Rate Enhancement Research Articles

Raman Monitoring of the Electro-Optical Synergy-Induced Enhancements in Carbon-Bromine Bond Cleavage, Reaction Rate, and Product Selectivity of p-Bromothiophenol.

Electro-optical synergy has recently been targeted to improve the separation of hot carriers and thereby further improve the efficiency of plasmon-mediated chemical reactions (PMCRs). However, the electro-optical synergy in PMCRs needs to be more deeply understood, and its contribution to bond dissociation and product selectivity needs to be clarified. Herein, the electro-optical synergy in plasmon-mediated reduction of p-bromothiophenol (PBTP) was studied on a plasmonic nanostructured silver electrode using in situ Raman spectroscopy and theoretical calculations. It was found that the electro-optical synergy-induced enhancements in the cleavage of carbon-bromine bonds, reaction rate, and product selectivity (4,4'-biphenyl dithiol vs thiophenol) were largely affected by the applied bias, laser wavelength, and laser power. The theoretical simulation further clarified that the strong electro-optical synergy is attributed to the matching of energy band diagrams of the plasmonic silver with those of the adsorbed PBTP molecules. A deep understanding of the electro-optical synergy in PBTP reduction and the clarification of the mechanism will be highly beneficial for the development of other highly efficient PMCRs.

Mass-Based Hybrid Nanofluid Model for Thermal Radiation Analysis of MHD Flow over a Wedge Embedded in Porous Medium

This study addresses the intricate interplay of magnetohydrodynamics (MHD), thermal radiation, and porous media effects, which are crucial in numerous engineering applications, including aerospace, energy systems, and environmental processes. The development of a mass-based hybrid nanofluid model signifies a novel approach, potentially yielding more accurate predictions and insights into the thermal behavior of fluids in diverse scenarios. Thus, the current research explores the heat transfer characteristics of a unique nanofluid known as TiO2 (titania)-CuO (copper oxide)/H2O (water) hybrid nanofluid. This nanofluid flows past a static or moving wedge considering the impact of thermal radiation and magnetic field in the appearance of porous medium. To calculate the effective thermophysical attributions of the hybrid (TiO2-CuO) nanofluid, a mass-based strategy is employed. This approach involves analyzing the masses of both the first and second nanoparticles, along with the mass of the base fluid, as essential input parameters. The proposed mathematical model is modified to a dimensionless form by applying similarity transformations. The numerical solution is obtained by utilizing the bvp4c built-in function within the MATLAB environment. Graphs illustrate the influence of various parameters on temperature and velocity trends, including the magnetic field parameter and heat absorption/generation parameter as well as the thermal radiation parameter. It is noted that along with the enhancement in the values of parameters related to porous medium or magnetic field, the velocity of the hybrid nanofluid improves. This occurs when the moving wedge parameter’s value is below 1. Conversely, when the moving wedge parameter’s value exceeds 1, the velocity of the hybrid nanofluid decreases. The shape factor is more effective in the temperature profile for developed inputs of heat absorption/generation parameter. A juxtaposition of enhancement in heat transfer rate due to nanofluid (TiO2/H2O) and hybrid nanofluid (TiO2-CuO/H2O) is likewise presented. The main outcome indicates that the hybrid nanofluid exhibits superior thermal conductivity relative to the conventional nanofluid.

Impact of stage-specific limb function exercises guided by a self-management education model on arteriovenous fistula maturation status.

