Search Results (205)

Under the ideas of ‘hinges’ and ‘pictures’, as these relate to deep disagreement, Wittgenstein’s view of religious belief is a multifaceted challenge to conceptions of thought-world relations. In this article, I discuss Cora Diamond’s analysis of this challenge. Diamond herself is not particularly interested in hinges; I try to understand why. I first bring in a discussion between Michael Williams and Duncan Pritchard on how to read On Certainty. This allows me to identify Diamond’s perspective on deep disagreement and pictures: she concentrates on making sense, and not directly on knowledge. To further clarify her perspective, I introduce Hilary Putnam’s reading of the Lectures on Religious Belief, which proposes a cognitivist view of religion as ethics, centering on the notion of picture. Although Diamond is close to Putnam, for her, the most important challenge posed by religious belief lies not with epistemological issues of rational versus arational grounds of belief, or cognitivism versus non-cognitivism in ethics, but rather in making us drop the Fregean (and Tractarian) idea of the thinkableness of all thoughts, making place for ‘irreplaceable pictures’. I end by suggesting that Diamond’s analysis sheds light on often uncontested assumptions about the natures of thought and communication. Full article

This paper examines the philosophy of language in The Platform Sutra of the Sixth Patriarch (六祖壇經), demonstrating its centrality to Zen Buddhism and Buddhist sinicization. The sutra emphasizes the ineffability of ultimate truth (至道無言) and the principle that words falter in encapsulating the Dao (言語道斷), framing language as a provisional “raft” (筏) that must be instrumentalized yet transcended through a dialectic of employing and abandoning (用離辯證). It ontologically grounds this view in Buddha-nature’s (佛性) pre-linguistic essence, advocating transcending reliance on words and letters (不假文字) while strategically deploying language to dismantle its own authority. Historically, this constituted a revolt against Tang scholasticism’s textual fetishism. The text adopts a dynamic dialectic, neither clinging to nor rejecting language, exemplified by Huineng’s awakening through the Diamond Sutra, where recitation catalyzes internal insight. Operationally, it utilizes negational discourse, the “Two Paths Mutually Condition” method (二道相因) embedded in the “Twelve Pairs of Dharmic Forms” (法相語言十二對) in particular, to systematically deconstruct dualisms, while promoting embodied unity of speech, mind, and action (口念心行) to critique empty recitation. Ultimately, the sutra orchestrates language as a self-subverting medium: balancing acknowledgment of its limitations with pragmatic instrumentality, it presents an Eastern paradigm where language actively disrupts conceptual fetters to facilitate direct insight into Buddha-nature, reframing it as a dynamic catalyst for “illuminating the mind and seeing one’s nature” (明心見性). Full article

The paper shows the effect of using a lubricant in the form of an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF₆), on the tribological properties of a hydrogenated diamond-like coating (DLC) doped with tungsten a-C:H:W. The coatings were deposited on 100Cr6 steel by plasma-enhanced chemical vapor deposition PECVD. Tribological tests were carried out on a TRB³ tribometer in a rotary motion in a ball–disc combination. 100Cr6 steel balls were used as a counter-sample. Friction and wear tests were carried out for discs made of 100Cr6 steel and 100Cr6 steel discs with a DLC coating. They were performed under friction conditions with and without lubrication under 10 N and 15 N loads. The ionic liquid BMIM-PF₆ was used as a lubricant. Coating thickness was observed on a scanning microscope, and the linear analysis of chemical composition on the cross-section was analyzed using the EDS analyzer. The confocal microscope with an interferometric mode was used for analysis of the geometric structure of the surface before and after the tribological tests. The contact angle of the samples for distilled water, diiodomethane and ionic liquid was tested on an optical tensiometer. The test results showed good cooperation of the DLC coating with the lubricant. It lowered the coefficient of friction in comparison to steel about 20%. This indicates the synergistic nature of the interaction: DLC coating–BMIM-PF₆ lubricant–100Cr6 steel. Full article

