Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (51)

Search Parameters:
Keywords = bi-fluid combination

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
23 pages, 12729 KB  
Article
Genetic Mineralogical Characteristics of Pyrite and Quartz from the Qiubudong Silver Deposit, Central North China Craton: Implications for Ore Genesis and Exploration
by Wenyan Sun, Jianling Xue, Zhiqiang Tong, Xueyi Zhang, Jun Wang, Shengrong Li and Min Wang
Minerals 2025, 15(8), 769; https://doi.org/10.3390/min15080769 - 22 Jul 2025
Viewed by 477
Abstract
The Qiubudong silver deposit on the western margin of the Fuping ore cluster in the central North China Craton is a representative breccia-type deposit characterized by relatively high-grade ores, thick mineralized zones, and extensive alteration, indicating considerable potential for economic resource development and [...] Read more.
The Qiubudong silver deposit on the western margin of the Fuping ore cluster in the central North China Craton is a representative breccia-type deposit characterized by relatively high-grade ores, thick mineralized zones, and extensive alteration, indicating considerable potential for economic resource development and further exploration. Previous studies on this deposit have not addressed its genetic mineralogical characteristics. This study focuses on pyrite and quartz to investigate their typomorphic features, such as crystal morphology, trace element composition, thermoelectric properties, and luminescence characteristics, and their implications for ore-forming processes. Pyrite crystals are predominantly cubic in early stages, while pentagonal dodecahedral and cubic–dodecahedral combinations peak during the main mineralization stage. The pyrite is sulfur-deficient and iron-rich, enriched in Au, and relatively high in Ag, Cu, Pb, and Bi contents during the main ore-forming stage. Rare earth element (REE) concentrations are low, with weak LREE-HREE fractionation and a strong negative Eu anomaly. The thermoelectric coefficient of pyrite ranges from −328.9 to +335.6 μV/°C, with a mean of +197.63 μV/°C; P-type conduction dominates, with an occurrence rate of 58%–100% and an average of 88.78%. A weak–low temperature and a strong–high temperature peak characterize quartz thermoluminescence during the main mineralization stage. Fluid inclusions in quartz include liquid-rich, vapor-rich, and two-phase types, with salinities ranging from 10.11% to 12.62% NaCl equiv. (average 11.16%) and densities from 0.91 to 0.95 g/cm3 (average 0.90 g/cm3). The ore-forming fluids are interpreted as F-rich, low-salinity, low-density hydrothermal fluids of volcanic origin at medium–low temperatures. The abundance of pentagonal dodecahedral pyrite, low Co/Ni ratios, high Cu contents, and complex quartz thermoluminescence signatures are key mineralogical indicators for deep prospecting. Combined with thermoelectric data and morphological analysis, the depth interval around 800 m between drill holes ZK3204 and ZK3201 has high mineralization potential. This study fills a research gap on the genetic mineralogy of the Qiubudong deposit and provides a scientific basis for deep exploration. Full article
(This article belongs to the Special Issue Using Mineral Chemistry to Characterize Ore-Forming Processes)
Show Figures

Figure 1

15 pages, 5137 KB  
Article
Research on Fault Diagnosis of Vertical Centrifugal Pump Based on Multi-Channel Information Fusion
by Yifan Zhi, Qian Huang, Fudong Tao, Huairui Li, Da Hao, Haoyang Qin and Qiang Fu
Processes 2025, 13(4), 1152; https://doi.org/10.3390/pr13041152 - 10 Apr 2025
Viewed by 646
Abstract
Aiming at the mechanical failures of vertical centrifugal pumps generated under the combined effects of centrifugal force and fluid power, which are difficult to be accurately recognized by traditional diagnostic methods, a vertical centrifugal pump fault diagnosis method based on the combination of [...] Read more.
Aiming at the mechanical failures of vertical centrifugal pumps generated under the combined effects of centrifugal force and fluid power, which are difficult to be accurately recognized by traditional diagnostic methods, a vertical centrifugal pump fault diagnosis method based on the combination of convolutional neural network (CNN) and bidirectional long and short-term memory neural network (BiLSTM) is proposed. Firstly, a recurrent neural network is introduced on the basis of a convolutional neural network, and a feature extraction and fault classification module is established, which can automatically extract spatial and temporal features from the original input signals and identify the key fault modes. Subsequently, a vertical centrifugal pump fault simulation test rig is built, and the vibration signals of the centrifugal pumps under different faults are collected and used to train the proposed diagnostic model. Finally, the diagnostic models constructed by CNN and BiLSTM are compared with a single CNN diagnostic model for fault identification of vibration signals under different fault conditions. The results of the study show that the accuracy of fault diagnosis reaches 100% by using the technique of multi-channel information fusion, which verifies the advantages of multi-channel data fusion. Moreover, the addition of BiLSTM on the basis of CNN is able to better extract and capture useful information from the time series data. In summary, the method proposed in this study can effectively improve the fault diagnosis accuracy and reliability of vertical centrifugal pumps, providing a feasible technical solution for equipment health monitoring in engineering practice. Full article
(This article belongs to the Section Process Control and Monitoring)
Show Figures

