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Molecular dynamics (MD) simulations were performed to determine the three-phase coexistence line of sI methane hydrates. The MD simulations were carried out at four different pressures (4, 10, 40, and 100 MPa) by using the direct phase coexistence method. In current simulations, water was described by either TIP4P/Ice or "optimal" point charge (OPC) models and methane was described as a simple Lennard-Jones interaction site. Lorentz–Berthelot (LB) combining rules were used to calculate the parameters of the cross interactions. For the OPC model, positive deviations from the energetic LB rule were also considered based on the solubility of methane in water. For the TIP4P/Ice water model, the obtained three phase coexistence temperatures showed good agreement with experiment data at higher pressures, which is consistent with previous predictions. For the OPC water model, simulations using the classic and the modified LB parameters both showed negative deviations to the experimental values. Our results also indicated that the deviation of the T3 prediction by the OPC model was not closely correlated with the predicted melting point of ice. At 4 MPa, the modified OPC model showed a better prediction of hydrate equilibrium temperature, even better than the prediction by TIP4P/Ice. Considering the relatively higher accuracy in biomolecular MD of the OPC model, it is suggested that this model may have a better performance in hydrate MD simulations of biomolecule-based additives. [ABSTRACT FROM AUTHOR]

Jack-up rigs are important equipment for drilling and workover in offshore oil and gas fields. Their operation site is often close to long-running jacket platforms. Spudcan penetration and extraction may have a significant influence on the lateral bearing capacity of adjacent piles of platforms. In this study, centrifuge model tests for the lateral bearing capacity of piles in sand were performed, in which model piles included an isolated pile and two spudcan-affected adjacent piles. Based on the test results of the isolated pile, the lateral soil resistance–displacement (p–y) curve for an isolated pile in sand was modified. By making a comparison of the test results of the three piles, the influence of spudcan penetration and extraction on lateral bearing capacities, bending moments, and the soil resistance of adjacent piles was analyzed. The analysis showed that the lateral bearing capacity of an adjacent pile had 8.9% reduction compared with that of an isolated pile. According to the modified p–y curve of isolated piles, a p–y curve model for a pile affected by spudcan penetration and extraction was proposed by introducing the attenuation coefficient of the sand strength. It provides an option for calculating the lateral bearing capacity of adjacent piles affected by spudcan penetration and extraction in the field of engineering. [ABSTRACT FROM AUTHOR]

Simple Summary: Forced molting refers to the systemic stress response of laying hens caused by some externally imposed artificial measures (such as starvation), resulting in production suspension, weightlessness, and molting of laying hens. After the stress is restored to normal feeding conditions, the chickens will recover their physical fitness so that the egg-laying rate can be restored to the second peak of egg production and egg quality can be improved. Previously, we thought that only genes regulate this reversible biological process at the transcriptome level, but further studies showed that environmentally induced epigenetic inheritance could also regulate this process, and there is an interspersed effect between them. Epigenetic modifications play an important role in regulating animal adaptation to external stress. To explore how DNA methylation regulates the expression levels of related genes during forced molting (FM) of laying hens, the hypothalamus and ovary tissues were analyzed at five periods using Whole-Genome Bisulfite Sequencing. The results show that methylation levels fluctuated differently in the exon, intron, 5′UTR, 3′UTR, promoter, and intergenic regions of the genome during FM. In addition, 16 differentially methylated genes (DMGs) regulating cell aging, immunity, and development were identified in the two reversible processes of starvation and redevelopment during FM. Comparing DMGs with differentially expressed genes (DEGs) obtained in the same periods, five hypermethylated DMGs (DSTYK, NKTR, SMOC1, SCAMP3, and ATOH8) that inhibited the expression of DEGs were found. Therefore, DMGs epigenetically modify the DEGs during the FM process of chickens, leading to the rapid closure and restart of their reproductive function and a re-increase in the egg-laying rate. Therefore, this study further confirmed that epigenetic modifications could regulate gene expression during FM and provides theoretical support for the subsequent optimization of FM technology. [ABSTRACT FROM AUTHOR]

Microalgae is one of the most potential materials for biofuels and dietary supplements. However, the high cost of cultivation has always restrained its commercial application. Static magnetic fields (SMF), with the advantages of low operational cost and non-toxic secondary pollution, exhibits great potential in the promotion to the microalgal growth and metabolism. In this study, the dynamic patterns on the biomass and metabolites including pigment, protein, carbohydrate, lipid and fatty acids of C. pyrenoidosa and T. obliquus under 30 mT SMF for 15 days at 24 h·d−1 were explored. Results demonstrated that SMF triggered the growth of C. pyrenoidosa and T. obliquus by 32.8% and 31.5%, respectively. SMF significantly stimulated protein synthesis by 44.3%, whereas decreased carbohydrate by 19.7% and lipid by 23.4% in C. pyrenoidosa (p < 0.05), indicating that SMF was a promising approach for inducing intracellular carbon partition to the protein synthetic pathway. The carbohydrate content exhibited a significant lower by 43.7% in T. obliquus under SMF than that of the control (p < 0.05), while no significant changes were observed in either the protein or the lipid. SMF applied for the two microalgae had negative effects on the fatty acids (MUFAs, PUFAs, and TFAs). The results indicated that SMF could not only significantly accelerate the growth of the two microalgae, but also influence their metabolites. [Display omitted] • Static magnetic fields (SMF) accelerate growth of C. pyrenoidosa and T. obliquus. • SMF increase protein content at cost of carbohydrate and lipid in C. pyrenoidosa. • SMF decrease carbohydrate content in T. obliquus. • SMF have negative effects on the MUFAs, PUFAs and TFAs in both microalgae. [ABSTRACT FROM AUTHOR]

Sugarcane crushing is a complex process with multiple factors, multiple objectives, strong coupling, large nonlinearity and uncertainty. Due to the ambiguity of the pressing mechanism and the unexplicability of data-driven, the process index of sugarcane pressing process is difficult to predict. In order to solve this problem, this paper combines deep learning with pressing mechanism, and establishes a process index prediction model of sugarcane pressing process based on physics-informed neural network (PINN). Firstly, the constitutive model of sugarcane was established based on the pressing mechanism. Combined with the porous medium control equation and numerical simulation, the sugarcane pressing mechanism model was established and verified, which provided high-quality simulation data for subsequent research. Secondly, the porous medium control equation is embedded into the PINN model as a physical law to establish a unique loss function of the sugarcane pressing process. Combining the historical data and simulation data of the workshop, a large sample data is made to train the model, and the model is compared with the common data-driven model to further illustrate the accuracy and stability of the established model. • A prediction model of sugarcane pressing process based on pressing mechanism and deep learning was proposed. • Combined with the simulation data and the historical data of the workshop, a big data sample was established. • The loss function for sugarcane pressing process was established. • The accuracy of the model for key indicators in sugarcane pressing process was proved. [ABSTRACT FROM AUTHOR]