Purpose: The aim of this study was to compare the effect of rotary (air-driven, electric-driven) and oscillating (piezoelectric ultrasonic) handpieces on the quality of crown preparation, marginal integrity, and internal adaptation of monolithic zirconia crowns. Materials and Methods: Seventy-two standardized premolar preparations were performed using the air-driven handpiece with a guide pin-ended tapered fissure diamond bur on a modified dental surveyor. The finishing process utilized three handpiece types (n = 24/group) with fine/superfine diamond burs under controlled force with a fixed number of rotations and controlled advancement time. Marginal/internal adaptation was evaluated via the triple-scan technique; defects (marginal, axial, and occlusal) were quantified based on predefined criteria through the inspection of the Standard Tessellation Language (STL) file. Results: One-way ANOVA with Tukey HSD and Kruskal–Wallis with Dunn–Bonferroni tests were utilized. The marginal gap showed no significant differences (p > 0.05, η² = 0.04). The electric handpiece outperformed the ultrasonic (p = 0.023, η² = 0.105) in internal adaptation, while the air-driven showed no differences (p > 0.05). The ultrasonic handpiece produced fewer marginal defects than the air-driven (p = 0.039, ε² = 0.132), but more axial defects (median 9 vs. 6, p = 0.014, ε² = 0.168) than the electric handpiece and occlusal defects (5 vs. 3, 4 p = 0.007, p = 0.015, ε² = 0.227) than rotary handpieces. The air-driven handpiece exhibited comparable defect numbers to the electric handpiece without statistical significance (p > 0.05). Conclusions: Handpiece selection had a small effect on marginal adaptation but more pronounced effects on overall defect formations and internal adaptation. The ultrasonic handpiece’s decreased marginal defects but variable axial/occlusal results reveal technological constraints, whereas rotary handpieces’ consistency reflects their operator-dependent nature. Full article

Background: The Port of Santa Marta, located on Colombia’s northern Caribbean coast, plays a vital role in the country’s maritime trade, particularly in the export of agricultural and perishable goods. This raises the question: how competitive is Santa Marta’s container terminal compared to national and regional ports, and what strategic factors shape its performance within the Colombia and Latin American maritime logistics system? Methods: This study evaluates the port’s competitiveness by applying Porter’s Extended Diamond Model. A mixed-methods ap-proach was employed, combining structured surveys and interviews with port stakeholders and operational data analysis. A competitiveness matrix was developed and examined using standardized residuals and L1 regression to identify critical performance gaps and strengths. Results: The analysis reveals several competitive advantages, including the port’s strategic location, natural deep-water access, and advanced infrastructure for refrigerated cargo. It also benefits from skilled labour and proximity to global shipping routes, such as the Panama Canal. Nonetheless, challenges remain in storage capacity, limited road connectivity, and insufficient public investment in hinterland infrastructure. Conclusions: While the Port of Santa Marta shows strong maritime capabilities and spe-cialized services, addressing its land-side and institutional constraints is essential for positioning it as a resilient, competitive logistics hub in the Latin American and Caribbean region. Full article

This paper presents a study on optimising self-brazing powder mixtures for powder metallurgy diamond tools, specifically focusing on wire saws used in cutting natural stone. The research aimed to understand the relationship between the chemical composition of powder mixtures and the hardness of the sintered matrix. The experimental process involved the use of various commercially available powders, including carbonyl iron, carbonyl nickel, atomised bronze, atomised copper, and ferrophosphorus. The samples made of different powder mixtures were compacted and sintered and then characterised by dimensional change, density, porosity, and hardness. The obtained results were statistically analysed using an analysis of variance (ANOVA) tool to create linear regression models that relate the material properties to their chemical composition. The investigated materials exhibited excellent sintering behaviour and very low porosity, which are beneficial for diamond retention. Very good sinterability of powder mixtures can be achieved by tin bronze addition, which provides a sufficient content of the liquid phase and promotes the shrinkage during sintering. Statistical analysis revealed that hardness was primarily affected by phosphorous content, with nickel having a lesser but still significant impact. The statistical model can predict the hardness of the matrix based on its chemical composition. This model, with a determination coefficient of approximately 80%, can be valuable for developing new metal matrices for diamond-impregnated tools, particularly for wire saw beads production. Full article