The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula (AVF). However, due to the lack of a unified exercise standard in China, many patients have insufficient awareness of the importance of AVF, leading to poor effectiveness of limb function exercise. The self-management education model can effectively promote patients to take proactive health-related actions. This study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in factors such as the maturity of AVF. To assess the impact of stage-specific limb function exercises, directed by a self-management education model, on the maturation status of AVFs. This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan Province, China. Patients were randomly divided into an observation group and a control group using a random number table method. The observation group underwent tailored stage-specific limb function exercises, informed by a self-management education model which took into account the unique features of AVF at various stages, in conjunction with routine care. Conversely, the control group was given standard limb function exercises along with routine care. The assessment involves the maturity of AVFs post-intervention, postoperative complications, and the self-management level of the fistula in both groups patients. Analyses were conducted using SPSS version 23.0. Count data were represented by frequency and percentage and subjected to chi-square test comparisons. Measurement data adhering to a normal distribution were presented as mean ± SD. The independent samples t-test was utilized for inter-group comparisons, while the paired t-test was used for intra-group comparisons. For measurement data not fitting a normal distribution, the median and interquartile range were presented and analyzed using the Wilcoxon rank sum test. At the 8-wk postoperative mark, the observation group demonstrated significantly higher scores in AVF symptom recognition, symptom prevention, and self-management compared to the control group (P < 0.05). However, the variance in symptom management scores between the observation and control groups lacked statistical significance (P > 0.05). At 4 wk after the operation, the observation group displayed a superior vessel diameter and depth from the skin of the drainage vessels in comparison to the control group (P < 0.05). While the observation group did manifest elevated blood flow rates in the drainage vessels relative to the control group, this distinction was not statistically significant (P > 0.05). By the 8-wk postoperative interval, the observation group outperformed the control group with notable enhancements in blood flow rates, vessel diameter, and depth from the skin of drainage vessels (P < 0.01). Seven days following the procedure, the observation group manifested significantly diminished limb swelling and an overall reduced complication rate in contrast to the control group (P < 0.05). The evaluation of infection, thrombosis, embolism, arterial aneurysm stenosis, and incision bleeding showed no notable differences between the two groups (P > 0.05). By the 4-wk postoperative juncture, complications between the observation and control groups were statistically indistinguishable (P > 0.05). Stage-specific limb function exercises, under the guidance of a self-management education model, amplify the capacity of AVF patients to discern and prevent symptoms. Additionally, they expedite AVF maturation and mitigate postoperative limb edema, underscoring their efficacy as a valuable method for the care and upkeep of AVF in hemodialysis patients.

Formulation and Characterization of Clozapine Nanosuspension as a Sublingual Film

Background: Clozapine (CLZ) is a potent antipsychotic drug that suppresses the symptoms of schizophrenia and mania. Clozapine falls into Class II (BCS); its poor bioavailability is attributed to low water solubility and an extensive first-pass effect. Objective: To prepare CLZ as a nanosuspension (NS) to improve its low water solubility and load it into a sublingual film to enhance oral bioavailability. Methods: CLZ nanosuspensions are prepared by the “solvent anti-solvent precipitation” method using Soluplus as a stabilizing agent. We evaluated the polydispersity index (PDI) and the particle size of the CLZ nanosuspension formulations. The optimized formula of CLZ nanosuspension is loaded directly onto a sublingual thin film, eliminating the need for freeze-drying for solidification by the solvent casting approach. The sublingual films were characterized by thickness, surface pH, folding endurance, disintegration time, and in vitro dissolution rate. Results: We selected the formula F1 sublingual film as the best, as it demonstrated a uniform thickness of 0.087mm, good flexibility, and a surface pH of 6.7. It disintegrated quickly in 13 seconds and had a faster in vitro dissolution rate (3 min) compared to the CLZ ordinary films. Conclusions: The results confirmed the success of CLZ NS as a sublingual thin film for dissolution rate enhancement, which may improve oral bioavailability.

Hydrolysis of Nerve Agent Simulants Accelerated by Stimuli-Responsive Dinuclear Catalysts.

The ability to control the catalytic activity of enzymes in chemical transformations is essential for the design and development of artificial catalysts. Herein, we report the synthesis and characterization of functional ligands featuring two 1,4,7,10-tetraazacyclododecane units linked by an azobenzene group and their corresponding dinuclear Zn(II) complexes. We show that the configuration switching (E/Z) of the azobenzene spacer in the ligands and their dinuclear Zn(II) complexes is reversibly controlled by irradiation with UV and visible light. The Zn(II)-metal complexes are light-responsive catalysts for the hydrolytic cleavage of nerve agent simulants, i.e., p-nitrophenyl diphenyl phosphate and methyl paraoxon. The catalytic activity of the Z-isomers of the dinuclear Zn(II) complexes outperformed that of the E-counterparts. Moreover, combining the less active E-isomers with gold nanoparticles induced an enhancement in the hydrolysis rate of p-nitrophenyl diphenyl phosphate. Kinetic analysis has shown that the catalytic site appears to involve a single metal ion. We explain our results by considering the different desolvation effects occurring in the catalyst's configurations in the solution and the catalytic systems involving gold nanoparticles.