Figure 1

15 pages, 3462 KB  
Article
Ionic Liquid Electrolyte Technologies for High-Temperature Lithium Battery Systems
by Eleonora De Santis, Annalisa Aurora, Sara Bergamasco, Antonio Rinaldi, Rodolfo Araneo and Giovanni Battista Appetecchi
Int. J. Mol. Sci. 2025, 26(7), 3430; https://doi.org/10.3390/ijms26073430 - 6 Apr 2025
Cited by 2 | Viewed by 1864
Abstract
The advent of the lithium-ion batteries (LIBs) has transformed the energy storage field, leading to significant advances in electronics and electric vehicles, which continuously demand more and more performant devices. However, commercial LIB systems are still far from satisfying applications operating in arduous [...] Read more.
The advent of the lithium-ion batteries (LIBs) has transformed the energy storage field, leading to significant advances in electronics and electric vehicles, which continuously demand more and more performant devices. However, commercial LIB systems are still far from satisfying applications operating in arduous conditions, such as temperatures exceeding 100 °C. For instance, safety issues, materials degradation, and toxic stem development, related to volatile, flammable organic electrolytes, and thermally unstable salts (LiPF6), limit the operative temperature of conventional lithium-ion batteries, which only occasionally can exceed 50–60 °C. To overcome this highly challenging drawback, the present study proposes advanced electrolyte technologies based on innovative, safer fluids such as ionic liquids (ILs). Among the IL families, we have selected ionic liquids based on tetrabutylphosphonium and 1-ethyl-3-methyl-imidazolium cations, coupled with per(fluoroalkylsulfonyl)imide anions, for standing out because of their remarkable thermal robustness. The thermal behaviour as well as the ion transport properties and electrochemical stability were investigated even in the presence of the lithium bis(trifluoromethylsulfonyl)imide salt. Conductivity measurements revealed very interesting ion transport properties already at 50 °C, with ion conduction values ranging from 10−3 and 10−2 S cm−1 levelled at 100 °C. Thermal robustness exceeding 150 °C was detected, in combination with anodic stability above 4.5 V at 100 °C. Preliminary cycling tests run on Li/LiFePO4 cells at 100 °C revealed promising performance, i.e., more than 94% of the theoretical capacity was delivered at a current rate of 0.5C. The obtained results make these innovative electrolyte formulations very promising candidates for high-temperature LIB applications and advanced energy storage systems. Full article
Show Figures

Figure 1

22 pages, 29178 KB  
Article
Molybdenite Re–Os and Zircon U–Pb Isotopic Constraints on Gold Mineralization Associated with Fine-Grained Granite in the Xiawolong Deposit, Jiaodong Peninsula, East China
by Mingchao Wu, Zhongliang Wang and Pengyu Liu
Appl. Sci. 2025, 15(3), 1199; https://doi.org/10.3390/app15031199 - 24 Jan 2025
Viewed by 817
Abstract
Molybdenite Re–Os and zircon U–Pb isotopic data are first obtained from the stockwork and disseminated-style gold-bearing ores and the fine-grained granite hosting these ores in the Xiawolong gold mine, respectively, which is located within the Muping–Rushan gold metallogenic belt, eastern Jiaodong Peninsula, so [...] Read more.
Molybdenite Re–Os and zircon U–Pb isotopic data are first obtained from the stockwork and disseminated-style gold-bearing ores and the fine-grained granite hosting these ores in the Xiawolong gold mine, respectively, which is located within the Muping–Rushan gold metallogenic belt, eastern Jiaodong Peninsula, so as to illustrate the genesis of gold mineralization and its implication for exploration. Four molybdenite samples yield a well-defined Re–Os isochron age of 118.4 ± 2.5 Ma (2σ), which is identical to the weighted average Re–Os model age of 118 ± 1.7 Ma (2σ). Integration of the new geochronologic data with those reported recently from the other gold mines in the Muping–Rushan gold metallogenic belt suggests that a discrete gold event occurred in Xiawolong ca. 4 m.y. older than that for the other gold mineralization at ca. 114 Ma in eastern Jiaodong. In addition, two fine-grained granite samples, measured using the LA-ICP-MS zircon U–Pb method, produce the first precise ages of 118 ± 2 to 117 ± 2 Ma (2σ), identical to the molybdenite Re–Os ages, within the margin of error and obtained in this study. The fine-grained granite has a similar lithology and emplacement age as those of the medium-grained monzogranite consisting of the marginal facies of the Sanfoshan batholith, and is considered to be the crystallization products of Sanfoshan granitic magma in the late stage. Combined with the previous S-Pb-D-O isotope, fluid inclusion and geological studies, which suggest that the ore-forming fluid of Xiawolong gold mineralization is from magmatic water, and the identification that the magnetite coexists with the gold-bearing pyrite and molybdenite in the gold ores, which indicates a high oxygen fugacity (fO2) of both the magma and resultant hydrothermal fluids, it is logical to infer that the Xiawolong gold deposit is genetically in relation to the Sanfoshan granitic magmatism, which is high in fO2 and rich in Au at the magmatic–hydrothermal transition stage, and the change in fO2 mostly likely makes a significant contribution to the precipitation of Au. This result reveals that the late-stage granitic magma with high fO2, which is crystallized into the fine-grained granite, probably is also rich in Au, except the W–Mo–Cu–Zn–U–Be–Li–Nb–Ta–Sn–Bi-elements. Therefore, based on the extensional tectonic regime for the early Cretaceous Jiaodong gold deposits, we propose that gold exploration in the Jiaodong should not only focus on the fault-hosted Au but also on the fine-grained granite-hosted Au around the apical portions of the late Early Cretaceous small-granitic intrusions with high fO2. This model could also be important for prospecting in other gold ore districts, which have a similar tectonic setting. Full article
(This article belongs to the Special Issue Technologies and Methods for Exploitation of Geological Resources)
Show Figures