Carbon is one of nature’s basic elements, hosting a tremendous number of allotropes benefiting from its capacity to generate $sp$, $s{p}^2$, and $s{p}^3$ hybridized carbon–carbon bonds. The exploration of novel carbon architectures has remained a pivotal focus in the fields of condensed matter physics and materials science for an extended period. In this paper, we, by using first-principles calculation, carry on a detailed investigation an an all-$s{p}^3$ hybridized carbon structure in a 20-atom tetragonal unit cell with $P{4}_3{2}_{1}2$ symmetry ($D_4^8$, space group No. 96), and call it T20 carbon. The equilibrium energy of T20 carbon is −8.881 eV/atom, only 0.137 eV/atom higher than that of diamond, indicating that T20 is a superstable carbon structure. T20 is also a superhard carbon structure with a large Vicker’s hardness about 83.5 GPa. The dynamical stability of T20 was verified by means of phonon band spectrum calculations. Meanwhile, its thermal stability up to 1000 K was verified via ab initio molecular dynamics simulations. T20 is an indirect band-gap insulator with approximately 5.80 eV of a band gap. This value is obviously greater than the value in the diamond (5.36 eV). Moreover, the simulated X-ray diffraction pattern of T20 displays a remarkable match with the experimental data found in the milled fullerene soot, evidencing that T20 may be a potential modification discovered in this experimental work. Our work has given a systematical understanding on an all-$s{p}^3$ hybridized superstable and superhard carbon allotrope with large band gap and provided a very competitive explanation for previous experimental data, which will also provide guidance for upcoming studies in theory and experiment. Full article

In recent years, polycrystalline diamond compact (PDC) drill bits have seen significant advancements. They have replaced over 90% of the workload traditionally handled by roller cone bits and have become the predominant choice in energy drilling due to their superior efficiency and durability. However, PDC drill bits are susceptible to adhesion of rock cuttings during drilling in muddy formations, leading to mud accumulation on the bit surface. This phenomenon can cause drill bit failure and may contribute to downhole complications, including tool failure and borehole instability. The adhesion issue between PDC drill bits and mud rock cuttings underground is primarily influenced by the normal adhesion force between the drill bit surface and the mud rock cuttings. Therefore, biological non-smooth surface technology is applied to the prevention and control of drill bit balling. It is an optimal selection of biomimetic non-smooth surface structures with reduced adhesion and detachment properties. A non-smooth surface model for the PDC drill bit body is established through the analysis of the morphological characteristics of natural biological non-smooth surfaces. An experimental platform is designed and manufactured to evaluate the adhesion performance of non-smooth surface specimens. Indoor experiments are conducted to test the normal adhesion force of non-smooth surface specimens under varying morphologies, sizes, and contact times with clay. Finally, the anti-adhesion performance of the non-smooth surface unit structures is then analyzed. The normal adhesion force with a contact time of 12 h is as follows: 340 Pa of big square raised, 250 Pa of middle square raised, 190 Pa of small square raised, 315 Pa of big circular groove, 280 Pa of middle circular groove, 200 Pa of small circular groove, 225 Pa of big dot pit, 205 Pa of middle dot pit, and 130 Pa of small dot pit. Compared with the normal adhesion force of 550 Pa for smooth surface specimens with a contact time of 12 h, the anti-adhesion properties of the three non-smooth surface unit structure specimens designed in this paper were verified. We analyzed the anti-adhesion performance of non-smooth surface unit structures. At the critical contact time when the adhesion force tends to stabilize, the adhesion forces of different specimens are as follows: 330 Pa of big square raised, 237.5 Pa of middle square raised, 175 Pa of small square raised, 290 Pa of big circular groove, 250 Pa of middle circular groove, 160 Pa of small circular groove, 210 Pa of big dot pit, 185 Pa of middle dot pit, and 115 Pa of small dot pit. The results indicate that the anti-adhesion effect of small dot pit structures is the most effective, while the anti-adhesion effect of large square convex structures is the least effective. As the size of the unit structure decreases, it becomes more similar to the surface size of the organism. Additionally, a shorter contact time with clay leads to a better anti-adhesion effect. These findings provide new insights and research directions for the effective prevention and control of mud wrapping on PDC drill bits. Full article

