Search Results (83)

The strong uncertainty of renewable energy poses significant reliability and safety challenges for the coordinated operation of multi-integrated energy systems (MIES). To address this, a data-driven two-stage distributed robust collaborative optimization scheduling model for MIES is proposed, based on a spatiotemporal fusion conditional diffusion model (STF-CDM). First, to more accurately capture the uncertainty in renewable energy output, the model utilizes a scenario set generated by the STF-CDM model and reduced via the K-means clustering algorithm as the initial renewable energy scenarios for the distributed robust optimization set. The STF-CDM model employs a Temporal module component (TMC) unit composed of Transformer time-series modules and a Spatial module component (SMC) unit composed of CNN neural networks for feature extraction and fusion of time-series and spatial-series data. Second, a benefit allocation method based on multi-energy trading contribution rates is proposed to achieve equitable distribution of cooperative gains. Finally, to protect participant privacy and enhance computational efficiency, an alternating direction multiplier method (ADMM) coupled with parallelizable column and constraint generation (C&CG) is employed to solve the energy trading problem. The case analysis results demonstrate that the STF-CDM model proposed in this study exhibits superior performance in addressing the uncertainty of renewable energy output. Concurrently, the asymmetric Nash game mechanism and the ADMM-C&CG solution algorithm proposed in this study achieve a fair and reasonable distribution of benefits among all participants when handling energy transactions and cooperative gains. This is accomplished while ensuring system robustness, economic efficiency, and privacy. Full article

Titanium matrix composites (TMCs), characterized by low density, high strength, and excellent high-temperature mechanical properties, are becoming preferred materials for key components in aerospace engines. However, conventional casting methods for preparing TMCs often encounter issues such as composition segregation and coarse reinforcement phases, hindering their engineering application. In this study, we fabricated TiC/TC4 titanium matrix composites via hot isostatic pressing (HIP). The composites exhibited room-temperature tensile strength of 1058 ± 8 MPa, yield strength of 958 ± 12 MPa, and total elongation of 17.0 ± 0.5%. Furthermore, the TiC/TC4 composites demonstrated favorable high-temperature mechanical properties, with a tensile strength of about 500 MPa at 600 °C. Investigation into plastic deformation and fracture behavior revealed that at room temperature, tensile cracks initiated predominantly around the reinforcing TiC particles, whereas at high temperatures, cracks primarily originated within the matrix. The strengthening mechanisms of the TiC particle-reinforced TC4 composites included particle strengthening, solid solution strengthening, and load-transfer strengthening. Additionally, the precipitation of nano-acicular secondary α (αs) phases within the β phase during high-temperature tensile deformation was observed, contributing to the superior high-temperature mechanical performance of the composites. Full article

Thin-film composite nanofiltration membranes were fabricated via the interfacial polymerization method from optimized polyethersulfone (PES) mixed matrix membranes, using m-phenylenediamine and trimesoyl chloride monomers, which produced a selective polyamide layer and were used for heavy metal removal. The concentration of trimesoyl chloride (TMC) is a critical factor to govern the properties of the selective polyamide layer, which directly influences the surface morphology and selective performance of (0.5 wt%) PES-coreshell-Fe₃O₄/ZnO membranes. Morphological structure, illustrated by SEM images, elucidated the role of TMC addition. FTIR spectra validated the successful formation of the amine and acyl chloride groups. Performance studies illustrated that NF3 (made from 0.1 w/v% of TMC) showed a unique salt rejection trend (NaCl > Na₂SO₄ > MgCl₂) with an optimal salt rejection of 52.64%, 50.91%, and 12.67%. A low concentration of 0.1 w/v% of the NF3 membrane was the most optimal high-performance membrane. The adsorption rate of NF3 for Pb(II) ions in real environmental wastewater is attributed to the tailored surface chemistry of the polyamide layered thin-film/PES-coreshell-Fe₃O₄/ZnO nanocomposites of the membranes. The maximum Langmuir adsorption capacity at the optimal pH = 5 was 8.8573 mg/g at 25 °C. The fabricated adsorptive nanofiltration membranes alleviated the presence of Pb(II) ions and other competing ions present in environmental wastewater. Full article

