurs overwhelmingly within quartz veins, but the formation pathway of quartz veins in orogenic systems remains enigmatic. We conducted hydrothermal experiments simulating coprecipitation of Au and amorphous silica and subsequent recrystallization to test whether this is a viable mechanism to generate Au nuggets within quartz veins. Within minutes, coprecipitation of amorphous silica and Au nanoparticles occurred, representing an effective Au deposition mechanism. Within one week, amorphous silica had recrystallized to quartz, causing the coarsening of Au particles and their relocation to quartz grain boundaries and fractures. The experimental textures are similar to those observed in high-grade zones of orogenic gold deposits. In addition to trapping Au, amorphous silica may increase competency contrasts that facilitate short-term fracture reactivation during earthquake aftershock periods or swarms, allowing further Au input from fresh fluids. These findings demonstrate that amorphous silica precipitation may be an important transient stage in orogenic gold deposit formation, with significant implications for metal accumulation in quartz veins.

Possibility assessment for using protective coatings and polymer materials on tubing to prevent inorganic scaling on the inner surface of pipes

AbstractThe inorganic scaling in wells is a common problem faced by mining companies. At present, the use of protective coatings for tubing as a measure to prevent or reduce the formation of inorganic scale deposits on pipe walls has not been fully studied. To use protective coatings as a measure to counteract the deposition of inorganic salts, it is necessary to develop a method that allows assessing the ability of coatings, as well as polymer and metal materials, to prevent the formation of inorganic scale deposits on the inner surface of pipes.The article proposes a method for assessing the ability of protective coatings to resist the inorganic scaling on the inner surface of tubing. The proposed assessment method allows to make an informed decision on the advisability of using internal protective coatings of tubing to prevent (or reduce) the formation of inorganic scale deposits. The authors consider design features of a test bench for assessing the resistance of coatings to inorganic scale deposits, which allows to simulate the conditions for the formation of scale deposits that are as close as possible to the real conditions of oil production facilities. The article presents the results of bench tests of nine coating samples, two polymer samples and one sample made of St 40G2 steel. To assess the effectiveness of using tubing with an internal anti-corrosion coating as a measure to combat scale deposits, additional research is required to assess the possibility of complex use of coatings in conjunction with other methods of preventing processes of inorganic scaling. Thus, the authors developed the Bench for assessing the resistance of protective coatings of tubing to inorganic scale deposits. A dynamic testing technique is proposed to evaluate the resistance of protective coatings to inorganic scale deposits. Based on the presented results, conclusions were drawn about the possibility of using protective coatings on tubing as a measure to prevent the formation of inorganic scale deposits on the inner surface of the tubing.

Hotspot–subduction zone interactions and their resource effects at ∼120 Ma on the central Tibetan Plateau

The central Tibetan Plateau, particularly the Bangong–Nujiang suture zone, hosts abundant and complex Late Mesozoic geological records and world-class mineral resources. However, intense debate persists about the origin and tectonic setting of these geological records and mineral resources, which impedes a comprehensive understanding of regional Late Mesozoic tectonic evolution and mineralization. In this study, we investigated the petrochronology, geochemistry, and Sr-Nd-Hf isotopic characteristics of ∼120 Ma magmatic rocks in this region. We explored their petrogenesis and sources, and in conjunction with their spatiotemporal distribution and scale, we facilitated a first proposal that these magmatic rocks were derived from ∼120 Ma hotspot–subduction zone interaction and that world-class mineral deposits were formed in this geological setting. This study is the first to identify geological records of hotspot–subduction interaction in the central Tibetan Plateau and it has significant implications for gaining a deeper understanding of the closing processes of the Late Cretaceous Epoch in the Meso-Tethys Ocean. This study also highlights the substantial contribution of this hotspot–subduction zone interaction to the formation of world-class mineral deposits in the region, and thus has crucial significance for guiding mineral exploration in the central Tibetan Plateau.