Figure 1

22 pages, 4121 KB  
Article
Geochemistry and Fluid Inclusion of Epithermal Gold-Silver Deposits in Kamchatka, Russia
by Maria Shapovalova, Elena Shaparenko and Nadezhda Tolstykh
Minerals 2025, 15(1), 2; https://doi.org/10.3390/min15010002 - 24 Dec 2024
Cited by 3 | Viewed by 1861
Abstract
The work focuses on five epithermal Au-Ag deposits of the Kamchatka volcanogenic belts: Rodnikovoe, Baranyevskoe, Kumroch, Lazurnoe (adularia-sericite type–Ad-Ser) and Maletoyvayam (acid-sulfate type–Ac-Sul). The geochemical characteristics of the deposits were presented based on the results of ICP-OES and fire-assay analysis. The compositions and [...] Read more.
The work focuses on five epithermal Au-Ag deposits of the Kamchatka volcanogenic belts: Rodnikovoe, Baranyevskoe, Kumroch, Lazurnoe (adularia-sericite type–Ad-Ser) and Maletoyvayam (acid-sulfate type–Ac-Sul). The geochemical characteristics of the deposits were presented based on the results of ICP-OES and fire-assay analysis. The compositions and physicochemical parameters of ore-forming fluids were based on microthermometry, Raman spectroscopy and gas chromatography-mass spectrometry. It was shown that all deposits were comparable in terms of temperatures, salinity and the predominance of H2O and CO2 in ore-forming fluids. The deposits were formed at temperatures of 160–308 °C by aqueous fluids with salinities of 0.5–6.8 wt. % (NaCl-eq.). The Maletoyvayam deposit differed from the other ones in significant enrichment in Se, Te, Sb, Bi and As, as well as much higher concentrations of hydrocarbons, nitrogenated and sulfonated compounds (31.4 rel.% in total) in the composition of fluid inclusions. This gave us a reason to assume that organic compounds favourably affected the concentrations of these elements in the mineralising fluid. Kumroch and Lazurnoe were distinguished from Rodnikovoe and Baranyevskoe by high Zn, Pb and Cu contents, where each of them represented a single system combining both Ad-Ser type epithermal gold-silver and copper porphyry mineralisations. The presence of alkanes, esters, ketones, carboxylic acids and aldehydes in different quantities at all deposits were indicators of the combination of biogenic and thermogenic origins of organic compounds. The contents of ore-forming elements in ores were consistent with the specificity of mineral assemblages in the Kamchatka deposits. Full article
Show Figures