Permeability mainly governs fluid flow through hydrate‐bearing sediments, and its theoretical models play a primary role in the efficiency prediction of gas recovery from hydrate reservoirs by using numerical simulators. Most of these numerical simulators rely on empirical or semiempirical permeability models largely due to the lack of suitable parameters that well quantify the evolution of pore structures. In this study, X‐ray computed tomography scans are conducted on methane hydrate‐bearing sands, followed by extractions of the maximal diameter and fractal dimensions for the pore space occupied by fluids. These extracted parameters, including area and volume pore‐size fractal dimensions, tortuosity fractal dimension, and the area maximal pore diameter, are further extended to develop fractal theory‐based models for predictions of the hydraulic tortuosity and the saturated water permeability in hydrate‐bearing sands. Results show that the pore space occupied by fluids within hydrate‐bearing sands is inherently fractal. The area pore‐size fractal dimension decreases but the tortuosity fractal dimension changes little with increasing hydrate saturation, and the sum of these two fractal dimensions can be used to predict the volume pore‐size fractal dimension. In addition, the area maximal pore diameter decreases with increasing hydrate saturation, and a semiempirical model is proposed. The fractal theory‐based permeability reduction model agrees well with available experimental data, and it can capture the essential physics of saturated water permeability reduction in hydrate‐bearing sediments during hydrate formation. Key Points: X‐ray computed tomography images show that the pore space occupied by fluids within hydrate‐bearing sands is inherently fractalEffects of methane hydrate on pore fractal characteristics of hydrate‐bearing sands are quantifiedA proposed fractal model for hydrate‐bearing sands depicts the saturated water permeability reduction due to hydrate formation [ABSTRACT FROM AUTHOR]

Heteroatom doping porous carbon material possess a variety of attractive functionality such as electrical properties, catalytic properties and adsorptive capability. As an important building block of DNA, adenine has following characteristics: 1. Heterocyclic structure 2. Potential interaction modes 3. Flexible structure tailor ability 4. Available from biomass. In this study, adenine-containing polyimide (API) foam has been prepared by freeze-drying, and is used as polymer precursor of nitrogen doping carbon foam (ACF). The carbon foam (PCF) prepared by adenine-free PI foam (PMDA ODA PI) is used as a comparison. The results show that the nitrogen content of ACF after carbonization at 1000 °C (ACF-1000) is as high as 4.35%, which is about twice higher than PCF-1000 (1.90%). The conductivity of ACF-1000 is 7.11 × 10−1 s cm−1, which is 38.06% larger than PCF-1000 (5.15 × 10−1 s cm−1). The electromagnetic interference shielding effectiveness (EMI SE) of ACF-1000 is 41.1 dB, which is 26.85% higher than PCF-1000 (32.4 dB). The SSE/d (defined as the SE divided by the thickness and density of the shielding material) of ACF-1000 is 13569 dB cm2/g, which is 66.41% higher than PCF-1000 (8154 dB cm2/g). This work shows that adenine is a promising nitrogen-doping building block for polymer-derived carbon materials. The introduction of adenine structure into the polymer is helpful for improving the EMI shielding performance of carbonized products. Adenine building block can effectively enhance electrical conductivity (7.11 × 10−1 s cm−1), and electromagnetic interference shielding performance (∼41.1 dB and 13569 dB cm2/g at 13 mm thickness) of polymer-derived carbon foam. Image 1 [ABSTRACT FROM AUTHOR]

In this study, a nano‐focus X‐ray computed tomography (X‐CT) is used to observe the formation of methane hydrate in sands on pore scale and to quantify hydrate saturation, pore structure parameters, and permeability of hydrate‐bearing sands. A new analytical technique is developed to improve the identification of water‐hydrate boundary. Three hydrate accumulation habits (i.e., floating, contacting, and cementing) in pore spaces are observed. When there is no methane bubble, hydrate distribution evolves from floating to contacting and then to cementing as hydrate saturation increases. In contrast, only contacting and cementing distribution patterns appear in the pores with methane bubbles. Based on the surface extraction and defect detection from 3‐D images, both the gas/water/hydrate distributions and the pore structure characteristics are investigated. The results show that the porosity, the maximal pore volume, and maximal diameter decrease as hydrates accumulate in the pores. However, the maximal pore surface, the total pore number, and the large pores (>100 voxels) number increase gradually until the hydrate saturation reaches 35%, when they turn to decrease rapidly. The pore structure parameters show detailed changes of hydrate and water on pore scale. The incompressible Navier‐Stokes equations are used to calculate absolute permeability of hydrate‐bearing sands based on X‐ray computed tomography digital images. It indicates that the microdistribution of the hydrate has a significant effect on the permeability calculation. The fluid streamlines obtained through simulation are used to track the water transport paths. Key Points: The growth of hydrate in pores with methane bubbles is different from that in pores full of waterPore structure characteristics are affected by the saturation and the distribution patterns of gas hydrateA method of calculating permeability of hydrate‐bearing sands based on X‐ray CT images is developed [ABSTRACT FROM AUTHOR]

Numerical simulation is an effective method to study the global buckling of submarine pipelines under high temperature and high pressure. The length of the pipeline model has a significant effect on the global buckling during the numerical simulation. This paper outlines the global buckling regularity of different pipes of various lengths and proposes a method to determine the pipe model length for the numerical simulation of pipe buckling by using theoretical analysis and the FEA method. A method of calculating the pipeline's critical length and upper-limit critical length is proposed based on the characteristics of the short pipe and long pipe. The numerical analysis results indicate that the global buckling amplitude of the short pipe increases with the length of the pipeline model. Therefore, the model length of a short pipeline in the numerical simulation should be equal to the actual length of the research object. In contrast, the buckling amplitude of pipes with a length greater than the critical length does not vary with the pipe length. Thus, the model length only needs to be equal to or slightly larger than the critical length. A method to determine the length of the pipe model for the numerical simulation of pipe buckling is proposed for various pipelines with different laying modes in practical engineering. [ABSTRACT FROM AUTHOR]

• VIS/NIR HSI was applied to predict microalgal biomass, carbohydrate and protein. • More samples and algorithms than previous research were used to build the HSI models. • iRF-RFR and SA-RFR models performed best in carbohydrate and protein, respectively. • The dynamic process of biomass, carbohydrate and protein was visualized based on HSI. As a new food resource approved by the National Health Commission of China, Chlorella pyrenoidosa (C. pyrenoidosa) has become commercialized in recent years with the advantages of comprehensive nutrition, especially rich in protein content. Monitoring the growth information of C. pyrenoidosa is crucial for optimizing the culture environment and increasing microalgae yield. Traditional methods for the detection of microalgae bioproducts are time-consuming and expensive. In this study, a fast visual and non-invasive method based on visible/near infrared (VIS/NIR) hyperspectral imaging (HSI) combined with chemometric methods was developed to predict the biomass, carbohydrate and protein in the cultures of C. pyrenoidosa. Twelve data preprocessing approaches, 3 feature selection methods, and 4 calibration models were used to establish and optimize the estimation models. The prediction results showed that the effects of autoscaling preprocess combined with CARS-MLR for biomass (R2 p = 0.9788, RPD = 7.6503), wavelet transform (WT) combined with iRF-RFR for carbohydrate (R2 p = 0.9935, RPD = 27.0385), and S-G preprocess combined with SA-RFR (R2 p = 0.9677, RPD = 12.9928) for protein obtained the best performances, respectively. Moreover, visualization maps of the distribution and abundance of these components in the liquid suspension of C. pyrenoidosa were obtained based on the optimal models. This study showed that HSI technology combined with chemometric methods can accurately predict the biomass, carbohydrate, and protein contents of C. pyrenoidosa in situ, which has the potential as a fast and nondestructive approach for monitoring microalgal growth information. [ABSTRACT FROM AUTHOR]