Quartzites of the Khobeinskaya suite of the Subpolar Urals: Material composition, age limitations and possible sources of terrigenous material

Research subject. Quartzites that make up the ridge part of the ridge Rosomaha in the northern part of the Lyapinsky meganticlinorium in the Subpolar Urals. Material and methods. Detrital zircons were isolated from quartzites and their optical and isotope-geochronological U-Pb (LA-SF-ICP-MS) studies were performed. On the basis of chemical analyzes of rocks using indicator ratios and coefficients, the conditions for the formation of deposits were established. Results. The stratigraphic position of the quartzite ridge Rosomaha was determined. The time and conditions for the formation of the Khobeinskaya formation were specified. The role of polymetamorphic complexes of the Subpolar Urals as possible sources of terrigenous material removal during the formation of the Upper Precambrian section of the Subpolar Urals was estimated. Conclusions. It was established that the quartzites belong to the ridge Rosomaha to the Khobeinskaya formation, whose age is limited to the interval of 850–800 Ma (Inzersky level). It is shown that the crystalline complexes of Fennoscandia and the Central Russian orogen, as well as polymetamorphic complexes of the crystalline basement of the Timan-Severoural margin of the East European Platform, could be sources of terrigenous material.

Fluid inclusion and He-Ar-Pb isotope studies of the Dabie-type Leimengou giant porphyry Mo deposit, Qinling Orogen

The Leimengou deposit is a Dabie-type porphyry Mo system in the Leimengou-Qiyugou orefield of Qinling Orogen. Orebodies host within the porphyry and the metasedimentary Taihua Supergroup. However, the characteristics and sources of ore-forming fluid, metal precipitation mechanism, and the sources of mineralizing substances remain unclear. In this contribution, by a comprehensive study comprising an investigation of deposit geology, fluid inclusion microthermometry, and He-Ar-Pb isotope, we discuss the source and evolution of ore-forming fluids and the molybdenum precipitation mechanism of the Leimengou deposit. The mineralizing process is divided into the Stage I quartz ± K-feldspar vein in potassic altered zone, Stage IIa molybdenite ± quartz vein, and Stage IIb molybdenite + quartz + pyrite ± purple fluorite vein in silicification-phyllic altered zone, Stage III quartz + pyrite + sphalerite + galena ± chalcopyrite ± green fluorite ± pink calcite in prophylitic altered zone and Stage IV quartz ± calcite vein in carbonatization zone based on cross-relationship. The Stage IIa and IIb veins characterize the main molybdenum mineralization stages. By microthermometry, CO2-bearing (C-), Water (WV- and WL-), and daughter minerals-bearing (S-) types of inclusions were recognized. The Stage I quartz contains C-type fluid inclusion assemblages (FIAs) with a salinity of 6.3 ± 1.4 wt% NaCl equiv., and a total homogenization temperature (Th, total) of 473 ± 3 °C. This suggests that the early fluids show characteristics of high temperature, CO2-rich, and moderate salinity, distinguishing them from those of Endako-type and Climax-type deposits. C-type and coexisting W-type FIAs from Stage IIa show similar salinity, ranging from 1.9 to 13.0 wt% NaCl equiv. and 1.9 to 14.1 wt% NaCl equiv., with Th, total of 349–376 °C and 327–392 °C, respectively. Moreover, C-type FIAs homogenize to distinct phases and also show similar homogenization temperatures, indicating fluid immiscibility. The FIAs in Stage IIb show an average salinity of 8.3 ± 7.4 wt% NaCl equiv. and a Th, total of 302 ± 14 °C. WL-type and WV-type FIAs coexist, with similar temperatures varying from 308 to 310 °C during this stage, indicating significant fluid boiling. These observations indicate that the decrease in temperature, fluid immiscibility, and decompression boiling collectively led to the precipitation of molybdenite. Trapping pressures are estimated to be 82–231 MPa for Stage IIa and 43–115 MPa for Stage IIb, corresponding to ore-forming depths of approximately 8.4 km and 4.3 km, respectively. Additionally, the He-Ar isotopes obtained from pyrite indicate a clear mixing trend of crustal fluids with mantle fluids at Stage IIb, with mantle-derived fluid components increasing during Stage III. This coincides with the tectonic shift from regional compression to extension, leading to the formation of many Dabie-type Mo deposits, alongside crustal thinning and the upwelling of asthenospheric mantle materials. Futhermore, Pb isotopes from the ore, ore-hosted gneiss, and ore-causative granitoids demonstrate that the Taihua Supergroup gneiss supplied ore-forming materials, suggesting a crustal origin for the Leimengou Mo deposit.