Figure 1

23 pages, 4202 KB  
Article
Performance Analysis and Optimization of a Channeled Photovoltaic Thermal System with Fin Absorbers and Combined Bi-Fluid Cooling
by Hamza Nasri, Jamel Riahi, Hatem Oueslati, Hichem Taghouti and Silvano Vergura
Computation 2024, 12(9), 188; https://doi.org/10.3390/computation12090188 - 15 Sep 2024
Cited by 2 | Viewed by 1435
Abstract
The conversion efficiency of photovoltaic (PV) cells can be increased by reducing high temperatures with appropriate cooling. Passive cooling systems using air, water, ethylene glycol, and air/water+TiO2 nano bi-fluid froth in the duct channel have been studied, but an overall assessment is [...] Read more.
The conversion efficiency of photovoltaic (PV) cells can be increased by reducing high temperatures with appropriate cooling. Passive cooling systems using air, water, ethylene glycol, and air/water+TiO2 nano bi-fluid froth in the duct channel have been studied, but an overall assessment is essential for its possible application. In the present work, a numerical study is adopted to investigate the impact of the fluid-duct channel type on the electrical and thermal efficiency of the photovoltaic thermal (PVT) collector. Such investigation is achieved by means of a MATLAB R2022b code based on the Runge–Kutta (RK4) method. Four kinds of fluid duct channels are used to optimize the best fluid for improving the overall efficiency of the investigated PVT system. The numerical validation of the proposed model has been made by comparing the numerical and experimental results reported in the literature. The outcomes indicate that varying the duct channel nature affects mainly the electrical and thermal efficiency of the PVT collector. Our results validate that the nature of the fluid affects weakly the electrical efficiency, whereas the thermal efficiency is strongly affected. Accordingly, it is observed that PVT collectors based on nano bi-fluid air/water+TiO2 give the best performance. In this context, an appreciable increase in the overall efficiency of 22% is observed when the water+TiO2 fluid is substituted by air/ water+TiO2 nano bi-fluid. Therefore, these motivating results make the PVT nano bi-fluid efficient and suitable for solar photovoltaic thermal applications since this system exhibits a daily overall efficiency of about 56.96%. The present work proves that controlling the design, cooling technique, and nature of the cooling fluid used is a crucial factor for improving the electrical, thermal, and overall efficiency of the PVT systems. Full article
(This article belongs to the Section Computational Engineering)
Show Figures

Graphical abstract

32 pages, 85969 KB  
Article
Platinum Group Minerals Associated with Nickel-Bearing Sulfides from the Jatobá Iron Oxide-Copper-Gold Deposit, Carajás Domain, Brazil
by Yuri Tatiana Campo Rodriguez, Nigel J. Cook, Cristiana L. Ciobanu, Maria Emilia Schutesky, Samuel A. King, Sarah Gilbert and Kathy Ehrig
Minerals 2024, 14(8), 757; https://doi.org/10.3390/min14080757 - 26 Jul 2024
Cited by 4 | Viewed by 2439
Abstract
An enrichment in nickel (Ni) or platinum group elements (PGE) is seldom observed in ores of the iron oxide–copper–gold (IOCG) type. This phenomenon is, however, known from a few deposits and prospects in the Carajás Mineral Province, Brazil. The Ni-PGE enrichment is explained, [...] Read more.
An enrichment in nickel (Ni) or platinum group elements (PGE) is seldom observed in ores of the iron oxide–copper–gold (IOCG) type. This phenomenon is, however, known from a few deposits and prospects in the Carajás Mineral Province, Brazil. The Ni-PGE enrichment is explained, in part, by the spatial association of the IOCG-type ores with altered mafic-ultramafic lithologies, as well as by reworking and remobilization of pre-existing Ni and PGE during multiple mineralization and tectonothermal events across the Archean-Proterozoic. One such example of this mineralization is the Jatobá deposit in the southern copper belt of the Carajás Domain. This is the first detailed study of the Ni and PGE mineralization at Jatobá, with implications for understanding ore genesis. Petrographic and compositional study of sulfides shows that pyrite is the main Ni carrier, followed by pyrrhotite and exsolved pentlandite. Measurable concentrations of palladium (Pd) and platinum (Pt), albeit never more than a few ppm, are noted in pyrite. More importantly, however, the trace mineral signature of the Jatobá deposit features several platinum group minerals (PGM), including merenskyite, naldrettite, sudburyite, kotulskite, sperrylite, and borovskite. These PGM occur as sub-10 µm-sized grains that are largely restricted to fractures and grain boundaries in pyrite. All Pd minerals reported contain mobile elements such as Te, Bi, and Sb and are associated with rare earth- and U-minerals. This conspicuous mineralogy, differences in sulfide chemistry between the magnetite-hosted ore and stringer mineralization without magnetite, and microstructural control point to a genetic model for the sulfide mineralization at Jatobá and its relative enrichment in Ni and PGE. Observations support two alternative scenarios for ore genesis. In the first, an initial precipitation of disseminated or semi-massive Ni-PGE-bearing sulfides took place within the mafic rock pile, possibly in a VHMS-like setting. Later partial dissolution and remobilization of this pre-existing mineralization by mineralizing fluids of IOCG-type, possibly during the retrograde stage of a syn-deformational metamorphic event, led to their re-concentration within magnetite along structural conduits. The superposition of IOCG-style mineralization onto a pre-existing assemblage resulted in the observed replacement and overprinting in which PGE combined with components of the IOCG fluids like Sb, Bi, and Te. An alternative model involves leaching, by the IOCG-type fluids, of Ni and PGE from komatiites within the sequence or from ultramafic rocks in the basement. The discovery of PGM in Jatobá emphasizes the potential for additional discoveries of Ni-PGE-enriched ores elsewhere in the Carajás Domain and in analogous settings elsewhere. Full article
Show Figures