Dynamic control of spontaneous emission using magnetized InSb higher-order-mode antennas

Abstract We exploit InSb’s magnetic-induced optical properties to design THz sub-wavelength antennas that actively tune the radiative decay rates of dipole emitters at their proximity. The proposed designs include a spherical InSb antenna and a cylindrical Si-InSb hybrid antenna that demonstrate distinct behaviors. The former dramatically enhances both radiative and non-radiative decay rates in the epsilon-near-zero region due to the dominant contribution of the Zeeman splitting electric octupole mode. The latter realizes significant radiative decay rate enhancement via magnetic octupole mode, mitigating the quenching process and accelerating the photon production rate. A deep learning-based optimization of emitter positioning further enhances the quantum efficiency of the proposed hybrid system. These novel mechanisms are promising for tunable THz single-photon sources in integrated quantum networks.

Development of Ln(III) Derivatives as 19F Parashift Probes.

19F parashift probes with paramagnetically shifted reporter nuclei provide attractive platforms to develop molecular imaging probes. These probes enable ratiometric detection of molecular disease markers using a direct detection technique. Here, we describe a series of trivalent lanthanide (Ln(III)) complexes that are structural analogues of the clinically approved MR contrast agent (CA) ProHance to obtain LnL 19F parashift probes. We evaluated trans-gadolinium paramagnetic lanthanides compared to diamagnetic YL for 19F chemical shift and relaxation rate enhancement. The paramagnetic contribution to chemical shift (δPCS) for paramagnetic LnL exhibited either shifts to lower frequency (δPCS < 0 for TbL, DyL, and HoL) or shifts to higher frequency (δPCS > 0 for ErL, TmL, and YbL) compared to YL 19F spectroscopic signal. Zero-echo time pulse sequences achieved 56-fold sensitivity enhancement for DyL over YL, while developing probe-specific pulse sequences with fast delay times and acquisition times achieved 0.6-fold enhancement in limit of detection for DyL. DyL provides an attractive platform to develop 19F parashift probes for ratiometric detection of enzymatic activity.

The β-subunit of tryptophan synthase is a latent tyrosine synthase.

Aromatic amino acids and their derivatives are diverse primary and secondary metabolites with critical roles in protein synthesis, cell structure and integrity, defense and signaling. All de novo aromatic amino acid production relies on a set of ancient and highly conserved chemistries. Here we introduce a new enzymatic transformation for L-tyrosine synthesis by demonstrating that the β-subunit of tryptophan synthase-which natively couples indole and L-serine to form L-tryptophan-can act as a latent 'tyrosine synthase'. A single substitution of a near-universally conserved catalytic residue unlocks activity toward simple phenol analogs and yields exclusive para carbon-carbon bond formation to furnish L-tyrosines. Structural and mechanistic studies show how a new active-site water molecule orients phenols for a nonnative mechanism of alkylation, with additional directed evolution resulting in a net >30,000-fold rate enhancement. This new biocatalyst can be used to efficiently prepare valuable L-tyrosine analogs at gram scales and provides the missing chemistry for a conceptually different pathway to L-tyrosine.

The Effect of Feeding with Chironomid and Artemia on Fatty Acids and Amino Acids Profiles in Persian Sturgeon (Acipenser persicus) Larvae