Sorting nanoparticles is of paramount importance in numerous physical, chemical, and biomedical applications. Current technologies for sorting dielectric nanoparticles have a common size limit and resolution approximately of 20 and 10 nm, respectively. It remains a grand challenge to push the limit. Herein, the new physics that deploys toroidal and multipole responses in a dielectric metasurface to exert strong and distinguishable optical forces on sub‐10 nm nanoparticles is unravelled. The electric toroidal dipole, electric dipole, and quadrupole emerge with distinct light and force patterns, which can be leveraged to promise unprecedented high‐precision manipulations, such as sorting sub‐10 nm polystyrene nanoparticles at 1 nm resolution, sorting 20 nm proteins/exsomes at 3 nm resolution, conveying, and concentrating 100 nm gold nanoparticles. Remarkably, the design can also be employed to screen out medium‐sized nanoparticles from a mixture of nanoparticles with over three sizes. This optofluidic manipulation platform opens the new way to explore intriguing optical modes for the powerful manipulation of nanoparticles with nanometer precisions and low laser powers. [ABSTRACT FROM AUTHOR]

Marine gas hydrates accumulate primarily in coarse-grained, high-permeability layers; however, highly saturated natural gas hydrates have been discovered in the fine-grained sediments of Shenhu area, South China Sea (SCS). This may be explained by key factors, such as the great abundance of foraminifera shells. In this paper, by analyzing the SCS foraminifera structure and performing hydrate formation experiments in the foraminifera shells, the contribution of foraminifera to hydrate accumulation in the SCS was investigated from a microscopic point of view. Simulations of hydrate formation were carried out in both pure SCS foraminifera shells and the host sediments. Pore structures in typical foraminifera were studied by use of micro-focus X-ray computed tomography (CT) and scanning electron microscopy (SEM). Hydrate growth and occurrence characteristics in the foraminifera shells were observed in-situ. The results showed that the presence of foraminifera significantly enhanced the effective porosity of the SCS sediments. Moreover, while the hydrates grew preferentially in the chambers of the coarse-grained foraminifera by adhering to the inner walls of the foraminifera shells, no apparent hydrate accumulation was observed in the fine-grained or argillaceous matrix. These findings provide a basis for further studies on the accumulation mechanism of hydrates and physical properties of hydrate reservoir in the South China Sea. [ABSTRACT FROM AUTHOR]

Permeability governs the fluid flow of hydrate-bearing sediment and affects the efficiency of natural gas production from hydrate reservoirs. The permeability in hydrate-bearings sediments is estimated empirically and appears to vary widely for sediments. This study focused on the sandy hydrate-bearing sediments and intended to elucidate the evolution of effective permeability by the mean of pore network modeling. A hydrate kinetics theory-based pore network model (KT-PNM) has been developed, in which the simulation of hydrate formation in porous media is implemented by employing two sub-processes, i.e., hydrate nucleation and hydrate growth. This KT-PNM has been applied to simulate hydrate formation in different pore networks. The permeability reduction exponent (N) for sandy hydrate-bearing sediments is determined to fall in the range of 3–4 based on the simulations of seven sandy samples. An empirical equation used for predicting the effective permeability in sandy hydrate-bearing sediments has been further proposed. The developed model and simulations are hoped to provide valuable insights of pore-space effects on hydrate into permeability prediction for studying the fluid seepage in hydrate-bearing sediments and facilitate the numerical simulation of gas production from the hydrate reservoirs. [ABSTRACT FROM AUTHOR]

Methylene blue-loaded silica (silica-MB) was coated by a shell of polyethylene glycol (PEG), citrate ions and octacalcium phosphate (OCP) through a facile sol–gel method. The influences of molecular weight of PEG, addition amount of PEG and citric acid on the phase, morphology and chemical composition of samples were characterized by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. Compared with that of silica-MB, the sustained-release behavior of MB from silica-MB@OCP was sensitive to the shell structure and the pH value of culture solution. At each time interval, the ratio of absorbance of MB monomers over that of MB dimers released from silica-MB@OCP was higher than that from silica-MB, indicating that the significant influence of interaction density among the network of PEG, citrate ions and OCP on the release behavior of MB. Silica-MB and silica-MB@OCP were degraded when MB molecules diffused to the culture solution from solid silica matrix, which would shed light on the self-destruction investigation of drug/drug carrier systems in the biological system. [ABSTRACT FROM AUTHOR]

An in situ hydrothermal crystallization method with presence of glutamic acid, urea and yttrium ions was employed to fabricate hexagonal hydroxyapatite (HAp, Ca 5 (PO 4 ) 3 (OH)) tubes with length of 200 nm–1 μm. Firstly, yttrium ion-doped HAp (Y-HAp, Ca 5 − x Y x (PO 4 ) 3 (OH)) was synthesized after hydrolysis of urea and HPO 4 2 − ions at 100 °C with a dwell time of 24 h. The shift of X-ray diffraction peaks of HAp to high angle was caused the substitution of Ca 2 + ions by small-sized Y 3 + ions. At 160 °C, further hydrolysis reactions of urea and HPO 4 2 − ions resulted in the generation of ample OH − and PO 4 3 − ions, which provided a high chemical potential for the dissolution of Y-HAp and recrystallization of HAp and YPO 4 . Finally, HAp tubes were formed in situ on Y-HAp according to the Kirkendall effect as a result of the difference of diffusion rate of cations (Ca 2 + ions, outward and slow) and anions (OH − and PO 4 3 − ions, inward and fast). The formation process of HAp tube was simulated by the encapsulation of fluorescein molecules in precipitates. Photoluminescence properties were enhanced for HAp tubes with thick and dense walls. This novel tubular material could find wide applications as carriers of drugs, dyes and catalysts. [ABSTRACT FROM AUTHOR]

A facile hydrothermal method was employed to synthesize submillimeter-long octacalcium phosphate (OCP) and hydroxyapatite (HAp) crystals as drug carriers. After hydrolysis reaction of urea, calcium phosphate fibers grew preferentially along c-axis due to modulation of crystallization by glutamic acid. With increasing addition of urea, OCP and HAp precipitated with decreased values of crystallite size and aspect ratio. It was found that the conversion of OCP to HAp was completed after hydrothermal treatment at 160 °C for 6 h. The formation of fibrous crystals and adsorption of water-insoluble drugs were accomplished in one-step synthesis process with presence of ibuprofen molecules. The sustained-release behavior of ibuprofen could be described by a Higuchi model. HAp and OCP fibers might be simultaneously used for high-performance reinforcements to improve mechanical properties of composite materials and sustained-release drug carriers to cure postoperative infection of bone replacement. [ABSTRACT FROM AUTHOR]

Abstract: The formations of non-metabolic stones, bones and teeth were seriously related to the morphology, size and surface reactivity of dicalcium phosphate dihydrate (DCPD). Herein, a facile biomimetic mineralization method with presence of glutamic acid and arginine was employed to fabricate DCPD with well-defined morphology and adjustable crystallite size. In reaction solution containing more arginine, crystallization of DCPD occurred with faster rate of nucleation and higher density of stacked layers due to the generation of more OH− ions after hydrolysis of arginine at 37°C. With addition of fluorescein or acetone, the consumption of OH− ions or desolvation reaction of Ca2+ ions was modulated, which resulted in the fabrication of DCPD with adjustable crystallite sizes and densities of stacked layers. In comparison with fluorescein-loading DCPD, dicalcium phosphate anhydrate was prepared with enhanced photoluminescence properties due to the reduction of self-quenching effect and regular arrangement of encapsulated fluorescein molecules. With addition of more acetone, DCPD was prepared with smaller crystallite size via antisolvent crystallization. The simulated process with addition of amino acids under 37°C would shed light on the dynamic process of biomineralization for calcium phosphate compounds. [Copyright &y& Elsevier]