Figure 1

15 pages, 6723 KB  
Article
Localised Objective Characterisation Assessment of Lymphoedema (LOCAL): Using High-Frequency Ultrasound, Bioelectrical Impedance Spectroscopy and Volume to Evaluate Superficial Tissue Composition
by Jennifer Sanderson, Neil Tuttle, Robyn Box, Hildegard Reul-Hirche and E-Liisa Laakso
Diagnostics 2024, 14(15), 1616; https://doi.org/10.3390/diagnostics14151616 - 26 Jul 2024
Cited by 2 | Viewed by 1561
Abstract
Lymphoedema tissue is characterised by excess free fluid and structural changes to the extracellular matrix (ECM) in the form of fibrotic and fatty deposition. These tissue characteristics are integral to the assessment of lymphoedema progression; however, clinicians and researchers often focus on changes [...] Read more.
Lymphoedema tissue is characterised by excess free fluid and structural changes to the extracellular matrix (ECM) in the form of fibrotic and fatty deposition. These tissue characteristics are integral to the assessment of lymphoedema progression; however, clinicians and researchers often focus on changes in the free fluid, volume and function of lymphatic vasculature to inform practice. Subsequently, little is known about the effect of clinical interventions on lymphoedema tissue composition. This article presents a novel approach to classify lymphoedema tissue. The Localised Objective Characterisation Assessment of Lymphoedema (LOCAL) classification combines diagnostic and clinically meaningful objective assessment thresholds to infer lymphoedema pathophysiological changes in tissue layers. The LOCAL classification method was verified using data from fifteen women with unilateral breast cancer-related lymphoedema who were evaluated at three sites on each arm using high-frequency ultrasound (HFUS), bio-electrical impedance spectroscopy (BIS) and volume measurements. Participants exhibited an uneven distribution of volume between the proximal and distal segments of the arm (p = 0.023), with multiple tissue compositional categories observed across sites on the same limb (p < 0.001). The LOCAL method demonstrated utility in categorising a diverse range of lymphoedema tissue layer changes beyond what can be ascertained from whole-limb measures. Full article
(This article belongs to the Special Issue Ultrasound in the Diagnosis and Management of Skin Diseases)
Show Figures

Figure 1

13 pages, 3201 KB  
Article
Dual Semi-Interpenetrating Networks of Water-Soluble Macromolecules and Supramolecular Polymer-like Chains: The Role of Component Interactions
by Anna L. Makarova, Alexander L. Kwiatkowski, Alexander I. Kuklin, Yuri M. Chesnokov, Olga E. Philippova and Andrey V. Shibaev
Polymers 2024, 16(10), 1430; https://doi.org/10.3390/polym16101430 - 17 May 2024
Viewed by 1574
Abstract
Dual networks formed by entangled polymer chains and wormlike surfactant micelles have attracted increasing interest in their application as thickeners in various fields since they combine the advantages of both polymer- and surfactant-based fluids. In particular, such polymer-surfactant mixtures are of great interest [...] Read more.
Dual networks formed by entangled polymer chains and wormlike surfactant micelles have attracted increasing interest in their application as thickeners in various fields since they combine the advantages of both polymer- and surfactant-based fluids. In particular, such polymer-surfactant mixtures are of great interest as novel hydraulic fracturing fluids with enhanced properties. In this study, we demonstrated the effect of the chemical composition of an uncharged polymer poly(vinyl alcohol) (PVA) and pH on the rheological properties and structure of its mixtures with a cationic surfactant erucyl bis(hydroxyethyl)methylammonium chloride already exploited in fracturing operations. Using a combination of several complementary techniques (rheometry, cryo-transmission electron microscopy, small-angle neutron scattering, and nuclear magnetic resonance spectroscopy), we showed that a small number of residual acetate groups (2–12.7 mol%) in PVA could significantly reduce the viscosity of the mixed system. This result was attributed to the incorporation of acetate groups in the corona of the micellar aggregates, decreasing the molecular packing parameter and thereby inducing the shortening of worm-like micelles. When these groups are removed by hydrolysis at a pH higher than 7, viscosity increases by five orders of magnitude due to the growth of worm-like micelles in length. The findings of this study create pathways for the development of dual semi-interpenetrating polymer-micellar networks, which are highly desired by the petroleum industry. Full article
(This article belongs to the Section Polymer Networks and Gels)
Show Figures