This study aimed to examine the effect of various live foods on the fatty acids (FAs) and amino acids (AAs) profiles in Persian sturgeon (Acipenser persicus) larvae. One thousand and two hundred larvae were cultured in circular concrete tanks, and four treatments were administered as: (1) Artemia + Daphnia, (2) Artemia, (3) Artemia + Chironomid, and (4) Chironomid. Each treatment was considered as three replicates over an 11-day period. At the end of the experiment, treatment 1 (Artemia + Daphnia) showed the highest average weight of larvae, and the lowest weight was observed in treatment 4 (Chironomid). Survival rate ranged from 83.84% to 88.86% and no significant difference was observed among the groups (P &gt;0.05). Among Artemia-fed larvae, the predominant FAs were docosahexaenoic acid (DHA), oleic acid (ω9), and monounsaturated fatty acids (MUFA), while saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) (ω3 + ω6) were present in a lesser proportion (P &lt;0.05). In larvae fed with Artemia and Daphnia, the predominant proportions were observed in SFAs, eicosapentaenoic acid (EPA), ω3, DHA + EPA, and the n3/n6 ratio, all registering the highest percentages. Conversely, MUFA, ω6, and the DHA/EPA ratio displayed the lowest percentages (P &lt;0.05). Moreover, larvae fed with Artemia exhibited higher levels of ω6, PUFA (ω3 + ω6), and DHA/EPA ratio. In contrast, larvae fed with Chironomid showed lower levels of EPA, DHA + EPA, and n3/n6 ratio (P &lt;0.05). Among larvae fed with Chironomid, solely the DHA/EPA ratio exhibited a higher value compared to larvae fed with Artemia and Daphnia (P &lt;0.05). The amount of leucine in fish fed Artemia + Daphnia was more than the other treatments (P &lt;0.05). This study revealed a significant difference in amino acids composition among various live foods (P &lt;0.05), but no significant difference in AAs was observed in the body of Persian sturgeon larvae (P &gt;0.05). The results of this study suggest that the Persian sturgeon larvae possess the ability to maintain a balanced state of AAs. It is also evident that the FA profile of different live foods can affect the overall FA levels in the body of Persian sturgeon larvae, ultimately contributing to the enhancement of fish survival rate and growth.

Estimation of Artificial Reef Pose Based on Deep Learning

Artificial reefs are man-made structures submerged in the ocean, and the design of these structures plays a crucial role in determining their effectiveness. Precisely measuring the configuration of artificial reefs is vital for creating suitable habitats for marine organisms. This study presents a novel approach for automated detection of artificial reefs by recognizing their key features and key points. Two enhanced models, namely, YOLOv8n-PoseRFSA and YOLOv8n-PoseMSA, are introduced based on the YOLOv8n-Pose architecture. The YOLOv8n-PoseRFSA model exhibits a 2.3% increase in accuracy in pinpointing target key points compared to the baseline YOLOv8n-Pose model, showcasing notable enhancements in recall rate, mean average precision (mAP), and other evaluation metrics. In response to the demand for swift identification in mobile fishing scenarios, a YOLOv8n-PoseMSA model is proposed, leveraging MobileNetV3 to replace the backbone network structure. This model reduces the computational burden to 33% of the original model while preserving recognition accuracy and minimizing the accuracy drop. The methodology outlined in this research enables real-time monitoring of artificial reef deployments, allowing for the precise quantification of their structural characteristics, thereby significantly enhancing monitoring efficiency and convenience. By better assessing the layout of artificial reefs and their ecological impact, this approach offers valuable data support for the future planning and implementation of reef projects.

Nitrogen adsorption induced surface kinetics changes of diamond growth by microwave plasma CVD

The strong temperature dependence of the contribution of nitrogen to diamond growth enhancement by microwave plasma chemical vapor deposition (MPCVD) have been firstly reported and systematically studied. Generally, an enhanced hydrogen desorption from the growing surface induced by the incorporated nitrogen atoms in diamond sublayer has been successfully used to explain the weak temperature depended growth enhancement of diamond by nitrogen addition, but cannot be employed to explain the observed strong temperature dependence of nitrogen contribution to diamond growth enhancement observed in this work. This indicates a significant change of surface kinetics of diamond growth induced by nitrogen addition should be occurred around 700 °C where a maximum value achieved. At this relative low temperature, the growing surface sites should be almost fully covered with hydrogen atoms with relative low nitrogen incorporated in the diamond. The adsorbed nitrogen may then make a contribution to promote hydrogen desorption, which is believed to play a dominant role in affecting the contribution of nitrogen. Experimental and calculation results do show that both the nitrogen adsorbed on the growing surface and incorporated in the sublayer may have different contribution to the growth rate enhancement, resulting in strong and weak temperature dependence, respectively.

Advances in the Design of Functional Cellulose Based Nanopesticide Delivery Systems.