Abstract: Micrometer-sized powders with small crystallite sizes, high dispersion, and high copper contents, like Cu and/or Cu2O assembled on core particles would find potential applications in fields of catalysts, transparent conducting films and plasmonic-based technologies. Novel hydroxyapatite (HA)/copper assemblies were synthesized via a facile glucose reduction route. During hydrothermal treatment, copper ions were firstly released after dissolution of copper-modified HA, then reduced by glucose and finally assembled as shell on HA aggregates. After 12 h, cuprous oxide grew with truncated-octahedron morphology. When the reduction time was prolonged to 24 and 36 h, Cu phase was formed in situ via glucose reduction of Cu2O. Interestingly, HA/copper assemblies with well-defined morphologies were prepared under different reaction conditions. With presence of more Na2CO3, the reduction of copper ion occurred at a fast rate, which resulted in formation of spherical assemblies. Contrastingly, reduction reaction hardly occurred without Na2CO3 addition and assemblies with irregular morphology were prepared. Additionally, copper fibers with length of millimeters were prepared without Na3Cit addition. The UV–Vis absorbance peak of assemblies showed a blue or red shift due to the effect of crystalline size and/or hollowing process. [Copyright &y& Elsevier]

Organic dye of methylene blue (MB) was encapsulated in core-shell structured hydroxyapatite/silica particles (HAp/silica-MB) through a modified Stöber method with the addition of polyvinylpyrrolidone molecules. It was found that MB molecules were released from HAp/silica-MB at a slower rate than those from silica-MB in deionized water. In phosphate buffered saline (pH: 7.2-7.4) and acidic solutions (pH: 1.5-1.6), the penetration of ions in the interface influenced the interaction between HAp and MB molecules, which resulted in the rapid release of MB molecules from HAp/silica-MB. From the UV-Vis absorbance spectra, one could see that MB molecules in HAp/silica-MB were weakly aggregated in comparison with those in silica-MB. For HAp/silica-MB, enhanced luminescence properties were observed in the photoluminescence spectra and dual luminescence with two emission peaks were caused by the presence of monomers and dimers. Contrarily, no photoluminescence emission was detected for samples of free MB and silica-MB under the same excitation condition because of the self-quenching effect. It was the adsorption of MB molecules on HAp that had resulted in the enlargement of intramolecular distance and the reduction of self-quenching effect. These hybrid particles with enhanced luminescent properties might find wide applications in the field of bioanalysis, bioseparation, and biomedical imaging. [ABSTRACT FROM AUTHOR]

Low‐cost and environment‐friendly MgO was used as a new gelling and consolidating agent to fabricate porous Al2O3‐based ceramics via a gel casting routine. Effects of 800°C calcined additions of MgO (.5, 1.0, 1.5, and 2.0 wt%, respectively) on open porosity (OP), pore size distribution, gas flux, and microstructure of the porous ceramics were investigated deliberately. The experimental results showed that 800°C calcined MgO exhibits excellent gelling and consolidating performance at 80°C, mainly owing to the hydration reaction between MgO and H2O and thus results in high‐quality porous Al2O3‐based ceramics without deformation and cracking. The Al2O3–water suspensions with different MgO additions have good flowability at room temperature. Moreover, water absorption, open porosity, and gas flux of the as‐prepared porous ceramics increase remarkably with rising of MgO addition. Furthermore, MgO addition significantly suppresses the abnormal growth of Al2O3 grains, and thus the microstructure of the porous Al2O3‐based ceramics becomes more uniform. This technique of gel casting using MgO as a new gelling and consolidating agent offers an alternative routine for a large‐scale production of porous ceramics. [ABSTRACT FROM AUTHOR]

This study employed a co-precipitation method to synthesize copper-modified hydroxyapatite (HA) powders, where Cu2+ ions had entered the structure of HA and occupied Ca(1) sites in the columns parallel to the c-axis. Through a hydrothermal treatment, hollow HA/copper (Cu2O and/or Cu) microspheres with core–shell structures were prepared in solutions containing glucose, sodium carbonate and sodium citrate. When prolonging the reduction time, Cu2+ ions dissolved from copper-modified HA were reduced by glucose initially to Cu+ ions and then to Cu atoms, which would precipitate as copper on the surface of HA. The formation of microspheres with hollow structures was explained by the Kirkendall effect which states that diffusion behaviors of ions were different for HA and copper precipitations. Hybrid HA/copper powders might find their applications in gas sensors, catalysts, electrodes and so on. [ABSTRACT FROM PUBLISHER]

LiFePO/C composite cathode material is prepared by ball milling with the assistance of EDTA chelation with using water as the media of ball mill procedure. FePO and LiOH are used as starting materials; a certain amount of glucose is used as carbon sources and reduction agent. The structure and morphology of the composite are characterized by X-ray diffraction and scanning electron microscopy. Cyclic voltammetry, AC impedance measurements, and galvanostatic charge-discharge and cycling performances are used to characterize its electrochemical properties. The results indicate that the performances of composites prepared by chelation-assisted method are much better than common ball milling method which using alcohol or acetone as the media of ball mill procedure. The stable discharge capacity of the prepared composite is 150 and 105 mAh g at 1 and 10 C rate, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Large-sized hydroxyapatite (HA) whiskers with length of 50–100μm and width of 0.5μm were synthesized by a facile hydrothermal method. Dilute reaction solutions containing glutamic acid were used in order to achieve low degree of supersaturation with respective to HA precipitation. The supersaturation values at different hydrothermal temperatures were calculated theoretically from ion concentrations with considerations of all association–dissociation balances between various ions. Experimentally, it was found that HA whiskers with smaller sizes were obtained when raising the additive amount of NaOH or glutamic acid. The regulation mechanism of crystal growth along c-axis was proposed according to the degree of supersaturation, the adsorption/desorption behaviors of glutamate occurred on HA’s (100) and (001) planes, as well as the concentration effect of glutamate’s selective adsorption. [Copyright &y& Elsevier]

Abstract: Reversible aggregation–redispersion transition of colloidal particles is of considerable importance in colloidal science and various industrial fields. In the present study, stimuli-responsive hybrid hydroxyapatite (HA) particles were prepared with redispersible ability in aqueous solutions even after separation from the “as synthesized” state and subsequent dry heat treatment. We firstly modified HA particles with sodium oleate as chelating agent, then introduced bromoalkyl functional groups through an addition reaction of unsaturated oleate molecule with bromine, and finally grafted polymer brushes of polystyrene-co-4-vinylpyridine onto HA. It was the pH-sensitive polymer shell that had rendered HA particles the redispersible ability, which was attributed to the protonation of the pyridine blocks in acidic solutions. The reversible dispersion–aggregation transition of HA could be controlled by alternating the pH value of aqueous solution. Protonated pyridine blocks had provided enough electrostatic and steric repulsions for colloidal HA to avoid effective collision. [Copyright &y& Elsevier]

Abstract: Olivine composites LiFe1−x Mn x PO4/C (x =0, 0.05, 0.1) were prepared by chelation assisted mechanochemical activation method using C2H2O4 as the chelating reagent. The structures of the prepared composites were characterized by X-ray diffraction (XRD). Cyclic voltammetry, ac impedance spectroscopy, galvanostatic charge/discharge performances were studied at room temperature. The discharge capacity of LiFe0.95Mn0.05PO4 was 155.6mAhg−1 and 102.9mAhg−1 at 1C and 10C rate, respectively. The results indicated Mn2+-doping in LiFePO4 could effectively enhance the electrochemical performances of this olivine compound especially at high charge/discharge rate. In addition, charge/discharge method was also used to characterize the low temperature properties of the different samples. The results showed that the lower the operation temperature was, the poorer the performances were. Furthermore, ac impedance measurement was used to understand the factors of the poor performances at low temperature. [ABSTRACT FROM AUTHOR]