Using compositions of zircon to reveal fertile magmas for the formation of porphyry deposits in the Loei and Truong Son fold belts, northern Laos

The Loei and Truong Son fold belts are well known as being the most geologically important and highly mineralized magmatic arc-related terranes in mainland southeast Asia. Numerous studies have examined the geology, geochemistry, and geochronology but only a few metallogenic and detailed deposit characterizations have been undertaken. This study of zircon geochemical analyses uses laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to provide U-Pb ages and magmatic fertility of felsic to intermediate volcanic and plutonic rocks from ten prospects in the Loei and Truong Son fold belts, in the northwest Laos region. The geochemical and geochronological analyses suggest at least three episodes of magmatism occurred: Silurian-Devonian (434–411 Ma), Early to Middle Permian (299–277 Ma), and Late Permian to Middle Triassic (253–243 Ma). The variable ranges of ɛHf values (−12 to + 12) suggest that mantle-derived and crustal contamination signatures are related to the history of subduction and arc magmatism in this region. Key trace elements and ratios associated with oxygen fugacity of magmas (e.g., Eu/Eu*, Dy/Yb, Ce/Nd, ΔFMQ) imply that the Phu Kham and the west of Vientiane along the Mekong River are likely to be fertile for porphyry copper deposits. In contrast, the Pha Gnai and other suites are less fertile. Using zircon as a fertility indication can be a valuable tool to distinguish between fertile and barren magmatic suites in this area.

Integrating soil geochemistry and machine learning for enhanced mineral exploration at the dayu gold deposit, south China block

Combining traditional geochemical methods with advanced analytical techniques is a hallmark of contemporary exploration efforts. This study explores the intricate geological dynamics of the Dayu gold deposit, located in the Dayao Uplift of the South China Block. Using a multidisciplinary approach that includes soil geochemistry, conventional geochemical methods and advanced computational techniques such as machine learning and Discriminant Projection Analysis (DPA), we aim to uncover the deposit formation information. Our results reveal a complex pattern of element anomalies, which serve as a geochemical fingerprint of the Au mineralization processes that shaped the deposit over geological time. Principal Component Analysis (PCA) and cluster analysis on soil samples highlight significant correlation among Au and its pathfinder elements. By leveraging the predictive capabilities of machine learning algorithms, particularly Convolutional Neural Networks (CNN), we improve exploration strategies, enhance the precision of target delineation and guide sampling efforts. DPA further identifies distinct discriminant functions, aiding in group differentiation and providing insights into prospective mineralization zones. This study exemplifies the integration of traditional and innovative methodologies, offering a pathway to a deeper understanding of mineralization processes and improving the effectiveness of exploration in complex geological terrains. The findings advance our knowledge of the Dayu gold deposit and demonstrate the potential of these integrated approaches in similar geological settings.

Evidence for polyimide redeposition and possible correlation with sparks in Gas Electron Multipliers working in CF[formula omitted] mixtures

Research on aging processes of Gas Electron Multipliers (GEMs) is important to obtain insights on how to increase the detector’s longevity, stability, and performance, as highlighted in the latest developments roadmap by the European Council of Future Accelerators (ECFA). One key aspect of the aging process is the deposit formation on the electrodes surfaces. In this work, through the analysis of the molecular content on the surface of a used GEM, we provide evidence for polyimide redeposition as a source of organic material contributing to the formation of insulating layers on the electrodes, which eventually lead to sparks and detector failure. Furthermore, we show that chromium, used to promote adhesion between copper and polyimide, in the device undergoes a diffusion process, effectively blurring the layered structure. We demonstrate the significance of surface-sensitive chemical analysis to investigate the surface deposits on electrodes of gaseous detectors and our results reveal the necessity of standardization and more stringent study protocols.