The advancement of science and technology, coupled with the growing environmental consciousness among individuals, has led to a shift in pesticide development from traditional methods characterized by inefficiency and misuse toward a more sustainable and eco-friendly approach. Cellulose, as the most abundant natural renewable resource, has opened up a new avenue in the field of biobased drug carriers by developing cellulose-based drug delivery systems. These systems offer unique advantages in terms of deposition rate enhancement, modification facilitation, and environmental impact reduction when designing nanopesticides. Consequently, their application in the field of nanoscale pesticides has gained widespread recognition. The present study provides a comprehensive review of cellulose modification methods, carrier types for cellulose-based nanopesticides delivery systems (CPDS), and various stimulus-response factors influencing pesticide release. Additionally, the main challenges in the design and application of CPDS are summarized, highlighting the immense potential of cellulose-based materials in the field of nanopesticides.

Analytical and numerical investigation for viscoelastic fluid with heat transfer analysis during rollover-web coating phenomena

Abstract The current study theoretically and computationally analyses the viscoelastic Sisko fluids during the non-isothermal rollover web phenomenon. The mathematical modeling produces a system of partial differential equations, which we further simplify into ordinary differential equations through appropriate transformations. We have formulated the problem based on the lubrication approximation theory. The solution has been obtained with the perturbation method, and the outcomes are found in mathematical, tabular, and graphical forms that highlight the influence of pertinent parameters on velocity profiles, pressure gradients, flow rates per unit width, Nusselt number, pressure profile, temperature distributions, and other significant engineering quantities. Further, A comparative analysis between analytic and numerical solutions, utilizing the middefer method in the Maple environment, demonstrates reasonable agreement. Also, we observe that the fluid parameter significantly influences both velocity and temperature profiles. Moreover, the determination of a separation point 2.5000, accompanied by the observation of a maximum coating thickness of 0.6960. The enhancement in fluid heat transfer rate is approximately 5% compared to non-Newtonian fluid parameter values, with potential for further improvement by increasing the non-Newtonian parameter values. This comprehensive investigation offers valuable insights for practical implementation and future scholarly endeavors, with zero-order findings showcasing enhanced precision.

A flexible self-cleaning/antibacterial PVDF/T-ZnO fabric based on piezo-photocatalytic coupling effect for smart mask

A novel flexible composite fabric has been engineered by combining piezoelectric poly (vinylidene fluoride) (PVDF) and tetrapod zinc oxide (T-ZnO) nanostructures, which are integrated onto a nonwoven fabric substrate. This fabric exhibits a wide array of functionalities, notably self-cleaning and antibacterial properties, facilitated by the synergistic piezo-photocatalytic coupling effect. Through the utilization of the piezoelectric effect inherent in PVDF/T-ZnO in tandem with the photocatalytic attributes of T-ZnO nanostructures, the fabric achieves concurrent degradation of organic pollutants and antibacterial efficacy when exposed to mechanical vibration and solar irradiation. The piezo-photocatalytic coupling effect engenders an internal electric field that aids in the effective separation of photo-generated carriers (electrons and holes), thereby diminishing recombination rates and augmenting the efficiency of the photocatalytic degradation process. Notably, organic pollutants such as methylene blue and azithromycin exhibit degradation levels of 96.0% and 92.6%, respectively, within a timeframe of 25 and 60 min. The incorporation of PVDF/T-ZnO results in an approximate 40% enhancement in the degradation rate of organic substances compared to the use of T-ZnO in isolation. Furthermore, the composite fabric showcases exceptional antibacterial efficacy, effectively inhibiting the proliferation of Staphylococcus aureus. Experimental findings reveal that the average antibacterial zone diameter of the PVDF/T-ZnO fabric measures at 7.68 mm, significantly surpassing that of the T-ZnO fabric and nonwoven fabric. Given its remarkable self-cleaning and antibacterial attributes, the PVDF/T-ZnO fabric exhibits substantial potential for diverse applications, including the development of intelligent masks tailored for deployment in healthcare settings and polluted environments.