Abstract: Colloidal hydroxyapatite (HA) with long-term stability was essential for its potential applications in the biomedical field. Polymer/surfactant pair of poly(ethylene oxide) and sodium oleate were used for surface modification of spherical HA particles with nanoscale sizes. Suspensions with different solid loadings were prepared and observed through sedimentation studies with purpose of investigating the effect of surface modification on the colloidal stability. It was found that after decorated with polymer/surfactant pair, colloidal HA particles were obtained with satisfied dispersion stability and less conglomeration due to the existence of both electrostatic repulsion and steric hindrance effects. Based on the investigation of surface chemistry of modified HA powders, a schematic illustration about multilayered surface structures with polymer/surfactant pair was put forward and might favor to prepare a wide range of dispersible particles in aqueous solutions. [Copyright &y& Elsevier]

Abstract: Ca(OH) 2 and H3PO4 were used to synthesize nano-sized hydroxyapatite. In the process of acid–base reaction, citric acid or sodium citrate was added to influence the crystallinity of hydroxyapatite. Formation of Ca-citrate complex resulted in variations of ionic concentrations and ionic activity products for solutions with different citrate additions. The degree of supersaturate was found higher for solutions with less citric acid or more sodium citrate addition. Consequently, hydroxyapatite particles with smaller size were gained. These crystalline behaviors were investigated and explained by mechanism of crystal nucleation and growth in solutions. [Copyright &y& Elsevier]

Abstract: Calcium phosphate powders with nano-sized crystallinity were synthesized by neutralization using calcium hydroxide and orthophosphoric acid with the assistance of citric acid. The influence of processing parameters, such as free or additive citric acid, synthetic temperature and ripening time, on the crystallinity of hydroxyapatite were investigated. The results of X-ray diffraction and microstructure observations showed that the crystallinity and morphology of nano-sized hydroxyapatite particles were influenced by the presence or absence of citric acid. It was found that the crystallinities and crystallite sizes of hydroxyapatite powders prepared with the additive citric acid increased with increasing synthetic temperature and ripening time. Especially, the crystallinities of (h k 0) planes were raised and more homogeneously grown particles were obtained with increasing synthetic temperature. [Copyright &y& Elsevier]

Global buckling of a submarine pipeline during high pressure/high temperature (HP/HT) operation results in a loss of pipeline stability that is similar to a bar in compression; this phenomenon constitutes one of the key factors affecting pipeline integrity and design. To intuitively study the buckling response, a test system was designed that can account for thermal loading and pipe-soil interactions, and this system was used to perform a series of small-scale model tests on the lateral buckling of submarine pipelines with different initial imperfections. Based on the hat-shaped buckling profiles of the test pipelines, a new buckling mode called "hat-shaped buckling" was proposed. In an attempt to study the conditions under which the pipeline exhibits this hat-shaped buckling mode, the changing law of the buckling mode was investigated through finite element analyses of pipelines with different parameters, including the length of the pipeline and the amplitude and wavelength of the initial imperfection. Subsequently, an analytical solution for calculating the buckling amplitude of a pipeline with a hat-shaped buckling profile was proposed. The theoretical solution was compared to the experimental data, which verified the feasibility of the model in calculating pipeline buckling deformation. The experimental data, the buckling mode based on these data and the corresponding analytical model discussed herein may provide a reference for future experimental studies of pipeline buckling. • A series of model tests were performed on the lateral buckling of submarine pipelines by utilizing a designed test system. • A new buckling mode named "hat-shaped" buckling was proposed on the basis of the test results; the cause and influencing factors of this "hat-shaped" buckling were studied. • An analytical solution for pipelines with hat-shaped buckling was proposed. [ABSTRACT FROM AUTHOR]

CH4/CO2 replacement is of great significance for the exploitation of natural gas hydrate resources and CO2 storage. The feasibility of this method relies on our understanding of the CH4/CO2 replacement efficiency and mechanism. In this study, CH4/CO2 replacement experiments were carried out to study the distribution characteristics of CH4 and CO2 in hydrate-bearing sediments during and after replacement. Similar to previously reported data, our experiments also implied that the CH4/CO2 replacement process could be divided into two stages: fast reaction and slow reaction, representing CH4/CO2 replacement in the hydrate-gas interface and bidirectional CH4/CO2 diffusion caused replacement, respectively. After replacement, the CO2 content gradually decreased, and the methane content gradually increased with the increase of sediment depth. Higher replacement percentage can be achieved with higher replacement temperature and lower initial saturation of methane hydrate. Based on the calculation of CO2 consumption amounts, it was found that the replacement mainly took place in the fast reaction stage while the formation of CO2 hydrate by gaseous CO2 and water almost runs through the whole experimental process. Thus, the pore scale CH4/CO2 replacement process in sediments can be summarized in the following steps: CO2 injection, CO2 diffusing into sedimentary layer, occurrence of CH4/CO2 replacement and CO2 hydrate formation, wrapping of methane hydrate by mixed CH4-CO2 hydrate, continuous CO2 hydrate formation, and almost stagnant CH4/CO2 replacement. [ABSTRACT FROM AUTHOR]

Permeability anisotropy plays a crucial role in accurately predicting fluid productions during hydrate exploitation. However, the mechanisms governing permeability anisotropy have yet to be fully elucidated. This study conducted experiments on methane hydrate formation/dissociation in both unsaturated and saturated quartz sands, followed by X-ray computed tomography scanning and pore structure characterizations. Fractal parameters, encompassing fractal dimension, tortuosity fractal dimension, and maximum pore diameter, were employed to characterize the evolution of pore structure and changes in permeability anisotropy. Results show that the fractal dimension and maximum pore diameter decreased, while the tortuosity fractal dimension increased with the increase of hydrate saturation. Larger maximum pore diameter and smaller tortuosity fractal dimension in the horizontal direction become more pronounced with increasing hydrate saturation, resulting in heightened permeability anisotropy (k h /k v). The permeability anisotropy increases from 1.77 to 3.20 with hydrate saturation increasing from 0 to 0.38 in unsaturated sands, and from 1.47 to 4.70 with hydrate saturation increasing from 0 to 0.49 in saturated sands. Gas and water relative permeability anisotropy also amplifies with increasing hydrate saturation. Extrapolating to field tests, the findings suggest that horizontal wells present a more favorable option for gas production, especially in reservoirs with high hydrate saturation. • A quantitative analysis of the effects of pore structure on permeability anisotropy is presented. • Smaller tortuosity fractal dimension and larger pore diameter in the horizontal direction significantly contribute to permeability anisotropy. • Hydrate dissociation decreases gas and water relative permeability anisotropy. [ABSTRACT FROM AUTHOR]

A novel electrolyte additive, 3, 3, 3‐trifluoropropylmethyldimethoxysilane (TFPMDS), is first proposed to modify both the cathode and the anode of lithium‐ion batteries at the same time. Charging/discharging tests demonstrate that the electrolyte with 1 wt% TFPMDS not only greatly improves the capacity retention of LiNi0.5Mn1.5O4 (LNMO)//Li cell (29.6%→90.8%) and graphite//Li cell (68.1%→98.3%), but also successfully ensures the long‐term cycle stability of LNMO//graphite pouch cell at 4.9 V. Further electrochemical measurements combining with spectroscopic characterization and theoretical calculations indicate that TFPMDS additive displays three principal functions: 1) Be preferentially oxidized to build a robust cathode electrolyte interphase (CEI) enriched in F/Si species with F‐rich nature of strong oxidation‐resistance. 2) Be able to scavenge the hazardous HF, F−, and H+ through its strong binding with these species and thus to protect LNMO at high‐voltage. 3) Be preferentially adsorbed on the graphite surface to form a "framework", and to co‐construct an elastic solid electrolyte interphase (SEI) after the reduction of ethylene carbonate. Importantly, the Si─O group within TFPMDS is especially important for constructing a "molecular bridge" at the CEI/SEI interphase coupling the inorganic and organic species to improve its compatibility, stability, and elasticity. [ABSTRACT FROM AUTHOR]