Superdeep diamonds and their syngenetic inclusions are crucial for understanding Earth’s deep carbon cycle and slab–mantle redox dynamics. The origins of these diamonds, especially their links to iron (Fe) carbides and ferropericlase with varying Mg# [=Mg/(Mg+Fe)_at], however, remain elusive. In this study, we performed high pressure–temperature (P-T) experiments (10–16 GPa and 1200–1700 K) across cold-to-warm subduction zones using a multi-anvil press. The results reveal a stepwise Fe-mediated carbonate reduction process for the formation of superdeep diamonds: MgCO₃ → Fe-carbides (Fe₃C/Fe₇C₃) → graphite/diamond. This mechanism explains two phenomena regarding superdeep diamonds: (1) anomalous ¹³C depletion results from kinetic isotope fractionation during ¹²C enrichment into the intermediate Fe-carbides; (2) nitrogen scarcity is due to Fe-carbides acting as nitrogen sinks. Ferropericlase [(Mg,Fe)O] formed during the reactions in our experiments shows Mg# variations (0.2–0.9), similar to those found in natural samples. High Mg# (>0.7) variants from lower temperature experiments indicate diamond crystallization from carbonatitic melts in the shallow lower mantle, while the broad Mg# range (0.2–0.9) from experiments at higher temperatures suggests multi-depth formation processes as found in Brazilian diamonds. These findings suggest that slab–mantle interactions produce superdeep diamonds with distinctive Fe-carbides and ferropericlase assemblages as inclusions, coupled with their ¹³C- and nitrogen-depleted signatures, which underscore thermochemical carbon cycling as a key factor in deep carbon storage and mantle mineralogy. Full article

In this study, the voltammetric behavior of apocynin on a boron-doped diamond electrode in a phosphate buffer (pH 7.3) has been reported for the first time. The oxidation process is quasi-reversible, diffusion-controlled, and involves one electron and one proton. The product of the electrode reaction is an unstable radical that undergoes successive chemical transformations near the working electrode. The proposed mechanism of this process can be described as E_qC_i and served as the basis for the development of a new voltammetric method for determining apocynin in natural samples. The analytical signal was the anodic peak on DPV curves at a potential of 0.605 V vs. Ag/AgCl. A linear response was observed in the concentration range of 0.213–27.08 mg L⁻¹. The estimated LOD and LOQ values were 0.071 and 0.213 mg L⁻¹, respectively. The effectiveness of the method was demonstrated both in control determinations and in the analysis of the dietary supplement. This procedure is simple, fast, sensitive, selective, and requires no complicated sample preparation, which is limited only to a simple extraction with ethanol. The low consumption of non-toxic reagents makes it environmentally friendly. To the best of our knowledge, this is the first presentation of a voltammetric procedure to determine this analyte studied in a phosphate buffer solution on a boron-doped diamond electrode. It can also be easily adapted to determine other phenolic compounds with antioxidant properties in various matrices. Full article

Composite grids serve as reinforcement in concrete structures, offering alternatives to conventional steel reinforcement. These grids can be fabricated from various materials, including synthetic polymers, metals, and natural fibers. This study explores the use of composite grids as lateral confinement of self-compacting concrete (SCC) cylinders and examines their impact on the failure mode under axial compression. In the experiment, the types of grids and mesh shapes used were plastic grids of diamond mesh (PGD) and regular mesh (PGT), metallic grids of diamond mesh (MGD) and square mesh (MGS), vegetable grids of Alfa fiber mesh, 10 × 10 mm (VGAF-1) and 20 × 20 mm (VGAF-2), and vegetable grids of date palm fibers (VGDF). The binder of SCC mixtures incorporated 10% marble powder as a partial replacement for ordinary Portland cement (OPC). SCC mixtures were tested in the fresh state by measuring the slump flow diameter, V-funnel flow time, L-box blocking ratio, and segregation index. Cylinders with a diameter of 160 mm and a height of 320 mm were made to assess the mechanical properties of hardened SCC mixtures under axial compression. The results indicate that most of the confined cylinders exhibited an increase in ductility compared to unconfined cylinders. Grid types MGD and PGD provided the best performance, with ductility increases of 100.33% and 96.45%, respectively. VGAF-2 cylinders had greater compressive strength than cylinders with other grid types. The findings revealed that the type and mesh shape of the grids affects the failure mode of confined cylinders, but has minimal influence on their modulus of elasticity. This study highlights the potential of lateral grid confinement as a technique for rehabilitating, strengthening, and reinforcing weaker structural concrete elements, thereby improving their mechanical properties and extending the service life of building structures. Full article