Poly(L-lactide) (PLA) is a promising biopolymer for biomedical applications due to its biodegradability and biocompatibility; however, its brittleness restricts its use in fused deposition modeling (FDM). To overcome this limitation, flexible PLA monofilaments with enhanced mechanical performance and printability were developed. In this study, PLA was melt-blended with acetyl triethyl citrate (ATEC, 1.0–5.0 wt%) as a plasticizer and zinc phenyl phosphonate (TMC-200, 0.3 wt%) as a nucleating agent. It was found that the PLA with 3.0 wt% ATEC (PLA/A) exhibited the greatest flexibility, while the addition of TMC-200 further improved tensile strength and ductility. Specifically, the ternary blend of PLA/TMC-200/ATEC (PLA/T/A) exhibited a synergistic effect, achieving superior mechanical properties (tensile strength: 35.0 MPa, elongation at break: 232.0%, compared to 12.1% for pure PLA) and raising the degree of crystallinity (X_c) from 4.7% to 45.0%. Monofilaments (1.70 ± 0.05 mm) fabricated from PLA/T/A exhibited smooth surfaces, balanced mechanical performance, and excellent cytocompatibility (over 99% cell viability in L929 fibroblasts). Moreover, FDM-printed specimens retained enhanced mechanical and thermal performance, demonstrating material stability after processing. Shelf-life testing further confirmed the structural integrity of PLA/T/A monofilament after 8 weeks at 50 °C. Overall, PLA/T/A provides an effective strategy for producing high-performance, medical-grade PLA monofilaments with improved toughness, printability, and biocompatibility, enabling their application in biomedical 3D printing. Full article

Delayed gastric emptying (DGE) is a significant complication following pancreaticoduodenectomy, affecting 20–40% of patients and impacting hospital stay, healthcare costs, and adjuvant therapy initiation. Different gastrojejunostomy configurations have been investigated to reduce DGE rates, with conflicting results presented in the literature. This retrospective study analyzed 65 consecutive patients who underwent pylorus-preserving pancreaticoduodenectomy at Bnai-Zion Medical Center between August 2018 and December 2023. All procedures were performed by a single experienced surgeon using either antecolic (AC, n = 25) or transmesocolic (TMC, n = 40) reconstruction. DGE was classified according to International Study Group of Pancreatic Surgery criteria. The statistical analysis included logistic regression to identify risk factors. The overall DGE incidence was 23.1% (15/65 patients). The AC group demonstrated significantly higher DGE rates compared to the TMC group (40% vs. 12.5%, p = 0.01). Logistic regression analysis revealed a 5.91-fold increased risk of DGE with AC reconstruction (OR: 5.91; 95% CI: [1.44, 24.25]; p = 0.014). All severe DGE cases (grades B and C) occurred exclusively in the AC group. Hospital stay was significantly longer in DGE patients (median: 26 vs. 13 days, p < 0.001). Other variables, including age, gender, smoking, diabetes, BMI, and surgical approach, showed no significant association with DGE. In this single-surgeon study, antecolic reconstruction was associated with significantly higher rates and severities of delayed gastric emptying compared to transmesocolic reconstruction. These findings suggest that reconstruction technique represents a modifiable risk factor for DGE prevention, though larger prospective studies are needed to confirm these results. Full article

The titanium matrix composites (TMCs) fabricated via Directed Energy Deposition (DED) effectively overcome the issue of coarse columnar grains typically observed in additively manufactured titanium alloys. In this study, systematic annealing heat treatments were applied to in situ (TiB + TiC)/Ti-6Al-4V composites to refine the microstructure and tailor mechanical properties. The results reveal that the plate-like α phase in the as-deposited composites gradually transforms into an equiaxed morphology with increasing annealing temperature and holding time. Notably, when the annealing temperature exceeds 1000 °C, significant coarsening of the TiC phase is observed, while the TiB phase remains morphologically stable. Annealing promotes decomposition of acicular martensite and stress relaxation, leading to a reduction in hardness compared to the as-deposited state. However, the reticulated distribution of the TiB and TiC reinforcement phases contributes to enhanced tensile performance. Specifically, the as-deposited composite achieves a tensile strength of 1109 MPa in the XOY direction, representing a 21.6% improvement over the as-cast counterpart, while maintaining a ductility of 2.47%. These findings demonstrate that post-deposition annealing is an effective strategy to regulate microstructure and achieve a desirable balance between strength and ductility in DED-fabricated titanium matrix composites. Full article