Flexible and rigid block copolymers from recyclable polyesters

The paper addresses a study on the thermoplastic elastomers (TPE) that can be synthesized using monomers retrieved from the chemically recycled semi-aromatic polyesters, such as terephthalic acid from low value stream recyclable polyethylene terephthalate (rPET). In contrast to PET, because of their physical and mechanical properties, TPEs are often used as an engineering polymer in automotive and consumer goods. The understanding of the crystallization and phase behavior of these materials is crucial to fine-tune the molecular structure and properties. We explore the interplay between the crystallization and phase separation in these materials by performing experiments on model thermoplastic elastomers consisting of polybutylene terephthalate (PBT) and polytetrahydrofuran (PTHF). A common denominator in the synthesis of PBT is terephthalic acid that can be obtained from Dimethyl Terephthalate (DMT) or recycling used PET. We show that by varying the compositions and block length of different blocks, in PBT-PTHF block copolymers, morphological variations from spherulites to dendrites can be induced, which could be captured using optical microscopy. By performing rheological and small angle X-ray scattering studies, we correlate these morphological variations at microscopic length scales, to the chain architecture at nanometer length scales. Our observations reveal that at the higher rigid PBT content, the process of phase separation strongly influences the crystallization kinetics that promotes the lamellar structure of the semi-crystalline polymer, observed at room temperature. On the other hand, in the presence of higher soft block content, the crystal growth occurs with minimal influence of the microphase separation. In broader generality, no morphological differences in the TPEs synthesized using the terephthalic acid from rPET are found. However, when the monomer from rPET is used, enhancement in crystallization rate occurs in the TPEs having similar molar mass and molecular configuration. We attribute the enhanced crystallization rate to the catalyst residues present in the terephthalic acid obtained fom rPET.

Real-Time EtherCAT-Based Control Architecture for Electro-Hydraulic Humanoid

Electro-hydraulic actuators have witnessed significant development over recent years due to their remarkable abilities to perform complex and dynamic movements. Integrating such an actuator in humanoids is highly beneficial, leading to a humanoid capable of performing complex tasks requiring high force. This highlights the importance of safety, especially since high power output and safe interaction seem to be contradictory; the greater the robot’s ability to generate high dynamic movements, the more difficult it is to achieve safety, as this requires managing a large amount of motor energy before, during, and after the collision. No matter what technology or algorithm is used to achieve safety, none can be implemented without a stable control system. Hence, one of the main parameters remains the quality and reliability of the robot’s control architecture through handling a huge amount of data without system failure. This paper addresses the development of a stable control architecture that ensures, in later stages, that the safety algorithm is implemented correctly. The optimum control architecture to utilize and ensure the maximum benefit of electro-hydraulic actuators in humanoid robots is one of the important subjects in this field. For a stable and safe functioning of the humanoid, the development of the control architecture and the communication between the different components should adhere to some requirements such as stability, robustness, speed, and reduced complexity, ensuring the easy addition of numerous components. This paper presents the developed control architecture for an underdeveloped electro-hydraulic actuated humanoid. The proposed solution has the advantage of being a distributed, real-time, open-source, modular, and adaptable control architecture, enabling simple integration of numerous sensors and actuators to emulate human actions and safely interact with them. The contribution of this paper is an enhancement of the updated rate compared to other humanoids by 20% and by 40 % in the latency of the master. The results demonstrate the potential of using EtherCAT fieldbus and open-source software to develop a stable robot control architecture capable of integrating safety and security algorithms in later stages.

Heating and storage of medium-deep borehole heat exchangers: Analysis of operational characteristics via an optimized analytical solution model

This study focuses on investigating the thermal storage potential of medium-deep borehole heat exchanger (MDBHE) to address the issues of temperature attenuation of thermal reservoir and heating capacity reduction during the one-way heat extraction process in the heating period. By establishing an MDBHE heating system that integrates an external thermal storage source, a comprehensive analysis of the heat transfer progress and operational characteristics of the MDBHE is conducted, including optimizing burial depth, thermal storage scenarios, and aquifer conditions. The calculated solution under the typical thermal storage conditions (S60–30) in this study reveals that the average heat supply capacity increasement of a 1200 m MDBHE is 37.2 % higher than that of a 2000 m MDBHE, and the power consumption of the circulating water pump also can be reduced by 40 % in heating period. Furthermore, the enhancement of storage temperature and flow rate both contribute to a noticeable improvement in the heating performance of the MDBHE during the heating period. The heat transfer power and energy efficiency of MDBHE both increase with the elevation of seepage velocity and aquifer thickness during the energy storage and heating period. The significance of this research lies in its contribution to the enhancement of thermal storage and heat transfer efficiency in MDBHE and offering novel insights for the multi-thermal energy storage systems.

Micro- and Mesoporous Structural Effects of Beta Zeolites for Volatile Organic Compound Sorption.