Hydrogeochemical characteristics and enrichment regularities of groundwater uranium in the Erlian basin, China

Groundwater is a key medium for the migration and enrichment of elements into ore bodies in sandstone-type uranium deposits, with anomalies of uranium elements and their associated components in water serving as indicators for exploring such deposits. The Erlian Basin, located in central-northern Inner Mongolia, is a crucial production area for sandstone-type uranium deposits in China. The groundwater flow system in the basin plays a significant role in the formation of uranium deposits. To study the hydrogeochemical characteristics and enrichment regularities of groundwater uranium in the Erlian Basin, 269 groundwater samples were collected. Hydrogeochemical analysis methods, such as Piper diagrams, Gibbs diagrams, and contour maps, were employed to determine the distribution characteristics and occurrence forms of groundwater uranium in the study area. The primary water chemistry types in the study area were HCO3–Ca•Na, HCO3–Na, HCO3•SO4–Na, and SO4•HCO3–Na•Ca. The distribution range of uranium content in groundwater in the study area was 0.1–453 μg/L (average of 53.08 μg/L). A comprehensive analysis, based on the direction of groundwater flow and changes in the redox environment, suggested that the higher uranium values in groundwater were distributed in the runoff and discharge areas, with uranium anomaly points existing in areas with alternating oxidation and reduction zones. These uranium anomaly points were in good agreement with the known large uranium deposits of Nuheting, Qiharigetu, Daoersu, and others, thereby predicting six other uranium hydrochemical anomaly points as prospective areas for uranium mineralization. The pH value distribution range in the study area's groundwater was 6.8–9.1, and the redox potential (Eh) value range was -126–52 mV, indicating that uranium exists in groundwater in the form of UO2(CO3)34− and UO2(CO3)22−. An increase in bicarbonate (HCO3−) is conducive to uranium dissolution. The enrichment and occurrence forms of uranium in groundwater are influenced by the concentrations of Fe and (Ca2++Mg2+), with uranium precipitation and enrichment occurring as the groundwater evolves and changes in the redox environment. The uranium content in deep wells is higher than in nearby shallow wells, indicating that deep water circulation is beneficial for mineralization. The pH, Eh, HCO3−, Fe, and other hydrogeochemical indicators are indicative of uranium enrichment; thus, they can be considered as reference bases when exploring for potential uranium resources.

SCALE INHIBITOR SQUEEZE TREATMENT: AN ADVANCED BIBLIOMETRIC ANALYSIS

The scale inhibitor squeeze treatment is an important method used in the petroleum industry to control formation of inorganic deposition within the oil production wells. This treatment increases the life cycle of petroleum production by preventing or reducing the formation and growth of salt crystals. In recent years, studies on inhibitor squeeze treatments have been expanding and diversifying with the goal of improving the lifespan and reducing treatment costs. This study reports an advanced bibliometric analysis from 1970 to 2023, illustrating the extent of research on inhibitor squeeze treatments to prevent the formation of inorganic scale, with a systematic survey since the first registered publication. It highlights the evolution of research reports, assessing the relationships between institutions, journals, and authors, identifying of potential needs to be addressed by future investigations.

Machine-learning oxybarometer developed using zircon trace-element chemistry and its applications

Abstract Magmatic oxygen fugacity (fO2) is a fundamental property to understanding the long-term evolution of the Earth’s atmosphere and the formation of magmatic-hydrothermal mineral deposits. Classically, the magmatic fO2 is estimated using mineral chemistry, such as Fe-Ti oxides, zircon, and hornblende. These methods, however, are only valid within certain limits and/or require a significant amount of a priori knowledge. In this contribution, a new oxybarometer, constructed by data-driven machine learning algorithms using trace elements in zircon and their corresponding independent fO2 constraints, is provided. Seven different algorithms are initially trained and then validated on a data set that was never utilized in the training processes. Results suggest that the oxybarometer constructed by the extremely randomized trees model has the best performance, with the largest R2 value (0.91 ± 0.01), smallest RMSE (0.45 ± 0.03), and low propagated analytical error (~0.10 log units). Feature importance analysis demonstrates that U, Ti, Th, Ce, and Eu in zircon are the key trace elements that preserve fO2 information. This newly developed oxybarometer has been applied in diverse systems, including arc magmas and mid-ocean ridge basalts, fertile and barren porphyry systems, and global S-type detrital zircon, which provide fO2 constraints that are consistent with other independent methods, suggesting that it has wide applicability. To improve accessibility, the oxybarometer was developed into a software application aimed at enabling more consistent and reliable fO2 determinations in magmatic systems, promoting further research.