Objectives: To investigate the impact of α-chymotrypsin treatment on sperm recovery rate and total motile sperm count (TMC) in highly viscous semen for intrauterine insemination (IUI) and in vitro fertilization (IVF), particularly in cases of severely low sperm count. Methods: High viscosity was defined by the inability to form a thread exceeding 2 cm from a semen drop after 30 min of incubation at 37 °C with repeated pipetting. Semen samples were treated with 5 mg of α-chymotrypsin for 5–10 min at 37 °C and washed using a 90% gradient solution. A total of 35 patients were included, with comparisons made to the same patients’ prior untreated samples using paired t-tests. Severely low sperm count was classified as TMC below 10 million. Results: Treatment with α-chymotrypsin significantly improved TMC (22.2 million vs. 11.6 million, p = 0.0004) and motile sperm recovery rate (38.9% vs. 16.2%, p = 0.00002). In cases of severely low sperm count, α-chymotrypsin treatment resulted in a marked increase in recovery rate (43.0% vs. 10.0%, p = 0.02) and TMC (5.89 million vs. 1.21 million, p = 0.004). Fertilization using treated samples achieved an 87.8% success rate, with a 56.4% usable blastocyst rate, comparable to standard IVF outcomes (n = 9, average age = 34.9 years). Conclusions: α-chymotrypsin treatment significantly enhances sperm recovery and TMC in highly viscous semen, demonstrating particular efficacy in patients with severely low sperm counts without affecting fertilization or blastocyst rate in IVF. Full article

Prior to the laser processing, the surface of the TiC-reinforced particles underwent a metallization process with Ni-P, with the objective of enhancing the wettability between the TiC and the Ti6Al4V, thereby ensuring enhanced wear resistance of the titanium-based composite (TMC) coatings. In this study, the chemical deposition method was utilized to synthesize three types of metallized TiC with varying phosphorus contents. The P contents of these samples were determined to be 9.12 wt.% (HP metallized TiC), 6.55 wt.% (MP metallized TiC), and 1.71 wt.% (LP metallized TiC). It was observed that the thickness of the coatings increased in a gradual manner with the decrease in P. Furthermore, the coating of the LP metallized TiC was found to possess the highest degree of crystallinity and a microcrystalline structure. The 50 wt.% TiC-Ti6Al4V composite coatings (TMC-Nickel-free, TMC-HP, TMC-MP, and TMC-LP) were produced by laser fusion deposition using untreated TiC and three metallized TiC enhancements. The findings indicate that TMC-LP exhibits cracking only during the initial processing stage. Surface metallization has been shown to enhance the wear resistance of composite coatings through several mechanisms, including increased bonding of the ceramic phase to the metal matrix and the formation of hard Ti₂Ni compounds. The wear rates of TMC-HP, TMC-MP, and TMC-LP were reduced by 22%, 43%, and 72%, respectively, in comparison to TMC-Nickel-free. Full article

The extreme environment of aerospace requires severe material properties, and in situ autogenous ZrC–NbC dual-phase reinforced titanium matrix composites have attracted much attention. In this study, TiC/Ti composites (TMC1–TMC4) with different NbC contents (0–9 wt%) were prepared and investigated in depth by various means and ANSYS simulations. The results show that the variation in NbC content significantly changes the TiC morphology from fine needles at 0 wt% to needles with a small amount of ellipsoidal grains at 3 wt%, to an ideal uniform distribution (mostly granular or nearly spherical) at 6 wt%, and to a large number of aggregates (dendritic or coarse rod-like) at 9 wt%. In terms of mechanical properties, the compressive strength and elongation firstly increased and then decreased, and reached the optimum at 6 wt% NbC, with the ultimate compressive strength as high as 1379.50 MPa, the compressive yield strength at 817.3 MPa, the compressive strain up to 38.73%, and typical ductile fracture characteristics; at 9 wt%, it transformed into a mixed fracture mode, with a decrease in performance. ZrC and NbC synergistically stabilize the microstructure, with the best synergistic effect at 6 wt% NbC, which effectively improves the overall performance and meets the requirements of aerospace applications. The simulation is highly compatible with the experiment and verifies the experiment; this helps to reveal the mechanism, provides guidance for the design of high-performance materials, and promotes the development of materials technology in the aerospace field. Full article

In aerospace applications, titanium matrix composites (TMCs) must balance high strength, thermal stability, and vibration resistance. This study investigates the microstructural evolution and multi-property correlations in single-phase ZrC-reinforced (TMC1) and dual-phase ZrC-NbC-co-reinforced (TMC2) TMCs via SEM/TEM, XRD, tensile testing, and ANSYS simulations. The in situ reaction (Ti + ZrC/NbC → TiC + Zr/Nb) and NbC-induced grain boundary pinning drive microstructural optimization in TMC2, achieving 30% higher reinforcement homogeneity and 5 μm grain refinement from 15 μm to 10 μm. TMC2’s tensile strength reaches 1210 MPa, a 15% increase over TMC1, with an elongation at a break of 4.74%, 2.2 times that of TMC1. This performance stems from synergistic Hall–Petch strengthening and nano-TiC dispersion strengthening. Modal simulations show TMC2 exhibits a first-mode natural frequency of 98.5 kHz, 1.1% higher than TMC1’s 97.4 kHz, with maximum displacement reduced by 2.3%. These improvements correlate with TMC2’s elevated elastic modulus (125 GPa vs. 110 GPa) and uniform mass/stiffness distribution. The ZrC-NbC synergy establishes a microstructural framework for the concurrent enhancement of static and dynamic properties, offering critical insights for a high-performance TMC design in extreme environments. Full article

