Search Results (130)

The presented research examines the performance characteristics of Brazed Plate Heat Exchangers through computational fluid dynamics (CFD), focusing on pressure drop calculations for single-phase flow within full channels of plates featuring dimpled corrugation. This work aims to bridge gaps in the literature, particularly regarding the underexplored behavior near the ports for the studied technology and establishing a framework for future conjugate heat transfer studies. A methodology for the domain generation was developed, integrating a preliminary forming simulation to reproduce the complex plate geometry. Comprehensive sensitivity analyses were conducted to evaluate the influence of different parameters and identify the optimal settings for obtaining reliable results. The findings indicate that the $k-\epsilon$ realizable turbulence model with enhanced wall treatment offers superior accuracy in predicting pressure drops, with errors within ±4.4%. Additionally, leveraging the information derived from CFD, a strategy to estimate contributions from different channel sections without a direct reliance on those simulations was developed, offering practical implications for plate design. Full article

Infrared thermography is a common approach used in building inspection for identifying building envelope thermal anomalies that cause energy loss and occupant thermal discomfort. Detecting these anomalies is essential to improve the thermal performance of energy-inefficient buildings through energy retrofit design and correspondingly reduce operational energy costs and environmental impacts. A thermal bridge is an unwanted conductive heat transfer. On the other hand, an infiltration/exfiltration anomaly is an uncontrollable convective heat transfer, typically happening around windows and doors, but it can also be due to a defect that comprises a building envelope’s integrity. While the existing literature underscores the significance of automatic thermal anomaly identification and offers insights into automated methodologies, there is a notable gap in addressing an automated workflow that leverages building envelope component segmentation for enhanced detection accuracy. Consequently, an automatic thermal anomaly identification workflow from visible and thermal images was developed to test it, utilizing segmented building envelope information compared to a workflow without any semantic segmentation. Therefore, building envelope images (e.g., walls and windows) were segmented based on a U-Net architecture compared to a more conventional semantic segmentation approach. The results were discussed to better understand the importance of the availability of training data and for scaling the workflow. Then, thermal anomaly thresholds for different target domains were detected using probability distributions. Finally, thermal anomaly masks of those domains were computed. This study conducted a comprehensive examination of a campus building in Syracuse, New York, utilizing a drone-based data collection approach. The case study successfully detected diverse thermal anomalies associated with various envelope components. The proposed approach offers the potential for immediate and accurate in situ thermal anomaly detection in building inspections. Full article

Soybean relies on symbiotic nitrogen fixation (SNF) to support sustainable agriculture. In this study, we conducted a comprehensive analysis of the GmMYB transcription factor subfamily 20, with a focus on GmMYB62a and GmMYB62b. Phylogenetic and structural analyses revealed that these genes are evolutionarily conserved among legumes and possess distinct domain architectures. Expression profiling and GUS staining showed that GmMYB62a and GmMYB62b are constitutively expressed in nodules. Functional analyses revealed that loss of GmMYB62s function significantly reduced nodule density, while overexpression promoted nodulation. Transcriptomic analysis (RNA-seq) further demonstrated that GmMYB62s regulate key pathways, including hormone signaling, immune responses, and cell wall metabolism, thereby coordinating symbiotic interactions. Collectively, our findings identify GmMYB62a and GmMYB62b as critical molecular regulators of nodulation in soybean, providing promising targets for improving symbiotic nitrogen fixation efficiency in legume crops. Full article

Carbon nanotubes (CNTs) have emerged as pivotal nanomaterials in sensing technologies owing to their unique structural, electrical, and mechanical properties. Their high aspect ratio, exceptional surface area, excellent electrical conductivity, and chemical tunability enable superior sensitivity and rapid response in various sensor platforms. This review presents a comprehensive overview of recent advancements in CNT-based sensors, encompassing both single-walled (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). We discuss their functional roles in diverse sensing applications, including gas sensing, chemical detection, biosensing, and pressure/strain monitoring. Particular emphasis is placed on the mechanisms of sensing, such as changes in electrical conductivity, surface adsorption phenomena, molecular recognition, and piezoresistive effects. Furthermore, we explore strategies for enhancing sensitivity and selectivity through surface functionalization, hybrid material integration, and nanostructuring. The manuscript also covers the challenges of reproducibility, selectivity, and scalability that hinder commercial deployment. In addition, emerging directions such as flexible and wearable CNT-based sensors, and their role in real-time environmental, biomedical, and structural health monitoring systems, are critically analyzed. By outlining both current progress and existing limitations, this review underscores the transformative potential of CNTs in the design of next-generation sensing technologies across interdisciplinary domains. Full article