APPROACH TO MATHEMATICAL MODELING OF THE COST OF APPLYING COATINGS TO PREVENT THE FORMATION OF ARPD

The authors explore the topic of operation of main oil pipelines, complicated by the formation and settling of asphalt, resin, and paraffin deposits (wax deposits). It is known that the fallout of paraffin deteriorates the technological characteristics of the pipeline, which has a number of negative consequences from an economic point of view: a decrease in income due to a narrowing of the flow area and the volume of pumped oil, an increase in costs due to the increased load on main pumps. Today, there are many different ways to combat wax deposits, primarily aimed at preventing the fallout or removing formed deposits from the internal surface of an oil pipeline, the effectiveness of which is determined individually for each pipeline due to the complexity in assessing the influence of the rheological characteristics of oil and the geological conditions of the pipeline on the effectiveness of the methods. One of the additional and universal options for combating wax deposits is the use of internal and external protective coatings.The authors have developed a number of models of oil pipelines that use oils from various oil and gas basins, differing in paraffin content, and considering the presence of insulation of various protective coatings (paint and varnish, highly reinforced protective coating (VUS), bitumen-mastic VUS, polyurethane foam) and their combinations. For these models, the Schlumberger OLGA program simulated the operation of the pipeline for 180 days, on the basis of which the maximum thickness of the formed paraffin was estimated, and the specific energy costs for pumping through the pipeline without coating and various types of coating were calculated, after which the calculation was performed main economic indicators of pipeline operation for each option. Based on the calculation results, it was concluded that it is advisable to use one or another coating based on the shortest payback period. This comprehensive assessment demonstrates a methodology for assessing the effectiveness of the use of protective coatings from both a technological and economic point of view and allows us to draw conclusions about the possibility of using one or another option based on the results of the study, depending on the composition of the oil.

Synthesis of La1-xSrxCoO3-δ and its catalytic oxidation of NO and its reaction path

The oxidation rate of NO to NO2 is a critical parameter in the removal of NOx within selective catalytic reduction (SCR) systems. LaCoO3-δ is a kind of potential catalyst to enhance the oxidation of NO to NO2, it may offers an economic and stable alternative to noble metal catalysts, particularly at elevated temperatures. This study aimed to enhance the catalytic efficiency of LaCoO3-δ through strontium (Sr) doping. La1-xSrxCoO3-δ (with varying x values of 0.1, 0.2, 0.3, 0.4) was synthesized using a sol-gel method. La1-xSrxCoO3-δ exhibited superior NO oxidation catalytic activity compared to LaCoO3-δ, with the most notable enhancement observed at x = 0.3 (84 % conversion). This improvement can be attributed to the substitution of La3+ with Sr2+, which induces lattice distortion and charge imbalance, thereby creating more oxygen vacancies that enhance the catalytic oxidation capability of La1-xSrxCoO3-δ. However, it's important to note that an excessive amount of Sr can result in the formation of SrCO3 deposits on the surface of La1-xSrxCoO3-δ, thereby diminishing its catalytic oxidation performance. The catalytic oxidation reaction behavior adhered most closely to the O2-adsorbed E-R model, the surface defects in La1-xSrxCoO3-δ playing a pivotal role in the catalytic reaction.

Unlocking New Approaches to Urolithiasis Management Via Nutraceuticals.