Figure 1

15 pages, 9807 KB  
Article
Investigation of the Tribological Properties of Hybrid Additive-Modified Water-Based Lubricating Fluid
by Raimondas Kreivaitis, Jolanta Treinytė, Artūras Kupčinskas, Milda Gumbytė and Eglė Sendžikienė
Lubricants 2024, 12(5), 178; https://doi.org/10.3390/lubricants12050178 - 15 May 2024
Cited by 4 | Viewed by 1691
Abstract
Water-based lubricating fluids (WBLFs), known for their significant environmental benefits, are the focus of this study. The properties of WBLFs directly influence lubricated mechanisms’ longevity and operating efficiency. WBLFs are enhanced using additives, which must improve their properties and, at the same time, [...] Read more.
Water-based lubricating fluids (WBLFs), known for their significant environmental benefits, are the focus of this study. The properties of WBLFs directly influence lubricated mechanisms’ longevity and operating efficiency. WBLFs are enhanced using additives, which must improve their properties and, at the same time, remain environmentally friendly. This study combines bis(2-hydroxyethyl) ammonium erucate protic ionic liquid and titanium oxide nanoparticles to formulate the hybrid additive. The lubricity was investigated using Alumina/Bearing steel and WC/Bearing steel friction pairs in a reciprocating ball-on-plate tribo-tester. The results show that protic ionic liquid can significantly improve lubricity and the corrosion-preventing ability of the base fluid. Applying a hybrid additive further improved the wear reduction ability in the WC/Bearing steel friction pair. However, the wear reduction ability was diminished when a hybrid additive was used to lubricate the Alumina/Bearing steel friction pair. The proposed lubricity improvement mechanism is based on forming an adsorption layer of ionic liquid molecules and rolling and tribo-sintering titanium oxide nanoparticles. Full article
Show Figures

Figure 1

20 pages, 10787 KB  
Article
Exploration Vectors and Indicators Extracted by Factor Analysis and Association Rule Algorithms at the Lintan Carlin-Type Gold Deposit, Youjiang Basin, China
by Xiaolong Wang, Shengtao Cao, Qinping Tan, Zhuojun Xie, Yong Xia, Lujing Zheng, Jianzhong Liu, Kelin Zhou, Jingdan Xiao and Tingxian Ren
Minerals 2024, 14(5), 492; https://doi.org/10.3390/min14050492 - 7 May 2024
Cited by 4 | Viewed by 1684
Abstract
The Youjiang Basin in China is the world’s second-largest concentrated area of Carlin-type Au deposits after Nevada, USA, boasting cumulative Au reserves nearing 1000 t. This study examined the recently unearthed Lintan Carlin-type Au deposit within the Youjiang Basin. Factor analysis and association [...] Read more.
The Youjiang Basin in China is the world’s second-largest concentrated area of Carlin-type Au deposits after Nevada, USA, boasting cumulative Au reserves nearing 1000 t. This study examined the recently unearthed Lintan Carlin-type Au deposit within the Youjiang Basin. Factor analysis and association rule algorithms were used to identify exploration vectors and indicators essential for navigating this promising geological territory. In the Lintan mining area, the geological strata encompass the Triassic Bianyang, Niluo, and Xuman formations comprised clastic rocks, followed by the deeper Permian Wujiaping Formation with massive carbonate rocks. The orebodies are restricted to the F14 inverse fault, cutting through the Xuman Formation, with an additional F7 fault between the Wujiaping and Xuman formations. A total of 125 rock samples from the F14 fault and a representative cross-section were analyzed for 15 elements (Au, Ag, As, Bi, Cd, Co, Cu, Hg, Mo, Ni, Pb, Sb, Tl, W, and Zn). The elements were divided into four groups based on cluster and factor analysis. Group 1 (Co, Cu, Zn, Ni, Tl, W, and Bi) was mainly enriched in the Xuman, Niluo, and Bianyang formations controlled by sedimentary diagenesis. Group 2 (Au, As, Hg, and Sb) was concentrated in the F14 and F7 faults, representing Au mineralization. Group 3 (Pb, Ag, and Mo) was mostly enriched near the F14 and F7 faults, displaying a peripheral halo of Au mineralization, and was probability controlled by ore-forming hydrothermal activities. Group 4 (Cd and Mo) exhibited extreme enrichment along the periphery of the F7 fault. This pattern indicates the presence of a substantial hydrothermal alteration zone surrounding the fault, likely influenced by ore-forming hydrothermal processes. Additionally, Pb, Ag, Cd, Mo, and W are considered essential indicators for ore formation besides Au, As, Sb, Hg, and Tl. Twelve effective association rules were derived using the association rule algorithm, which can aid in discriminating Au mineralization. The spatial distributions of the 15 elements indicated that the F14 fault is the main ore-bearing fracture zone, while the F7 fault serves as the ore-conducting structure, channeling ore-forming fluids into the F14 fault. Faults between the Wujiaping and Xuman formations, along with their associated reverse faults, present potential prospecting targets both within and outside the Lintan Au deposit in the Youjiang Basin. Exploration geochemical data can be fully utilized by combining factor analysis and association rule algorithms, offering key guidance for prospecting Carlin-type gold and similar deposits. Full article
(This article belongs to the Special Issue Geochemical Exploration for Critical Mineral Resources)
Show Figures