This study examines the temperature-resolved, polymorph-specific crystallinity of poly(lactic acid), PLA, during cooling and heating at 10 °C/min, with a focus on the effects of N, N-bis(benzoyl) hexanedioic acid dihydrazide (BHAD, commercially known as TMC306) as nucleating agent and PEG 1000 as plasticizer. A semicrystalline (PLA-1) and amorphous (PLA-2) PLA grade were investigated. The study emphasizes the importance of using temperature-dependent, polymorph-specific transition enthalpies to accurately calculate crystallinities from Differential Scanning Calorimetry (DSC). Polymorphism is independently confirmed using Wide Angle X-ray Diffraction (WAXD). Pure PLA-1 reached an α′ crystallinity of 2% during cooling, which increased to 38% through cold crystallization upon heating. At BHAD concentrations of at least 0.4%, α crystallites formed instead of α′, reaching a maximum crystallinity of 38% during cooling. The addition of 10 wt% PEG to PLA-1 facilitated primary α crystallization during cooling, followed by secondary intraspherulitic α′ crystallization upon heating, resulting ultimately in a crystallinity of 34%. Adding 1 wt% BHAD into PLA-1 with 10 wt% PEG shifted the crystallization temperature upward by 40 °C and enhanced the α crystallinity to 44%, highlighting the synergistic effect of PEG and BHAD on crystallization. Full article

In order to achieve a balance between the strength and ductility of titanium matrix composites (TMCs), a spray deposition method was employed to deposit carbon nanotubes (CNTs) onto the surface of Ti foil. Subsequently, spark plasma sintering (SPS) at 850 °C and an additional 1 h heat treatment at 880 °C were utilized to fabricate two laminated composites of different composition, namely, CNTs/Ti (SPS) and in situ TiC/Ti (SPS+HT). The microstructure evolution, mechanical properties, and strengthening and fracture mechanisms of laminated composites were systematically studied. The results revealed that after sintering at 850 °C, the reaction between CNTs and the titanium matrix was limited. However, after a 1 h heat treatment at 880 °C, CNTs were completely transformed into TiC, while the titanium matrix remained α phase without undergoing phase transformation. Through rolling and annealing, TiC particles were refined to 500 nm and exhibited a flattened shape. The in situ TiC/Ti layered composite material exhibited a tensile strength (UTS) of 491.51 MPa, which was a 29.63% improvement compared to pure titanium (379.16 MPa), and significantly higher than the UTS of CNTs/Ti samples (419.65 MPa). The primary strengthening mechanism was load transfer strengthening. The elongation (EL) remained at 26.59%, slightly lower than pure titanium (29.15%) and CNTs/Ti samples (27.51%). This can be attributed to the increased connectivity of the matrix achieved through rolling, which enhanced the ability to passivate cracks and prolonged the crack propagation path. This study presents a method for preparing laminated titanium matrix composites with both strength and ductility by controlling the heat treatment process. Full article

Background: Cannabis oil titration consists of quantification of the acidic precursors tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) and their decarboxylated products, the active neutral cannabinoids delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD), and is recommended to ensure galenic preparation quality through gas and liquid chromatography coupled with mass spectrometry (GC-MS; LC-MS). Analyses by LC-MS and GC-MS involving derivatization allow for detection of acidic and neutral cannabinoids; on the contrary, GC-MS without derivatization determines only neutral cannabinoids due to high temperature-decarboxylation occurring in the injection system. However, it is not clear if decarboxylation is complete. Methods: Different GC-MS methods with (BSTFA: TMCS and pyridine; incubation at 60 °C for 25 min) or without derivatization and an LC-MS method were developed for cannabinoid quantification. The total Δ9-THC and CBD yield of recovery were compared between the methods by testing laboratory samples with known concentrations of THCA and CBDA (total Δ9-THC and CBD: 175–351–702 ng/mL) and real cannabis oil samples (n = 6). Results: The total Δ9-THC and CBD yield of recovery were determined using LC-MS and GC-MS with derivatization, but not using GC-MS without derivatization (decarboxylation conversion rate of about 50–60%). No high deviation (<10%) in the total neutral cannabinoid concentrations in real cannabis oil samples was noticed, probably due to the low content of acidic forms in the original galenic preparation. Conclusions: This study raised awareness about the potential underestimation of the total Δ9-THC and CBD content in cannabis oils when quantification is performed by GC-MS without derivatization. The advice for pharmacists is to perform complete decarboxylation to convert all acidic precursors in neutral cannabinoids. Full article

