Exploring the transformation of spatial mechanisms from their unfolded to controlled folding states to meet the requirements of various application scenarios has long been a hot topic in mechanical ...structure research. Although conventional spatial mechanisms can be designed to meet almost any application scenario, the design’s complex and excessive combinations of structural components, kinematic pairs, and drive units are unavoidable. It introduces many problems, such as poor reliability, drive complexity, and control difficulties. Based on 4D printing technology, the design of self-folding spatial mechanisms that use pre-stressed response properties under predetermined thermal excitation to achieve different shrinkage ratios integrates the control and drive system and the structural components and kinematic pairs. It brings novel features of self-folding while effectively avoiding many problems associated with conventional mechanical design. Further, the pre-stressed response model introduces the self-folding spatial mechanisms’ excitation, morphing, and driving investigation. Self-folding spatial mechanisms with different shrinkage ratios were prepared via fused deposition modeling, which verified the theoretical analysis and pre-stress response model and the design’s correctness and feasibility by experiments. The existing 4D printing technology lacks a paradigmatic design method in the application field. Contrarily, this work organically combined the conventional mechanical structure design with materials and fabrication via fused deposition modeling. A systematic study of self-folding spatial mechanisms from structural design to morphing control was carried out. This design is expected to introduce a novel paradigm of 4D printing technology in conventional mechanical design and has considerable application prospects in spherical radar calibration mechanisms.
The use of non-smart materials in structural components and kinematic pairs allows for flexible assembly in practical applications and is promising for aerospace applications. However, this approach ...can result in a complex structure and excessive kinematic pairs, which limits its potential applications due to the difficulty in controlling and actuating the mechanism. While smart materials have been integrated into certain mechanisms, such integration is generally considered a unique design for specific cases and lacks universality. Therefore, organically combining universal mechanism design with smart materials and 4D printing technology, innovating mechanism types, and systematically exploring the interplay between structural design and morphing control remains an open research area. In this work, a novel form-controlled planar folding mechanism is proposed, which seamlessly integrates the control and actuation system with the structural components and kinematic pairs based on the combination of universal mechanism design with smart materials and 4D printing technology, while achieving self-controlled dimensional ratio adjustment under a predetermined thermal excitation. The design characteristics of the mechanism are analyzed, and the required structural design parameters for the preprogrammed design are derived using a kinematic model. Using smart materials and 4D printing technology, folding programs based on material properties and control programs based on manufacturing parameters are encoded into the form-controlled rod to achieve the preprogrammed design of the mechanism. Finally, two sets of prototype mechanisms are printed to validate the feasibility of the design, the effectiveness of the morphing control programs, and the accuracy of the theoretical analysis. This mechanism not only promotes innovation in mechanism design methods but also shows exceptional promise in satellite calibration devices and spacecraft walking systems.
Phytomining is a sustainable approach that uses hyperaccumulators for critical element extraction from various substrates, such as contaminated soils, mine tailings, and aqueous solutions. In this ...study, grass seeds were fed with a solution containing Y, La, Ce, and Dy, resulting in around 510 mg/kg (dry basis) of total rare earth elements (TREEs) accumulated in grass leaves. Electron probe microanalyzer (EPMA) analysis showed that rare earth elements (REEs) in the grass leaves (GL) predominantly complexed with phosphorous (P). Around 95% of Y, 93% of La, 92% of Ce, and 93% of Dy were extracted from the GL using 0.5 mol/L H2SO4 at a solid concentration of 5 wt.%. Subsequently, microwave-assisted hydrothermal carbonization (MHTC) was used to convert the leaching residue into hydrochar to achieve a comprehensive utilization of GL biomass. The effect of temperature on the structural properties and chemical composition of the resulting hydrochar was evaluated. Scanning electron microscopy (SEM) analysis revealed that the original structure of GL was destroyed at 180 °C during MHTC, producing numerous microspheres and pores. As the reaction temperature increased, there was a concurrent increase in carbon content, a higher heating value (HHV), and energy densification, coupled with a decrease in the hydrogen and oxygen contents of hydrochar. The evolution of H/C and O/C ratios indicated that dehydration and decarboxylation occurred during MHTC. The results showed that the waste biomass of the GL after REE extraction can be effectively converted into energy-rich solid fuel and low-cost adsorbents via MHTC.