Urolithiasis, commonly known as kidney stones, is characterized by the formation of hard deposits in the urinary tract. These stones can cause severe pain and discomfort, and their management typically involves a combination of medical interventions and lifestyle modifications. According to the literature, 30% and 50% of urolithiasis cases recur. Between 9 and 12% of persons in industrialised countries are predicted to have urolithiasis at some time. Due to the high frequency of stone formation, recurrent nature, and prevalence in adults, it has a significant impact on society, the person, and the health care system. Adopting the best prophylactic measures is crucial in light of these developments to decrease the impact of urolithiasis on individuals and society. In recent years, there has been growing interest in the potential role of nutraceuticals in the management of urolithiasis. Nutraceuticals, such as herbal extracts, vitamins, minerals, and probiotics, have gained recognition for their potential in promoting urinary health and reducing the risk of urolithiasis. These compounds can aid in various ways, including inhibiting crystal formation, enhancing urine pH balance, reducing urinary calcium excretion, and supporting kidney function. Additionally, nutraceuticals can help alleviate symptoms associated with urolithiasis, such as pain and inflammation. While medical interventions remain crucial, incorporating nutraceuticals into a comprehensive management plan can offer a holistic approach to urolithiasis, improving patient outcomes and quality of life. Therefore, nutraceuticals may be a desirable choice for treating and avoiding recurring urolithiasis for patients and medical professionals. Therefore, the present study has focused on nutraceuticals' role in preventing urolithiasis.

Dual-layered carbonated hydroxyapatite/polypyrrole: A novel strategy for bone fracture repair implants

This study presents the fabrication of a carbonate-doped hydroxyapatite/polypyrrole thin film on 304 stainless steel (CHA/PPY/304 SS) using a cyclic voltammetry electrochemical method to enhance bone fracture repair. The in-situ substitution mechanism was evaluated through estimated reaction energy, and the impact of surface modification on structural properties was examined using the Rietveld refinement method. Following the electrodeposition of CHA on PPY-coated 304 SS, a distinctive flower-like structure emerged, with average cluster and pore sizes of 3 ± 1 μm and 130 ± 10 nm, respectively. Rietveld refinement analysis revealed A-type carbonate substitution, indicated by an increase in the a parameter and a reduction in the c parameter compared to the standard. Subsequent deposition of the bilayer coating on 304 SS significantly improved adhesion strength to 10.7 ± 0.2 MPa, along with increased hydrophilicity and Vickers hardness. Notably, enhanced bioactivity was observed, evidenced by thickened nanoflake-like structures and the formation of island-like apatite deposits after immersion in simulated body fluid (SBF) for 7 days. This bilayer coating shows promise for surface modification of metallic implants and tissue engineering scaffolds.

Timing of Volatile Degassing From Hydrous Upper‐Crustal Magma Reservoirs With Implications for Porphyry Copper Deposits

AbstractThe timing and duration of volatile generation from crystallizing magma reservoirs and fluid release across the magmatic‐hydrothermal interface depend on complex coupled interactions controlled by non‐linear, dynamic properties of magmas, rocks and fluids. Understanding these mechanisms is essential to explain the rare formation of economic porphyry copper deposits. For this study, we further developed a coupled numerical model that can simultaneously resolve magma and hydrothermal flow by introducing a description of fluid transport within the magma reservoir and volatile release to the host rock. Our simulations use realistic magma properties derived from published experimental and modeling studies and cover different magma compositions and water contents. We show that magma convection at melt‐dominated states leads to homogenization, which delays fluid release and promotes a rapid evolution toward a mush state. The onset of magmatic volatile release can be near‐explosive with a tube‐flow outburst event lasting <100 years for high initial water contents of >3.5 wt% H2O that could result in the formation of hydrothermal breccias and vein stockworks or trigger eruptions. This event can be followed by sustained fluid release at moderate rates by volatile flushing caused by magma convection. Subsequent fluid release from concentric tube rings by radial cooling of non‐convecting magma mush with a volume of ∼100 km3 at ∼5 km depth is limited to remaining water contents of ∼3.1 wt% H2O and lasts 50–100 kyr. Ore formation from hydrous magmas may thus involve distinct phases of volatile release.

GLP-1/GIP Agonist as an Intriguing and Ultimate Remedy for Combating Alzheimer's Disease through its Supporting DPP4 Inhibitors: A Review.