Figure 1

45 pages, 57341 KB  
Article
Multi-Objective Topology Optimization of Conjugate Heat Transfer Using Level Sets and Anisotropic Mesh Adaptation
by Philippe Meliga, Wassim Abdel Nour, Delphine Laboureur, Damien Serret and Elie Hachem
Fluids 2024, 9(5), 105; https://doi.org/10.3390/fluids9050105 - 28 Apr 2024
Cited by 3 | Viewed by 3484
Abstract
This study proposes a new computational framework for the multi-objective topology optimization of conjugate heat transfer systems using a continuous adjoint approach. It relies on a monolithic solver for the coupled steady-state Navier–Stokes and heat equations, which combines finite elements stabilized by the [...] Read more.
This study proposes a new computational framework for the multi-objective topology optimization of conjugate heat transfer systems using a continuous adjoint approach. It relies on a monolithic solver for the coupled steady-state Navier–Stokes and heat equations, which combines finite elements stabilized by the variational multi-scale method, level set representations of the fluid–solid interfaces and immersed modeling of heterogeneous materials (fluid–solid) to ensure that the proper amount of heat is exchanged to the ambient fluid by solid objects in arbitrary geometry. At each optimization iteration, anisotropic mesh adaptation is applied in near-wall regions automatically captured by the level set. This considerably cuts the computational effort associated with calling the finite element solver, in comparison to traditional topology optimization algorithms operating on isotropic grids with a comparable refinement level. Given that we operate within the constraint of a specified number of nodes in the mesh, this allows not only to improve the accuracy of interface representation and motion but also to retain the high fidelity of the numerical solutions at the grid points just adjacent to the interface. Finally, the remeshing and resolution steps both run within a highly parallel environment, which makes it possible for the proposed algorithm to tackle large-scale problems in three dimensions with several tens of millions of state degrees of freedom. The developed solver is validated first by minimizing dissipation in a flow splitter device, for which the method delivers relevant optimal designs over a wide range of volume constraints and flow rate distributions over the multiple outlet orifices but yields better accuracy compared to reference data from literature obtained using uniform meshes (in the sense that the layouts are more smooth, and the solutions are better resolved). The scheme is then applied to a two-dimensional heat transfer problem, using bi-objective cost functionals combining flow resistance and thermal recoverable power. A comprehensive parametric study reveals a complex arrangement of optimal solutions on the Pareto front, with multiple branches of symmetric and asymmetric designs, some of them previously unreported. Finally, the algorithmic developments are substantiated with several three-dimensional numerical examples tackled under fixed weights for heat transfer and flow resistance, for which we show that the optimal layouts computed at low Reynolds number, that are intrinsically relevant to a broad range of microfluidic application, can also serve as smooth solutions to high-Reynolds-number engineering problems of practical interest. Full article
Show Figures

Figure 1

15 pages, 9865 KB  
Article
Reconstruction of Segmental Bone Defect in Canine Tibia Model Utilizing Bi-Phasic Scaffold: Pilot Study
by Dae-Won Haam, Chun-Sik Bae, Jong-Min Kim, Sung-Yun Hann, Chang-Min Richard Yim, Hong-Seok Moon and Daniel S. Oh
Int. J. Mol. Sci. 2024, 25(9), 4604; https://doi.org/10.3390/ijms25094604 - 23 Apr 2024
Cited by 1 | Viewed by 2343
Abstract
The reunion and restoration of large segmental bone defects pose significant clinical challenges. Conventional strategies primarily involve the combination of bone scaffolds with seeded cells and/or growth factors to regulate osteogenesis and angiogenesis. However, these therapies face inherent issues related to immunogenicity, tumorigenesis, [...] Read more.
The reunion and restoration of large segmental bone defects pose significant clinical challenges. Conventional strategies primarily involve the combination of bone scaffolds with seeded cells and/or growth factors to regulate osteogenesis and angiogenesis. However, these therapies face inherent issues related to immunogenicity, tumorigenesis, bioactivity, and off-the-shelf transplantation. The biogenic micro-environment created by implanted bone grafts plays a crucial role in initiating the bone regeneration cascade. To address this, a highly porous bi-phasic ceramic synthetic bone graft, composed of hydroxyapatite (HA) and alumina (Al), was developed. This graft was employed to repair critical segmental defects, involving the creation of a 2 cm segmental defect in a canine tibia. The assessment of bone regeneration within the synthetic bone graft post-healing was conducted using scintigraphy, micro-CT, histology, and dynamic histomorphometry. The technique yielded pore sizes in the range of 230–430 μm as primary pores, 40–70 μm as secondary inner microchannels, and 200–400 nm as tertiary submicron surface holes. These three components are designed to mimic trabecular bone networks and to provide body fluid adsorption, diffusion, a nutritional supply, communication around the cells, and cell anchorage. The overall porosity was measured at 82.61 ± 1.28%. Both micro-CT imaging and histological analysis provided substantial evidence of robust bone formation and the successful reunion of the critical defect. Furthermore, an histology revealed the presence of vascularization within the newly formed bone area, clearly demonstrating trabecular and cortical bone formation at the 8-week mark post-implantation. Full article
(This article belongs to the Special Issue Recent Development in Scaffolds for Tissue Engineering)
Show Figures