Abstract: Bioactive hydroxyapatite (HA) powders with nano-crystallinity were prepared by an economic way, i.e. the neutralized route, during which a supersaturated suspension of lime chelated with citric acid was titrated by orthophosphoric acid diluted with deionized water or ethanol. The crystal behaviors of HA powders were characterized by X-ray diffraction and Fourier transform infrared spectra. It was found that uncalcined powders were amorphous calcium phosphate, while the crystallinity increased significantly after calcined at 800 °C and their crystal sizes synthesized with aqueous and ethanol solutions were determined as 54.8 and 85.4 nm, respectively. The inhibition of crystal growth was attributed to the chelating reagent, resulting in the B-substituting CO3 2− ions to PO4 3− groups and causing a-axis shortened and c-axis lengthened in the crystal cell. [Copyright &y& Elsevier]

• This paper outlines the significant effects of the pipe-soil interactions on pipeline walking. • A set of large-scale model tests are conducted on the axial soil resistances of pipelines placed on Bohai sand. • Based on the test results and the influence mechanisms of the pipe-soil interactions on pipeline walking, a bi-linear pipe-soil interaction model for pipelines placed on sandy soils is proposed. • This paper presents an alternative method for the identification of pipe-soil interaction during pipeline-walking analysis for a certain site-specific soil. Pipeline walking induced by heat-up and cool-down cyclic loadings during shutdown and restart cycles is a challenge in the design of relatively short pipelines exposed on seabeds. A major source of uncertainty in the analysis of pipeline walking is the pipe-soil response, which has a significant influence on pipeline walking. To investigate the pipe-soil response during pipeline walking, a set of large-scale model tests are conducted on Bohai sand, and they involve axially moving pipelines with different speeds and cycles. Based on these test results, bi-linear pipe-soil interaction models with normalization of the pipe weight and diameter are proposed for Bohai Bay sand. Subsequently, a comparison of the model test data to existing pipe-soil interaction models is performed, and the existing pipe-soil interaction models are calibrated with site-specific soil properties of Bohai Bay sand. Finally, the application of the site-specific pipe-soil interaction models for a pipeline-walking analysis of pipeline placed on Bohai Bay sand is performed with the finite element method to study how pipeline walking is influenced by these pipe-soil interaction models. Combined with the influence mechanisms, a design model is proposed that considers the potential risks of pipeline walking in pipeline design to reduce costs without compromising reliability. [ABSTRACT FROM AUTHOR]

Initial imperfections (out of straightness) constitute one of the key parameters impacting lateral buckling of pipelines as they influence both pre-buckling assessment and pipeline integrity assessment during the post-buckling stage. When adjacent imperfections exist in a submarine pipeline, the influence regularity of initial imperfections on the global buckling of pipelines will become more complicated. An elastic-plastic 3D-Explicit numerical method is proposed to investigate the global lateral buckling of pipelines with single and double imperfections. Then, an investigation is conducted on the influences of the spacing, relative direction and relative size of double imperfections on the global buckling characteristics, such as the critical temperature rise, the buckling deformation amplitude and the buckling mode. Based on the limit state criteria of global buckling pipelines in DNVGL-RP-F110, the structural integrity of pipeline with different buckling modes is assessment. The results show that pipeline failure has a certain correlation with its buckling mode type. For pipelines with the same buckling mode type, the pipeline failure parameter is approximately linearly associated with the double-imperfection spacing. • An elastic-plastic 3D-Explicit numerical method is proposed, which considers the plastic characteristics of pipelines post buckling. • Types of buckling modes for double-imperfection pipelines are summarized. And the relationship between the failure parameter of pipelines and their buckling mode types is illustrated. • Influence mechanism of the larger imperfection among double imperfections on the buckling of the smaller imperfection is illustrated. [ABSTRACT FROM AUTHOR]

The potential of polyimide as a matrix of three dimensional frameworks was demonstrated and discussed. Hydrophilic cellulose nanocrystals (CNC), a renewable nanofiller, and copper nanoparticles were anchored into the polyimide frameworks, based on characteristics of two-step procedure of polyimides. The influences of the addition of CNC on properties and morphological evolution of the porous framework were studied. Furthermore, an "incomplete thermal imidization" strategy was utilized to reserve carboxylate groups of the precursor of the polyimide, enabling the constructed framework precursor to further capture Cu2+ even at low concentration (80 ppm). Then related metal nanoparticles can form in situ on the porous framework through a facile thermal imidization reaction, which is called a "secondary-assembly" strategy here. The presented strategy may be further applied to assembly more functional nanoparticles, and build a platform material with manifold application potential such as oil clean-up, high performance catalyst and removal and reuse of heavy metals. Image 1 • Polyimide was used to fabricate multifunctional porous frameworks. • The percentage of CNC can regulate microscopic morphology of the frameworks. • A "secondary-assembly" strategy was presented to assemble nanoparticles on porous polyimide frameworks. • A method of reuse and removal for heavy metal ions was demonstrated. [ABSTRACT FROM AUTHOR]

Studying the pore-scale characteristics of gas hydrate-bearing sediments (GHBS) is very important for a deep understanding of (i) how fluid flows therein and (ii) the corresponding gas production. Micro X-ray computed tomography (X-CT) and low-field nuclear magnetic resonance (NMR) are often used independently to characterize the pore structure of GHBS. Here, we present a new testing assembly that combines X-CT scans and low-field NMR tests to determine the pore-scale characteristics of GHBS in situ. The main parts of the testing assembly are a removable core holder made of polyether ether ketone, an X-CT system, and a low-field NMR system. The core holder allows for independent pressure control for the formation/dissociation of gas hydrates, which is xenon hydrate here. X-CT scans and low-field NMR tests are conducted successively to obtain not only the hydrate pore-scale behavior but also the transverse relaxation time distributions of GHBS. Correlation analysis between the pore size distributions and the transverse relaxation time curves gives the transverse surface relaxivity of xenon hydrate-bearing sediments during hydrate dissociation. The results show that the hydrate pore occurs as a mixture of grain-coating, cementing, pore-filling, and patchy clusters in a gas-dissolved solution. The peak pore size at the maximum frequency ratio increases with decreasing hydrate saturation. In addition, the transverse surface relaxivity dependence on hydrate pore occurrences is in the range of 67.1–129.3 µm/s when the hydrate saturation is lower than 0.4. The combination measurements for GHBS have a promising potential in understanding the structure evaluation of pore space during gas recovery. [ABSTRACT FROM AUTHOR]

A pipeline is prone to axial movement, called pipeline walking, under heat-up and cooldown cycles. The build-up of axial force along the pipeline can result in the phenomenon referred to as lateral buckling. Walking and lateral buckling can both influence pipeline movement performance and threaten the safety of pipeline systems. The numerical simulation method is adopted to study the pipeline movement laws under walking and buckling interactions. Walking and buckling interactions are classified into three types for different forms of seabed slopes, and corresponding mitigation methods are proposed. The effects of buckling number, route bend, sleeper spacing, and anchor position on the lateral displacement amplitude, axial displacement, and effective axial force (EAF) of the pipeline are analyzed. Criteria for the mitigation methods are proposed based on parameters such as the pipeline end expansion, buckling failure parameter, maximum anchor force, and minimum compressive EAF. The results show that the anchor position has a great influence on the intertransformation of pipeline buckling and walking. The difference in anchor force can reach 51.1% considering different anchor positions. [ABSTRACT FROM AUTHOR]