The large-scale application of aromatic polyamide (PA) thin-film composite (TFC) membranes for reverse osmosis has provided an effective way to address worldwide water scarcity. However, the water permeability and salt rejection capabilities of the PA membrane remain limited. In this work, cyclic micropores based on crown ether were introduced into the PA layer using a layer-by-layer interfacial polymerization (LbL-IP) method. After interfacial polymerization between m-phenylenediamine (MPD) and trimesoyl chloride (TMC), the di(aminobenzo)-18-crown-6 (DAB18C6) solution in methanol was poured on the membrane to react with the residual TMC. The cyclic micropores of DAB18C6 provided the membrane with rapid water transport channels and improved ion rejection due to its hydrophilicity and size sieving effect. The membranes were characterized by FTIR, XPS, SEM, and AFM. Compared to unmodified membranes, the water contact angle decreased from 54.1° to 31.6° indicating better hydrophilicity. Moreover, the crown ether-modified membrane exhibited both higher permeability and enhanced rejection performance. The permeability of the crown ether-modified membrane was more than ten times higher than unmodified membranes with a rejection above 95% for Na₂SO₄, MgSO₄, MgCl_2, and NaCl solution. These results highlight the potential of this straightforward surface grafting strategy and the modified membranes for advanced water treatment technologies, particularly in addressing seawater desalination challenges. Full article

Background Despite many studies on polymer-incorporated nanocarriers for ophthalmic drug delivery, few have thoroughly explored the relationship between coating composition and performance. This study aimed to evaluate the effects of three commonly used cationic polymers—distearoyl phosphatidylethanolamine-polyethylene glycol 1000-poly(amidoamine) (DSPE-PEG1000-PAMAM), trimethyl chitosan (TMC), and (2,3-dioleoyloxypropyl) trimethylammonium chloride (DOTAP)—on the corneal behaviors and anti-cataract efficacy of diosmetin (DIO)-loaded micelles (D-M-P, D-M-T, and D-M-D, respectively). Methods The DIO-loaded micelles were prepared using the thin-film dispersion method and incorporated with the three polymers through hydrophobic interactions and electrostatic adsorption. Structural characterization was demonstrated by TEM imaging and particle size analyzer. In vitro release behavior was detected by the dialysis method. Cell viability of D-M-P, D-M-T, and D-M-D on L929 cells was detected by CCK-8 assays, with cellular uptake performed using coumarin 6 as the fluorescence indicator. Precorneal retention behaviors of these three vesicles were observed by In Vivo Imaging System. Transcorneal permeability was determined by modified Franz diffusion method and the permeation routes of the vesicles are investigated. Selenite-induced cataract model was established. The anti-cataract effects of three different DIO-loaded micelles were evaluated by the observation of lens opacity and antioxidant enzyme activities. Eye Irritation of the DIO in different preparations was estimated using the Draize test, along with H&E staining of the corneas. Results Structural characterization of DIO-loaded micelles revealed that the vesicles were spherical, with a uniform size distribution of around 28 nm, a similar surface potential of approximately 6.0 mV, and a high DIO entrapment efficiency of about 95%. Compared to the DIO suspension, all three formulations exhibited a significant sustained-release effect. They showed no signs of irritation and demonstrated increased IC50 values in L929 cells, indicating improved biocompatibility. Cellular uptake in human lens epithelial cells (HLECs) was assessed using confocal laser scanning microscopy. C-M-T displayed the highest fluorescence signals, with a cellular internalization 3.2 times greater than that of the solution group. Both C-M-T and C-M-P enhanced vesicle retention on the corneal surface by at least 47.8% compared to the Cou-6 solution. Furthermore, TMC facilitated the paracellular transport of vesicles into the deepest layers of the cornea and delivered DIO across the cornea, with a P_app value 3.11 times and 1.49 times those of D-M-D and D-M-P, respectively. In terms of therapeutic efficacy, D-M-T demonstrated the most significant attenuation of lens opacity, along with enhanced antioxidant enzyme activities and inhibition of lipid peroxidation. Conclusion The modification of micelle vesicles with different cationic polymers significantly influences their performance in ocular drug delivery. Among the tested formulations, D-M-T stands out due to its multiple advantages, including enhanced transcorneal drug delivery, therapeutic efficacy for DIO, and safety, making it the most promising candidate for ophthalmic applications. Full article