Figure 1

28 pages, 88276 KB  
Article
Improved Mel Frequency Cepstral Coefficients for Compressors and Pumps Fault Diagnosis with Deep Learning Models
by Diego Cabrera, Ruben Medina, Mariela Cerrada, René-Vinicio Sánchez, Edgar Estupiñan and Chuan Li
Appl. Sci. 2024, 14(5), 1710; https://doi.org/10.3390/app14051710 - 20 Feb 2024
Cited by 7 | Viewed by 2183
Abstract
Compressors and pumps are machines frequently used in petroleum and chemical industries for fluid transportation through flow systems to keep industrial processes running permanently. As their failure can produce costly disruption, developing fault detection and diagnosis tools is essential for accurately detecting and [...] Read more.
Compressors and pumps are machines frequently used in petroleum and chemical industries for fluid transportation through flow systems to keep industrial processes running permanently. As their failure can produce costly disruption, developing fault detection and diagnosis tools is essential for accurately detecting and diagnosing faults. This research proposes a bi-dimensional representation of the vibration signal corresponding to the Mel Frequency Cepstral Coefficients (MFCC) and their first two derivatives as features. The pseudo-periodic nature of the fault signature in rotating machines is exploited to put forward an efficient and accurate patch-wise fault classification method. This approach enables the classification of 13 combined types of faults in a multi-stage centrifugal pump and 17 faults in a reciprocating compressor. Classification is performed using the Long Short-Term Memory (LSTM) network, the bidirectional Long Short-Term Memory (BiLSTM) neural network, and the Convolutional Neural Network (CNN). Accurate classification over 99% is attained, showing that the proposed feature extraction procedure correctly classifies a large set of faults simultaneously appearing in such rotating machines. Full article
(This article belongs to the Section Acoustics and Vibrations)
Show Figures

Figure 1

53 pages, 5520 KB  
Review
An Overview of the Recent Advances in Pool Boiling Enhancement Materials, Structrure, and Devices
by José Pereira, Reinaldo Souza, Rui Lima, António Moreira and Ana Moita
Micromachines 2024, 15(2), 281; https://doi.org/10.3390/mi15020281 - 17 Feb 2024
Cited by 6 | Viewed by 3958
Abstract
This review attempts to provide a comprehensive assessment of recent methodologies, structures, and devices for pool boiling heat transfer enhancement. Several enhancement approaches relating to the underlying fluid route and the capability to eliminate incipient boiling hysteresis, augment the nucleate boiling heat transfer [...] Read more.
This review attempts to provide a comprehensive assessment of recent methodologies, structures, and devices for pool boiling heat transfer enhancement. Several enhancement approaches relating to the underlying fluid route and the capability to eliminate incipient boiling hysteresis, augment the nucleate boiling heat transfer coefficient, and improve the critical heat flux are assessed. Hence, this study addresses the most relevant issues related to active and passive enhancement techniques and compound enhancement schemes. Passive heat transfer enhancement techniques encompass multiscale surface modification of the heating surface, such as modification with nanoparticles, tunnels, grooves, porous coatings, and enhanced nanostructured surfaces. Also, there are already studies on the employment of a wide range of passive enhancement techniques, like displaced enhancement, swirl flow aids, and bi-thermally conductive surfaces. Moreover, the combined usage of two or more enhancement techniques, commonly known as compound enhancement approaches, is also addressed in this survey. Additionally, the present work highlights the existing scarcity of sufficiently large available databases for a given enhancement methodology regarding the influencing factors derived from the implementation of innovative thermal management systems for temperature-sensitive electronic and power devices, for instance, material, morphology, relative positioning and orientation of the boiling surface, and nucleate boiling heat transfer enhancement pattern and scale. Such scarcity means the available findings are not totally accurate and suitable for the design and implementation of new thermal management systems. The analysis of more than 100 studies in this field shows that all such improvement methodologies aim to enhance the nucleate boiling heat transfer parameters of the critical heat flux and nucleate heat transfer coefficient in pool boiling scenarios. Finally, diverse challenges and prospects for further studies are also pointed out, aimed at developing important in-depth knowledge of the underlying enhancement mechanisms of such techniques. Full article
(This article belongs to the Special Issue Feature Reviews in Micromachines 2023)
Show Figures

Figure 1

Back to TopTop