The clarification of the pipe–soil interaction mechanism is a critical link in the design of the in-situ stability of shallow embedded pipes in subsea areas, and the in-situ embedment of pipelines is an important parameter in the pipe-soil interaction mechanism. A large-scale plane strain model test was performed for a shallow embedded pipeline with horizontal cyclic motion in sand. Additionally, a numerical analysis model that is applicable to multicycle submarine pipe–soil interactions in sand was constructed, which can consider the dynamic change in the pore ratio of sand during the motion of a shallow buried pipeline. The development law of dynamic embedment and factors influencing the pipeline after multiple horizontal cycles were studied. A method for calculating the dynamic embedment of pipelines in sandy soil was proposed. The results reveal that horizontal cyclic movement of the pipe in sandy soil increases the embedment depth, and dynamic embedment rises by 1.09–11.78 times depending on the initial state of the pipeline. Furthermore, a soil berm rises on both sides of the pipe following cycling, and the sand around the pipe is sheared and shrunken, causing a large increase in soil resistance during the horizontal movement of the shallow embedded pipe. • This paper outlines the change law of dynamic embedment during the cyclic movement of shallow embedded pipelines in sand. • Factors influencing the dynamic embedment of pipelines are analysed through a numerical model. • The empirical formulas for determining the dynamic embedment of pipelines in sand is provided based on numerical results. [ABSTRACT FROM AUTHOR]

The spectacular observational phenomena lying in blazars can be well explained and described by the relativistic beaming effect that the emission in the jet is highly boosted along the line of sight to observers. Aiming to reveal the intrinsic emission core dominance in γ-ray loud blazars, we collect a large sample including 226 blazars with available superluminal motion data and radio core-dominance parameters at 5 GHz, and calculate a crucial parameter, R ⊥, defined as the ratio of the luminosity in the jet to the unbeamed luminosity when the viewing angle comes up to 90°. R ⊥ is a better parameter than the well-known core-dominance parameter, R , to reveal more intrinsic physical properties behind the prominent observational characteristics within blazars. We primarily ascertain the updated median value of R ⊥ = 0.032 at 5 GHz, illustrating around 97 per cent of the total radio emission are dominated by the jets in γ-ray loud blazars. We also make further discussion on the physical difference in BL Lacertae objects and flat-spectrum radio quasars. [ABSTRACT FROM AUTHOR]

Aiming to answer an interesting question on why some radio sources can be detected by Fermi-LAT but others cannot, we compare several parameters of Fermi-detected Fanaroff-Riley radio galaxies (FFRs) and non-Fermi-detected sources (NFFRs), including the optical absolute magnitude, 1.4 GHz radio luminosity, radio loudness, core dominance parameter, Doppler factor, and the mass of the central black hole. Significant differences are ascertained within these parameters between FFRs and NFFRs. Our findings suggest that FFRs are jet-dominant while NFFRs are disk-dominant sources, and NFFRs have a weaker beaming effect. Additionally, we predict the observed γ -ray flux for NFFRs, establishing that the reason why some NFFRs are not detectable arises from their γ -ray flux being below the sensitivity detection threshold of Fermi. We also discuss two sub-types of Fanaroff-Riley galaxies, namely FR I and FR II sources. We first propose a "changing-look" phenomenon in these radio sources and also investigate why FR IIs seem to be exclusive in γ -ray emission. [ABSTRACT FROM AUTHOR]

Metal-based nanozymes with exceptional physicochemical property and intrinsic enzymatic properties have been widely used in industrial, medical, and diagnostic fields. However, low substrate affinity results in unsatisfying catalytic kinetic and instability in complicated conditions, which significantly decreases their sensitivity and reliability. Herein, an amorphous hollow manganese silicate nanosphere (defined as AHMS) has been successfully synthesized via a facile one-step hydrothermal method and utilized in the archetype for colorimetric detection of biothiols with high sensitivity and high reliability. The experimental data demonstrates that ultrafast affinity of the substrate contributes to enhanced sensitivity with outstanding catalytic kinetic features (Km = 27.1 μM) and low limit of detection (LODGSH = 20 nM). The designed sensor demonstrates a reliable applicability for analysis of biological liquids (fetal calf serum and Staphylococcus aureus) and design of visual logic gates. Therefore, AHMS provides a promising strategy for ultrasensitive and high-reliable biosensing. [ABSTRACT FROM AUTHOR]

For patients with inoperable locally advanced vulvar cancer (LAVC), concurrent chemoradiation is the standard of care. Given proximity to nearby critical structures, many patients with LAVC are unable to undergo surgical resection, increasing the risk of local failure in these patients. Dose-escalation of external beam radiotherapy (EBRT) has been studied as a significant means by which local control (LC) outcomes might be improved, however, sparing of critical organs at risk (OARs) remains a clinical challenge. Brachytherapy provides an avenue by which highly conformal dose-escalation can be achieved in patients with LAVC. Here we describe various brachytherapy techniques utilized in a case series of patients with LAVC treated at our institution. After upfront chemoradiation to the pelvis, vulva and at-risk regional nodal basins, eligible patients with LAVC were evaluated by EUA for disease mapping prior to initiation of chemoradiation. PET/CT and/or MRI was performed for staging, and colposcopy was performed to exclude synchronous cervical or vaginal malignancies. Via multidisciplinary consensus, patients were deemed to be poor surgical candidates. Procedures were performed in a hospital operating room setting under general anesthesia. The brachytherapy procedure for each patient was individualized to ensure target coverage and sparing of adjacent normal structures. Post-operatively patients underwent CT simulation to ensure appropriate needle position and guide adjustments as deemed optimal. Target volumes and OARs were then contoured, followed by plan optimization, treatment delivery, and catheter removal. Eight patients underwent interstitial brachytherapy treatment after chemotherapy & EBRT between January 2018 and November 2022. A summary of techniques is presented, including freehand interstitial catheter placement, tandem & cylinder with interstitial needles, & placement with a Syed applicator (examples depicted in Figure 1). Prior to brachytherapy, EBRT doses ranged from 45-54 Gy in 25-30 fractions. The selected boost prescription dose was chosen based upon prior EBRT dose and proximity to OARs. Median high-risk CTV volume was 7.1 cc (range: 2 cc - 130 cc). Median boost dose was 20 Gy in 5 fractions (range: 20-30 Gy in 5 fractions) delivered twice daily, at least 6 hours apart. Median needles placed was 6 (range: 3 - 20). The median D90 was 21.63 Gy (range: 19.85 - 29.86 Gy). The median V200 was 23.3% (range: 8.20% to 29.82%), the median V150 was 49.05% (range: 24.96% - 60.80%) and median V100 was 93.5% (range: 89.7% to 97.93%). One patient experienced sub-acute soft tissue necrosis requiring local wound care. Interstitial brachytherapy for LAVC is a feasible method of dose-escalation in patients with vulvar cancer, with potential dosimetric advantages over traditional EBRT boosts. Integration of brachytherapy techniques in the vulvar cancer setting have the potential to improve patient outcomes & local control. Care should be taken to control dose heterogeneity to minimize the risk of soft tissue necrosis. Further investigations are warranted to guide optimal dosimetry, constraints and coverage, as well as to compare against traditional outcomes utilizing EBRT boosts for LAVC. [ABSTRACT FROM AUTHOR]

