Search

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Diamond & Abrasives Engineering is the property of Zhengzhou Research Institute for Abrasives & Grinding and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mining diamond poses significant and potentially underestimated risks to the environment worldwide. Here, we propose a Diamond Environmental Impacts Estimation (DEIE) model to forecast the environmental indicators, including greenhouse gas (GHG) emissions, mineral waste, and water usage of the diamond industry from 2030 to 2100 in the top diamond production countries under different Shared Socio-economic Pathways (SSPs). The DEIE projection results indicate that the annual GHG emissions, mineral waste, and water usage of the global diamond industry will reach 9.65 Mt, 422.80 Mt, and 78.68 million m3 under the SSP1-1.9 scenario, and 13.26 Mt, 582.84 Mt, and 107.95 million m3 under the SSP2-2.6 scenario in 2100, respectively. We analyze the environmental impact heterogeneities and the associated driving factors across the major diamond production countries identified by our DEIE framework. In addition, we find that lab-grown diamonds can reduce annual GHG emissions, mineral waste, and water usage by 9.58 Mt, 421.06 Mt, and 66.70 million m3 in 2100. The lab-grown diamond substitution policy can annually save 714 million cubic meters of landfill space, harvest 255 million kilograms of rice, feed 436 million people, and lift 1.19 million households out of hunger. The lab-grown diamond substitution policy could contribute to the diamond industry's GHG mitigation and sustainability efforts in a cost-saving manner. [ABSTRACT FROM AUTHOR]

Diamond color centers have proven to be versatile quantum emitters and exquisite sensors of stress, temperature, electric and magnetic fields, and biochemical processes. Among color centers, the silicon-vacancy (SiV-) defect exhibits high brightness, minimal phonon coupling, narrow optical linewidths, and high degrees of photon indistinguishability. Yet the creation of reliable and scalable SiV--based color centers has been hampered by heterogeneous emission, theorized to originate from surface imperfections, crystal lattice strain, defect symmetry, or other lattice impurities. Here, we advance high-resolution cryo-electron microscopy combined with cathodoluminescence spectroscopy and 4D scanning transmission electron microscopy (STEM) to elucidate the structural sources of heterogeneity in SiV- emission from nanodiamond with sub-nanometer-scale resolution. Our diamond nanoparticles are grown directly on TEM membranes from molecular-level seedings, representing the natural formation conditions of color centers in diamond. We show that individual subcrystallites within a single nanodiamond exhibit distinct zero-phonon line (ZPL) energies and differences in brightness that can vary by 0.1 meV in energy and over 70% in brightness. These changes are correlated with the atomic-scale lattice structure. We find that ZPL blueshifts result from tensile strain, while ZPL red shifts are due to compressive strain. We also find that distinct crystallites host distinct densities of SiV- emitters and that grain boundaries impact SiV- emission significantly. Finally, we interrogate nanodiamonds as small as 40 nm in diameter and show that these diamonds exhibit no spatial change to their ZPL energy. Our work provides a foundation for atomic-scale structure-emission correlation, e.g., of single atomic defects in a range of quantum and two-dimensional materials. [ABSTRACT FROM AUTHOR]

Zimbabwe possesses abundant mineral resources, which could propel the country's economic growth if they are properly beneficiated to produce value- added products. However, the country has failed to leverage its mineral endowment to drive sustainable socioeconomic transformation. This study aimed to evaluate the viability of mineral beneficiation in Zimbabwe's mining sector by analysing the factors that affect its competitiveness and identifying strategic interventions to improve the industry's competitiveness. The study employed Michael Porter's Diamond Model of industry competitiveness to analyse the mining industry's competitiveness in Zimbabwe and to assess the model's applicability in the country's context. The study findings reveal that Zimbabwe's mining sector is not currently competitive and does not facilitate mineral beneficiation. Additionally, the study finds that the Porter Diamond Model is not entirely relevant to the Zimbabwean context because it is primarily applicable to developed nations. The study recommends strategic interventions that could transform Zimbabwe's comparative advantage in the mining sector into a competitive advantage. [ABSTRACT FROM AUTHOR]

Hot filament CVD method, which is used to synthesize high efficiency and high quality superhard abrasives, has become a research hotspot. Based on a new multi-piece grid substrate, which can increase the single deposition yield of micro-powder, and FLUENT, the fluid simulation software, the traditional model is optimized with unchanged number of single outlet and stable total intake flow but the single inlet is split into five equally sized inlet. The number and the arrangement of inlets that affect the process uniformity are simulated. The physical field of gas in the HFCVD system is compared and analyzed. Results show that the four optimized models all perform improved uniformity of substrate temperature and flow rate, which is conducive to the uniform growth of diamond single crystal particles, but the effect of diamond deposition rate is not significant. Further analysis on the temperature field of the optimized model indicates that the temperature difference of the system is the lowest with five inlets located in the middle top and a single outlet in the middle bottom of the reaction chamber, which satisfies the condition of uniform growth of diamond single crystal particles on multi-piece silicon substrate. Finally, CVD single crystal diamond particles are deposited to verify the reliability of the simulation. [ABSTRACT FROM AUTHOR]

In order to solve the problem that it is difficult to grow diamond films with high binding force on the surface of high cobalt cemented carbide, the Cr/CrSiN film was used as the transition layer, and the nanocrystalline diamond films (NCD), the submicrocrystalline diamond films (SMCD) and the microcrystalline diamond films (MCD) were deposited on the cemented carbide by hot filament chemical vapor deposition method, and their binding forces were studied. The results show that the Cr/CrSiN transition layer can be used to deposit diamond films with excellent bonding strength on the surface of high cobalt cemented carbide. NCD has the best binding force, followed by SMCD, and MCD has the worst binding force. When the grain size of the diamond film increases, the bonding forces of the diamond film weaken due to the poor toughness of the diamond films and severe carbonization of the transition layer. When the crystal size of the diamond film increases, the binding force of the diamond film becomes weak due to the poor toughness of the diamond film and serious carbonization of the transition layer. [ABSTRACT FROM AUTHOR]

This case study of the gem-diamond industry applies the lens of game theory to explore how the adoption of blockchain technology can be achieved throughout a supply chain. We identify strategies that blockchain providers and beneficiaries in the case study have used or, in some cases, could have used to create a game-theoretic equilibrium across supply chain participants, resulting in the end-to-end adoption of a blockchain solution. We review the benefits that such a solution provides to the ultimate consumer and to supply-chain participants. [ABSTRACT FROM AUTHOR]