Diblock copolymers (BCP) consisting of poly(methyl methacrylate) (PMMA) and poly(1H,1H,2H,2H-perfluorodecyl methacrylate) (PsfMA) blocks are employed as templates for controlled dispersion and localization of multi-walled carbon nanotubes (MWCNT). Short MWCNT are modified with perfluoroalkyl groups to increase the compatibility between MWCNT and the semifluorinated (PsfMA) phase and to promote a defined arrangement of MWCNT in the BCP morphology. Thin BCP and BCP/MWCNT composite films are prepared by dip-coating using tetrahydrofuran as solvent with dispersed MWCNT. Atomic force microscopy, scanning and transmission electron microscopy reveal a strong tendency of the BCP to form micelle-like domains consisting of a PMMA shell and a semifluorinated PsfMA core, embedded in a soft phase, containing also semifluorinated blocks. MWCNT preferentially localized in the embedding phase outside the micelles. Perfluoroalkyl-modification leads to significant improvement in the dispersion of MWCNT, both in the polymer solution and the resulting nanocomposite film due to increased interaction of MWCNT with the semifluorinated side chains in the soft phase outside the micelle domains. As a result, reliable electrical conductivity is observed in contrast to films with non-modified MWCNT. Thus, well-dispersed, modified MWCNT provide a defined electrical conduction path at the micrometer level, which is interesting for applications in electronics and vapor sensing. Full article

A well-designed clamping layout significantly enhances the dynamic stiffness of a manufacturing system, improving its stability and suppressing cutting chatter in workpieces. This paper focuses on the machining of thin-walled beams, which are prone to vibration and have low stiffness, especially under hydraulic floating clamping conditions. By analyzing the system stability domain, we propose a method to improve system stiffness through strategic design of support module layouts. Finite element dynamic simulations and modal hammer experiments were conducted to validate this approach. The results show that the proposed layout design method increases the relative central frequency by 13.49% and the relative fundamental frequency by 8.51%. These findings demonstrate a substantial improvement in the dynamic stiffness of the part-clamping system, confirming that the auxiliary support module layout design method effectively enhances system dynamic stiffness and suppresses cutting chatter. Full article

Wheat, a cold-tolerant crop, suffers substantial yield and quality losses under heat stress, yet the genetic mechanisms underlying thermotolerance remain understudied. We characterized TaCOBL6A2, a novel COBRA-like gene on wheat chromosome 6A encoding a glycosylphosphatidylinositol (GPI)-anchored protein with a conserved COBRA domain, and performed subcellular localization, tissue-specific expression, and stress response analyses to investigate its function. Functional validation was conducted based on TaCOBL6A2 overexpression in Arabidopsis and transcriptomic profiling. Additionally, a haplotype analysis of wheat varieties was performed to associate genotypes with heat stress phenotypes. The results show that TaCOBL6A2 is localized to the plasma membrane, the cell wall, and the nucleus, with the highest expression in early-stage grains. Its transcription was strongly induced by heat stress, exceeding that in response to cold, salt, or drought. Its overexpression in Arabidopsis enhanced thermotolerance and activated heat shock proteins (HSPs) and oxygen homeostasis pathways. The elite haplotype, Hap1, was associated with improved seedling growth and elevated antioxidant enzyme activity under heat stress. Our findings reveal that TaCOBL6A2 is a key regulator of wheat heat tolerance and could be used as a molecular target for breeding climate-resilient cultivars. Full article

The accurate prediction of the residual strength of defective pipelines is a critical prerequisite for ensuring the safe operation of oil and gas pipelines, and it holds significant implications for the pipeline’s remaining service life and preventive maintenance. Traditional machine learning algorithms often fail to comprehensively account for the correlative factors influencing the residual strength of defective pipelines, exhibit limited capability in extracting nonlinear features from data, and suffer from insufficient predictive accuracy. Furthermore, the predictive models typically lack interpretability. To address these issues, this study proposes a hybrid prediction model for the residual strength of defective pipelines based on Bayesian optimization (BO) and eXtreme Gradient Boosting (XGBoost). This approach resolves the issues of excessive iterations and high computational costs associated with conventional hyperparameter optimization methods, significantly enhancing the model’s predictive performance. The model’s prediction performance is evaluated using mainstream metrics such as the Mean Absolute Percentage Error (MAPE), Coefficient of Determination (R²), Root Mean Square Error (RMSE), robustness analysis, overfitting analysis, and grey relational analysis. To enhance the interpretability of the model’s predictions, reveal the significance of features, and confirm prior domain knowledge, Shapley additive explanations (SHAP) are employed to conduct the relevant research. The results indicate that, compared with Random Forest, LightGBM, Support Vector Machine, gradient boosting regression tree, and Multi-Layer Perceptron, the BO-XGBoost model exhibits the best prediction performance, with MAPE, R², and RMSE values of 5.5%, 0.971, and 1.263, respectively. Meanwhile, the proposed model demonstrates the highest robustness, the least tendency for overfitting, and the most significant grey relation degree value. SHAP analysis reveals that the factors influencing the residual strength of defective pipelines, ranked in descending order of importance, are defect depth (d), wall thickness (t), yield strength (σ_y), external diameter (D), defect length (L), tensile strength (σ_u), and defect width (w). The development of this model contributes to improving the integrity management of oil and gas pipelines and provides decision support for the intelligent management of defective pipelines in oil and gas fields. Full article