To fully exploit pore engineering in the design of more efficient zeolite adsorbents for volatile organic compound (VOC) treatment, the roles of meso- and micropores need to be clarified to provide the theoretical basis and feasible measures. In this work, the three VOC sorption properties of conventional and hierarchical porous beta zeolites were comparatively investigated to study the roles of meso- and micropores. There is a division of functions between micro- and mesopores, with micropores being the main VOC adsorption sites and mesopores greatly enhancing VOC diffusion and adsorbent reusability. On the one hand, micropores should be preserved as much as possible because obtaining mesopores by sacrificing micropores (i.e., alkali treatment) results in 28-60% decreases in adsorption capacities. On the other hand, mesopore introduction is highly desirable, which results in an enhancement of VOC intraparticle diffusion rates by 1.3-2.3 times (at the VOC concentration of 600 ppm) and chlorobenzene adsorption capacity on the 20th cycle increasing from 78% of the initial value to 89 and 93%. The findings may provide valuable information about zeolite-based adsorbents for adsorption removal or recovery of VOCs.

Integrating intrinsic and configural superiority into advanced impact-resistant organohydrogels via cryo-assisted direct ink writing

The growing safety consciousness towards life and engineering poses demand for efficient anti-impact materials. Decent advances have been made in material development and structure design, whereas the superiority synergism of materials and structures remains challenging. This work develops an advanced impact-resistant shear stiffening gel-polyvinyl alcohol-chitosan (SSG-PVA-CS) organohydrogel by integrating 3D printed customized architectures with strain rate enhanced matrix materials. Following rheological optimization of components, the precursor ink presents shear thinning and yield stress fluid behaviors enabling the direct ink writing (DIW) printing techinique. The printability is systemically explored through finite element modeling assisted flow dynamics analysis and experimental validating, and a quantitative phase diagram is constructed which determines the dependence of parameters on the printing mode and quality. The organohydrogel presents favorable mechanical strength, cyclic durability and rate enhancement effect, which imparts basis of impact resistance to the matrix. The rational structure design effectively reduces the volume density within 0.60 to 0.71 g/cm3 while maintaining considerable attenuation ratios of 73.09 % to 83.55 %, with structure-dependent dynamic mechanical behaviors clarified via finite element analysis. This study provides a reliable approach to fabricate impact-resistance materials with tailored architectures and mechanically functional matrix materials, unlocking paths to break through the performance bottleneck.

Bioceramic filled PLA based nanocomposites for biomedical application: An experimental investigation

Orthopedic implants require innovative biodegradable materials to eliminate the need for a second surgery post-healing and to counteract the stress shielding issues associated with conventional metallic implants. Polylactic acid (PLA) was chosen for its biocompatibility and biodegradability within the human body. Hydroxyapatite (HAP) and eggshell nanoparticles (ESNPs) were selected as bioceramics due to their similarity to the major constituents of human bone. In the present study, ESNPs were prepared through a ball mill. HAP and Mg particles coated with TiO2 (TiO2@Mg) were synthesized through chemical precipitation and the sol-gel technique, respectively. Subsequently, four samples were prepared: PLA/ESNP/Mg (PEM), PLA/HAP/Mg (PHM), PLA/ESNP/TiO2@Mg (PEMT), and PLA/HAP/TiO2@Mg (PHMT) using the solvent casting process. The addition of Mg demonstrated an enhancement of degradation rates, and TiO2@Mg served to eliminate hydrogen release from Mg. The confirmation of synthesized NPs and PLA nanocomposites was validated through Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), and Field-Emission Scanning Electron Microscopy (FE-SEM) analysis. The prepared PEMT and PHMT showed tensile strength (42.70 ± 7.55 MPa and 31.57 ± 3.84 MPa), tensile modulus (1624.49 ± 155.05 MPa and 1674.25 ± 87.04 MPa), and shore D hardness (79.41 ± 2.40 SHN and 77.81 ± 3.18 SHN), respectively. The findings showed that PEMT and PHMT composites exhibited enhanced surface roughness, hydrophilicity, degradation rate, and swelling behavior compared to PEM and PHM samples. Moreover, the viability of MG63 cells cultured in different diluted extracts of both samples reached approximately 80 %, indicating no observable cytotoxicity and a hemolysis rate of less than 1.4 %, indicating the potential for use in maxillofacial region implants.