Alzheimer's disease (AD) is a widespread neurological illness in the elderly, which impacted about 50 million people globally in 2020. Type 2 diabetes has been identified as a risk factor. Insulin and incretins are substances that have various impacts on neurodegenerative processes. Preclinical research has shown that GLP-1 receptor agonists decrease neuroinflammation, tau phosphorylation, amyloid deposition, synaptic function, and memory formation. Phase 2 and 3 studies are now occurring in Alzheimer's disease populations. In this article, we present a detailed assessment of the therapeutic potential of GLP-1 analogues and DPP4 inhibitors in Alzheimer's disease. This study aimed to gain insight into how GLP-1 analogues and associated antagonists of DPP4 safeguard against AD. This study uses terms from search engines, such as Scopus, PubMed, and Google Scholar, to explore the role, function, and treatment options of the GLP-1 analogue for AD. The review suggested that GLP-1 analogues may be useful for treating AD because they have been linked to anti-inflammatory, neurotrophic, and neuroprotective characteristics. Throughout this review, we discuss the underlying causes of AD and how GLP signaling functions. With a focus on AD, the molecular and pharmacological effects of a few GLP-1/GIP analogs, both synthetic and natural, as well as DPP4 inhibitors, have been mentioned, which are in the preclinical and clinical studies. This has been demonstrated to improve cognitive function in Alzheimer's patients.

Comparative analysis of the effectiveness of inhibitors preventing the formation of high molecular hydrocarbon deposits

Comparative analysis of the effectiveness of inhibitors preventing the formation of high molecular hydrocarbon deposits

Investigation on formation and combustion process of carbon deposits from coke oven riser during waste heat recovery

In the context of carbon neutrality, the widespread application of waste heat recovery systems in steel production is crucial for energy conservation and emission reduction. This study investigates the formation and combustion removal mechanisms of carbon deposits in coke oven risers during waste heat recovery by analyzing the physicochemical structure, combustion behavior, and kinetics of different layers. The results revealed that lower temperatures near the tube wall produced higher volatile content in the lower layer. Over time, the carbon deposits gradually graphitized from bottom to top. Under long-term heating and iron catalysis, the lower carbon deposits showed a higher order degree and poorer combustion performance. The middle layer, characterized by more pores formed during polycondensation, exhibited a larger specific surface area than other samples and burned slightly faster than the upper layer. Increasing heating and airflow rates could linearly enhance the combustion efficiency of carbon deposits. The random pore model accurately described the combustion process of the upper and middle layers, whereas the multi-stage weight loss in lower deposits aligned better with a multi-stage reaction random pore model. This research could further strengthen the understanding of carbon deposits in the riser and improve the removal effect, thereby promoting waste heat recovery from coke oven gas.

The formation of carbon deposits on catalyst during sulfurization of iron-oxides with aromatics as liquid medium

To obtain the proper catalyst activity for direct coal liquefaction, the iron-oxides, as a precursor of iron-based catalysts, were sulfurized in the liquid medium before use. The hydrogen-donating solvent, a promising liquid medium, benefited the process design. However, it was found to be not conducive to the catalyst activity. Herein, the influence on catalysts from aromatics was investigated. Synthetic iron-oxides were sulfurized under H2S flow in the mixtures of decalin and selected aromatics including xylene, naphthalene, phenanthrene and pyrene. The catalyst activity was evaluated based on its performance in the catalytic hydrogenation of naphthalene. It was found that pyrene had a significant negative effect on catalyst activity, which was mainly related to the condensation of pyrene on the catalyst. The fact was that the amount and condensation degree of carbon deposits on the tested catalysts were inversely proportional to their activities. The condensation of pyrene was related to both elemental sulfur and iron species. The effect from the two factors separately on pyrene condensation was limited, while the synergetic effect when they worked together made the condensation extent increased significantly. The elemental sulfur reacted with pyrene at elevated temperatures and induced the condensation of pyrene. Besides, density-functional-theory calculation results revealed that the chemical bonds of both elemental sulfur and pyrene were weakened by iron-sulfides.