• The factors affecting the mobilized length of anchor force are studied. • The strain diagram method is proposed to analyse the anchor force mechanism for partial mobilized length. • A new analytical solution which can determine the occurrence of pipeline walking and the mobilized length of the anchor force, while considering a range of factors such as pipeline parameters, load parameters, and contact parameters is proposed. • To address the problem of large anchor force at the end anchor, a flexible anchor is proposed to reduce the anchor force, and a formula for predicting the flexible anchor force is fitted. The deep-sea pipeline exposed on the seabed is prone to pipeline walking under the influence of thermal loading cycles. Anchors are commonly used to prevent the pipeline walking from causing the end connection of the pipeline system to break. The development of a simple and practical method for calculating anchor force is essential for the preliminary design of the project. In this paper, a finite element model for calculating anchor force is established, and the factors affecting the accumulated length of effective axial force are analyzed. A strain diagram method is proposed for calculating the anchor force under partial accumulated length, and an analytical solution for the rigid anchor force is derived based on the strain diagram method. To address the problem of large anchor force at the end anchor, a flexible anchor is proposed to reduce the anchor force, and a formula for predicting the flexible anchor force is fitted. The study shows that the accumulated length proportion of anchor force increases with the increase of loading temperature and SCR tension, and decreases with the increase of pipeline length and friction coefficient. Flexible anchors can significantly reduce the anchor force. The proposed analytical solution for anchor force can comprehensively consider the influence of factors such as pipeline length, SCR tension, loading temperature, and friction coefficient, and has certain advantages over traditional analytical solutions. [ABSTRACT FROM AUTHOR]

Understanding the mechanical characteristics of frozen soil is critical for engineering projects in cold regions. A series of case studies were conducted to explore the macroscopic and microscopic mechanical behavior of frozen soil during four different stress paths, i.e., isotropic, constant stress ratio, conventional triaxial, and true triaxial compression tests, using the distinct element method (DEM). The particle-scale mechanism and temperature effect of frozen soil are also taken into account in the DEM simulation. The results indicate that the peak stress/yield stress of frozen soil decreases with the increase of temperature or decrease of stress ratio or decrease of intermediate principal stress ratio b, which is related to the evolutions of bond breakage, bond stress, mechanical coordination number, and deviatoric fabric. When 0.25 ≤ b ≤ 0.75, the direction of strain increment deviates from the direction of stress. In addition, the relationship between the damage variable B and the volumetric strain εv or shear stain εs can be expressed as B = 1 - exp (- a · ε v n) or B = 1 - exp (- a · ε s n) under different stress paths. The simulation results and revealed microscopic mechanism will be valuable in developing breakage-mechanics-based constitutive models for frozen soil. [ABSTRACT FROM AUTHOR]

The application of Li‐metal‐anodes (LMA) can significantly improve the energy density of state‐of‐the‐art lithium ion batteries. Lots of new electrolyte systems have been developed to form a stable solid electrolyte interphase (SEI) films, thereby achieving long‐term cycle stability of LMA. Unfortunately, the common problem faced by these electrolytes is poor oxidation stability, which rarely supports the cycling of high‐voltage Li‐metal batteries (LMBs). In this work, a new single‐component solvent dimethoxy(methyl)(3,3,3‐trifluoropropyl) silane is proposed. The electrolyte composed of this solvent and 3 m LiFSI salt successfully supports the long‐term cycle stability of limited‐Li (50 µm)||high loading LiCoO2 (≈20 mg cm−2) cell at 4.6 V. Experiments and theoretical research results show that the outstanding performance of the electrolyte in high‐voltage LMBs is mainly attributed to its unique solvation structures and its great ability to build a highly stable and robust interphase on the surface of LMA and high‐voltage cathodes. Interestingly, this proposed electrolyte system builds a stable SEI film rich in LiF and Li3N on the surface of LMA by improving the two‐electron reduction activity of FSI− without adding LiNO3, the well‐known additive used for LMBs. The design idea of the proposed electrolyte can guide the development of high‐voltage LMBs. [ABSTRACT FROM AUTHOR]

Experiments are performed to study the closed-loop effect of gas hydrate formation and decomposition on the flow properties of a fine-grained quartz sand specimen. The high resolution X-ray CT images of the test specimen at different experimental stages are acquired. In order to elucidate the changes in pore structure of the test specimen, topologically representative pore networks are established. The evolution of the flow properties during gas hydrate formation and decomposition is further evaluated. The results show that, gas hydrates occupancy in pore space exhibit different modes; they grow mainly as the grain-cementing mode except some intermediate stages, where pore-filling or load-bearing hydrates are observed. It is also found that the formation and decomposition of gas hydrates can cause the pore structure and flow properties changed. Increase of gas hydrate saturation results in a sharp decline in water relative permeability, larger irreducible water saturation and smaller gas-water percolation zone, while gas relative permeability does not exhibit obvious changing law. The decomposition of gas hydrates will exert a greater influence on the flow properties described above than gas hydrate formation does. The increase in frequency percentage of 10–20 μm pores within the fine-grained test specimen after experiments might be caused by gas hydrate decomposition induced damage of pore structure. [ABSTRACT FROM AUTHOR]

Porous anorthite ceramics are widely applied as catalysis supports, separation membranes, and thermal insulations at high temperatures. In situ formation of anorthite crystals during vitrification is herein employed to improve mechanical properties of porous anorthite with modulated grain sizes on pore walls. Sintering parameters of shrinkage (5%–30%), open porosity (31.0%–58.3%), density (1.18–1.71 g/cm3), and mass loss (12.20%–18.26%) are estimated to investigate the influences of sintering aids of calcite, fused mullite, and silicon carbide or talcum on the densification processes of porous anorthite. The Kissinger equation is used to determine the activation energy of 783 kJ/mol for the crystallization of anorthite, which is significantly low for the formation of anorthite crystals through surface nucleation mechanism in present flux‐rich melt. In situ crystallization and simultaneous densification under liquid drainages are favored for whiskers‐reinforced mechanism to enhance flexural strengths (6.9–19.4 MPa) for porous anorthite with the porosity of 49.6%–58.3% through the formation of hierarchical nano‐ and microscale structures during vitrification. [ABSTRACT FROM AUTHOR]

• Based on the suction penetration test of bucket foundation, the distribution regularity of the excess porewater pressure of soil and soil pressure on both sides of bucket wall and bucket end are revealed. • Based on finite element method, the seepage characteristics of the bucket foundation during the penetration process are analyzed, and the change regularity of the effective stress and resistance of soil during the penetration process of bucket foundation is obtained. • Considering the effect of effective stress on seepage, a calculation method for required suction of bucket foundation with few easy-obtained parameters is established. The accurate estimation of penetration resistance of the bucket foundation is the key step for its installation, and the core part of the estimation of the penetration resistance is the exact prediction of the drag reduction effect due to suction. Therefore, in the present paper, the change regularity of the excess porewater pressure along the bucket wall and at the tip is analyzed by combining the model test and finite element analysis method, along with the soil pressure of the bucket foundation during the suction penetration process in sand. The results showed that, during the suction penetration process of the bucket foundation, the soil pressure and excess porewater pressure change approximately linearly with the depth of the bucket wall, and the reduction degree of lateral resistance due to seepage increases in a power function growth trend. Based on the effective stress principle of soil and basic theory of seepage and considering the effect of seepage on penetration resistance, the change regularity of the effective stress of soil along the bucket wall during the penetration process is obtained. Besides, the calculation method for penetration resistance and required suction of bucket foundation in sand soil is established, and the effectiveness of the present method is verified by comparing with the model test and engineering case, which can provide theoretical basis for engineering design and construction of bucket foundation. [ABSTRACT FROM AUTHOR]