Laparoscopic lens fogging and contamination pose significant challenges, leading to a reduced surgical field of view. Intraoperative cleaning to address these issues extends the surgical duration and elevates the risk of surgical site infections. The authors propose that a hydrophilic diamond-like carbon (DLC) coating would effectively mitigate fogging and fouling, thereby eliminating the requirement for intraoperative cleaning, while the scratch-resistant nature of DLC would provide additional benefits. The present study investigates the efficacy of aluminum oxide (Al₂O₃) as a dopant in diamond-like carbon (DLC) films for antifogging applications. The authors hypothesized that adding oxygen to the DLC matrix would increase surface energy by increased hydrogen bonding, resulting in a highly hydrophilic coating. Varying dopant concentrations were tested to observe their effects on hydrophilicity, transparency, biocompatibility, and wear properties. The doped films displayed a notable improvement in transparency throughout the visible spectrum. Plasma-cleaned samples demonstrated a substantial reduction in contact angles, achieving values less than 8°. The biocompatibility of these films was analyzed with CellTiter-Glo assays; the films demonstrated statistically similar levels of cell viability when compared to the control media. The absence of adenosine triphosphate released by blood platelets in contact with the DLC coatings suggests in vivo hemocompatibility. These films, characterized by high transparency, biocompatibility, and biostability, could be valuable for biomedical applications necessitating transparent coatings. Full article

The fraud triangle has long served as a fundamental model for understanding corporate fraud, emphasizing opportunity, pressure, and rationalization. Over time, this framework evolved with the fraud diamond, which introduced capability; the fraud pentagon, which added arrogance; and the fraud hexagon, which incorporated collusion and reshaped arrogance. Building on these developments, this study proposes a seventh dimension: the pleasure and thrill of risk-taking. This psychological factor highlights the gratification that some individuals derive from engaging in fraud as a high-stakes game. Through a qualitative analysis of five major corporate fraud cases—Société Générale, Enron, Wirecard, Parmalat, and Theranos—this study highlights the presence of this additional motivational factor. By introducing the fraud polygon, this research provides a more comprehensive framework for understanding corporate fraud’s multifaceted nature. This model has significant implications for both academic research and practical fraud prevention, offering insights into the interplay between systemic vulnerabilities and intrinsic motivations. Full article

Environmental challenges, high safety risks and operational inefficiencies are some of the issues facing the mining sector. The paper offers an integrated viewpoint to address these issues by combining swarm robotics, nature-inspired algorithms (NIAs) and other biomimicry-based technologies into a single framework. It presents a systematic classification of each methodology, emphasizing their key advantages and disadvantages as well as considering real-life mining application scenarios, including hazard detection, autonomous transportation and energy-efficient drilling. Case studies are citied to demonstrate how these methodologies work together, and an extensive comparison table considering their applications at mines, such as Boliden, Diavik Diamond Mine, Olympic Dam and others, presents a summary of their scalability and practicality. This paper highlights future directions such as multi-robot coordination and hybrid NIAs, to improve operational resilience and sustainability. It also provides a broad overview of biomimicry and critically examines unresolved issues like real-time adaptation, parameter tuning and mechanical wear. The paper aims to offer a comprehensive insight into using bio-inspired models to enhance mining efficiency, safety and environmental management, while proposing a road map for resolving the issues that continue to be a hurdle for wide adaptation of these technologies in the mining industry. Full article

In recent years, the pollutant sulfamethoxazole (SMX) that is widely used in medical therapy has been frequently detected in different water systems. Thereby, it is necessary to develop green and effective advanced oxidation strategies, especially the electro-oxidation process. In this study, an electro-oxidation system featuring a boron-doped diamond (BDD) anode and NaCl as the supporting electrolyte was implemented to effectively remove sulfamethoxazole (SMX) without the addition of external oxidants. The operational parameters were optimized using the response surface methodology with a pH 7.5, current density of 4.44 mA/cm², and NaCl concentration of 20 mmol/L. The optimization significantly enhanced the degradation efficiency of SMX to obtain 100% removal in 5 min. Results of scavenging and chemical probe experiments indicated the presence of hydroxyl radicals (^•OH) and chlorine radicals (Cl^•), with the latter primarily forming between the reaction of Cl⁻ and ^•OH. A competition experiment further revealed the relative oxidative contribution of Cl^• of 38.6%, highlighting its significant role in the degradation process. Additionally, ion chromatography analysis confirmed the presence of Cl^• without the formation of harmful by-products such as ClO₄⁻, affirming the environmentally friendly nature of the system. The toxicity of the degradation by-products was also assessed. The application of current was investigated to explore the influence of coexistence ions as well as repeatability. Overall, this work highlighted the effectiveness of the electro-oxidation system for the degradation of organic pollutants in saline wastewater, demonstrating the significance of optimization of operational parameters for efficient and sustainable environmental remediation. Full article