The regeneration of weight-bearing bone defects and critical-sized cartilage defects remains a significant challenge. A wide range of nano-biomaterials are available for the treatment of ...bone/cartilage defects. However, their poor compatibility and biodegradability pose challenges to the practical applications of these nano-based biomaterials. Natural biomaterials inspired by the cell units (e.g., nucleic acids and proteins), have gained increasing attention in recent decades due to their versatile functionality, compatibility, biodegradability, and great potential for modification, combination, and hybridization. In the field of bone/cartilage regeneration, natural nano-based biomaterials have presented an unparalleled role in providing optimal cues and microenvironments for cell growth and differentiation. In this review, we systematically summarize the versatile building blocks inspired by the cell unit used as natural nano-based biomaterials in bone/cartilage regeneration, including nucleic acids, proteins, carbohydrates, lipids, and membranes. In addition, the opportunities and challenges of natural nano-based biomaterials for the future use of bone/cartilage regeneration are discussed.
•Calcination of coal sources decomposes structure of associated mineral matter.•Calcination as a pre-treatment step prior leaching increases REE recovery.•Recovery of light REEs preferentially ...increase by 50–65 percentage points.•Exceeding 600 °C causes a reduction in poor volume and REE recovery.•Evidence suggests strong correlation between REEs and phosphorus.
The pretreatment of middlings and coarse refuse material collected from a Pocahontas No.3 coal source using calcination was investigated for the potential of improving the leaching recovery of rare earth elements. Calcination at 600 °C significantly and preferentially improved light REE (LREE) recovery to values in the range of 80–90% using 1.2 M HCl. The positive effect was due to the increased pore diameter and volume as well as thermal decomposition of the minerals associated with the LREEs. Heavy REE recovery was not increased after calcination at 600 °C due to the need for higher temperatures to achieve thermal decomposition of HREE minerals. Furthermore, some HREEs were also associated with sulfide minerals (e.g., pyrite) which were transformed into low-solubility oxides (e.g., hematite) after roasting at 600 °C. Based on the leaching characteristics of the major elements (Fe, Al, Ca and Mg) and REEs along with SEM-EDX data, it was concluded that REEs in the two samples mainly occurred as phosphate minerals. In the middlings, some of the minerals were completely encapsulated by kaolinite, which was less apparent in the coarse refuse. In addition, it was found that a portion of the REEs (10–25%) in the samples were associated with the organic matter and micro-dispersed minerals in the organic matrix, was released after calcination and easily recovered using 0.1 M (NH4)2SO4 solution at pH 5. Scandium primarily occurred in mineral forms with minimum amounts associated with ion-adsorbed clays and organic association.
To detect the changes of gray matter volume (GMV) and their correlation with severity of symptom in patients with post-traumatic stress disorder (PTSD) who were defined with updated DSM-5 diagnostic ...criteria.
71 participants were assigned into PTSD group (
= 35) or trauma-exposed control (TEC) group (
= 36) with the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Voxel-based morphometry analysis was used to detect alterations in GMV in the PTSD group.
We found that the PTSD group had larger GMV in the left middle temporal gyrus (MTG) and in the right dorsal medial prefrontal cortex (dmPFC), and smaller GMV in the region of the right temporal pole (TP) than the TEC group. We also found that PTSD Checklist for DSM-5 (PCL-5) scores correlated positively with the left MTG and right dmPFC GMV, and negatively with left TP GMV. These correlations were consistent with the findings of the between-group comparisons.
GMV alterations in the MTG, dmPFC, and TP are detected in the group comparisons and correlated with symptom severity when classifying PTSD individuals according to DSM-5 diagnostic criteria within an earthquake-exposed population.
Organoids, miniature and simplified in vitro model systems that mimic the structure and function of organs, have attracted considerable interest due to their promising applications in disease ...modeling, drug screening, personalized medicine, and tissue engineering. Despite the substantial success in cultivating physiologically relevant organoids, challenges remain concerning the complexities of their assembly and the difficulties associated with data analysis. The advent of AI-Enabled Organoids, which interfaces with artificial intelligence (AI), holds the potential to revolutionize the field by offering novel insights and methodologies that can expedite the development and clinical application of organoids. This review succinctly delineates the fundamental concepts and mechanisms underlying AI-Enabled Organoids, summarizing the prospective applications on rapid screening of construction strategies, cost-effective extraction of multiscale image features, streamlined analysis of multi-omics data, and precise preclinical evaluation and application. We also explore the challenges and limitations of interfacing organoids with AI, and discuss the future direction of the field. Taken together, the AI-Enabled Organoids hold significant promise for advancing our understanding of organ development and disease progression, ultimately laying the groundwork for clinical application.
Display omitted
•AI-Enabled Organoids integrate organoid development and AI, expediting novel methodologies.•AI interfacing enables efficient organoid construction, multiscale image analysis, and precise preclinical evaluation.•Recognizing challenges in AI-Organoid integration can enhance our understanding and facilitate clinical applications.
REE recovery tests were performed on a kaolinite and the corresponding metakaolinite using pH static leaching method. Test results show that over 90% of REEs were leached from the metakaolinite ...sample at pH 0.00 and 25 °C, while less than 2% of the major constituents were simultaneously extracted. Therefore, selective leaching of REEs from the metakaolinite was achieved through pH static leaching. The leaching residue was then subjected to alkaline activation for zeolites synthesis. The effects of hydrothermal temperature and incubation period under various alkaline conditions on the synthesis of zeolites were systematically investigated. The phase compositions, textual properties, and morphology of the synthesized products were characterized. Pure zeolite A with 100% relative crystallinity was successfully synthesized at 80 °C for 6 h when using 3 M NaOH as the alkaline activator. While as the synthesis conditions became increasingly harsh, the metastable zeolite A gradually transformed into more stable sodalite, and three types of zeolites, including zeolite A, sodalite, and their mixtures, were obtained. After that, various types of zeolites were applied for Ce3+ adsorption from aqueous solutions. High purity sodalite showed a higher adsorption capacity of 53 mg/g at pH 6.0 and 25 °C as a result of the superior textual properties compared with zeolite A. The adsorption data were suitably fitted by the Langmuir isotherm and pseudo-second-order models. Findings from this study suggest that the kaolinite is a potential source for REE recovery, and the leaching residue is suitable for the synthesis of zeolites, which can be used as promising adsorbents for Ce3+ recovery.
Display omitted
•Over 90% of REEs were leached from the metakaolinite sample at pH 0.00 and 25 °C.•Residue solid after REE recovery was used for zeolites synthesis.•Zeolite A, sodalite, and their mixtures were obtained under various synthesis conditions.•High purity sodalite showed superior adsorption performance of Ce3+.
In this paper, the effect of sodium alginate (SA) on the flotation separation of molybdenite (MoS
) from chalcopyrite using kerosene as collector was systematically investigated. The results of ...single-mineral micro-flotation tests indicated that SA exhibited strong depression on chalcopyrite flotation while it imposed no impact on the floatability of molybdenite. However, in the chalcopyrite-molybdenite mixed-mineral flotation system, the presence of chalcopyrite significantly increased the depressing effect of SA on molybdenite flotation, leading to a considerable reduction in the flotation selectivity. The negative impact of chalcopyrite on the performance of SA in molybdenite flotation was eliminated by adding a certain dosage of kerosene prior to SA. A concentrate containing 53.43% of molybdenum (Mo) was obtained at 76.90% of recovery using 19 mg/L kerosene and 40 mg/L SA at pH 5.4. Zeta potential measurements indicated that the adsorption of SA on chalcopyrite surfaces was stronger than that on molybdenite surfaces, which agreed with the single-mineral flotation test results. The adsorption of SA on chalcopyrite was further confirmed to be chemisorption by Fourier-transform infrared spectroscopy (FTIR) spectra analyses. When Cu
appeared in solution, the flotation of molybdenite was strongly depressed by SA. Mechanism analyses indicated that more active sites were generated on molybdenite surfaces after the addition of Cu
, thus promoting the adsorption of SA.
Display omitted
•REEs, Cu, Zn, Ni and Co recovery from an acid mine leachate was investigated.•A product containing >98% of rare earth oxides was obtained by precipitation.•Cu and Zn concentrates ...containing 60% CuS and 58% ZnS were obtained.•Co and Ni remained in the residual solution after precipitation.•An integrated process was developed based on the experimental results.
Acid mine leachate (AML) may be a significant source of rare earth and other critical elements needed for the manufacturing of advanced electronics and renewable energy technologies. A systematic study was performed on a natural leachate collected from a coal preparation plant that treated bituminous coal containing elevated amounts of pyrite. The leachate contained 1.96 ppm total REEs, 2.52 ppm Zn, 2.15 ppm Ni, 1.22 ppm Cu, 0.77 ppm Co, and 25 ppm Mn. Sequential precipitation using simple pH control generated a pre-concentrate containing 0.82% total REEs, 1.08% Zn, 0.91% Ni, 0.50% Cu, 0.34% Co, 7.1% Mn. The pre-concentrate was further treated by re-dissolution using a 10 M HNO3 solution, which resulted in a solution pH of 1.5. The addition of oxalic acid to selectively precipitate the REEs followed by roasting of the precipitate generated a product containing >98% rare earth oxides. More than 95% of the Cu and Zn were recovered from the residual liquid using Na2S at pH 2 and 3, respectively. The CuS and ZnS contents in the corresponding concentrates were 60% and 58%, respectively. The majority of the Co and Ni remained in the residual liquid. Based on these findings, a process flowsheet was developed to recover the REEs and critical metals from AML.
PDF