The goal of the present investigation is to explore the heater position and tilting angle of geometry on a buoyant convective stream and energy transport in a tilted, curved porous cavity. This work can be utilized in the field of solar panel construction and electrical equipment cooling. Since no study has explored the impact of the heater location in an inclined wavy porous chamber, three locations of the heater of finite length on the left sidewall, viz., the top, middle, and bottom, are explored. The stream through the porous material is explained by the Darcy model. The upper and lower walls, as well as the remaining area in the left wall, are covered with thermal insulation, while the curved right sidewall maintains the lower temperature. The governing equations and related boundary conditions are discretized by the finite difference approximations. The equations are then iteratively solved for different heater positions, inclinations, Darcy–Rayleigh number (Ra_D), and corrugation of the right walls. It is witnessed that the heater locations and cavity inclinations alter the stream and thermal fields within the curved porous domain. Furthermore, all heating zones benefit from improved heat conduction due to the right sidewall’s waviness and the tilted porous domain. Full article

The liquid-core anti-resonant fiber (LCARF) has emerged as a versatile platform for applications in nonlinear photonics, biological sensing, and other domains. In this study, a systematic and comprehensive analysis of LCARF was conducted via the finite element method to evaluate its performance across a wavelength range of 400–1200 nm. This included an assessment of the effects of structural parameters such as capillary wall thickness and the ratio of cladding tube diameter to core diameter on confinement loss and effective refractive index. The results reveal that the proposed core-only-filled approach significantly reduces the confinement loss compared to the conventional fully filled approach, thus facilitating signal transmission. Furthermore, the optimization of geometrical parameters greatly improves the single-mode characteristics of LCARFs. This work establishes a robust theoretical framework and provides valuable support for enhancing the LCARF applications in optofluidics, thereby contributing to the evolution of specialty fiber technologies. Full article

The Free Double-Piston Composite Cycle Engine (FDP-CCE) integrates the turbofan engine architecture with the characteristics of piston engines with the aim of improving engine efficiency and decreasing CO₂ emissions. The FDP-CCE features a free-piston design, providing a lighter and more compact structure compared to conventional crankshaft-connected piston engines due to the elimination of mechanical transmissions and lubrication systems. Innovations like air lubrication and increased piston velocities contribute to higher cylinder temperatures, underscoring the need for advanced thermal management strategies. For this reason, in the present work, a heat transfer model to address the thermal management challenges in this innovative engine design is developed. More specifically, a novel filling–discharge model for a two-stroke compression ignition engine is developed, dividing the operational cycle into phases handled by the piston engine and the piston compressor. Special emphasis is given to the implementation of various geometric zones for each piston to optimize the heat transfer between the combustion chamber and the cylinder walls and heads. The final step of this research work involves the integration of piston temperatures into the boundary conditions of an equivalent computational domain to conduct a detailed heat transfer and fluid flow analysis around and on the FDP cylinder. By focusing on these critical aspects, this study establishes a fundamental framework for future aeroengine designs, promoting sustainable propulsion solutions with reduced fuel consumption and emissions. Full article

Research on phononic crystals with negative refractive indices constitutes the most crucial approach to achieving ultra-high-resolution acoustic lenses. This study presents a glide-reflection (GR) symmetrical phononic crystal (PC), and the mismatch of the Wannier center between two PCs leads to the emergence of edge states (ESs). By constructing a single-domain wall, the negative refraction is achieved due to the excitation of ESs with negative dispersion. Further, by stacking multiple GR symmetric PC interfaces, the coupled edge states (CESs) are found, which originate from the coupling between the adjacent interfaces. Thus, stronger negative sound refraction effects with negative transverse displacement can be achieved, because the incident sound wave can be coupled into the CESs with negative dispersion. Simulation results are conducted using the finite element method to verify our idea, and our research provides a novel methodology for the design of acoustic negative refraction. Full article

Background: Casein kinase I protein Hrr25 plays important roles in many cellular processes, including autophagy, vesicular trafficking, ribosome biogenesis, mitochondrial biogenesis, and the DNA damage response in Saccharomyces cerevisiae. Pin4 is a multi-phosphorylated protein that has been reported to be involved in the cell wall integrity (CWI) pathway and DNA damage response. Pin4 was reported to interact with Hrr25 in yeast two-hybrid and large-scale pulldown assays. Methods/Objectives: Co-immunoprecipitation and yeast two-hybrid assays were utilized to confirm whether Pin4 and Hrr25 interact and to determine how they interact. Genetic interaction analysis was conducted to examine whether hrr25 mutations form synthetic growth defects with mutations in genes involved in CWI signaling. Immunoblotting was used to determine whether Hrr25 phosphorylates Pin4. Results: We show that Hrr25 interacts with Pin4 and is required for Pin4 phosphorylation. pin4 mutations result in synthetic slow-growth phenotypes with mutations in genes encoding Bck1 and Slt2, two of the protein kinases in the MAP kinase cascade that regulates CWI in the budding yeast. We show that hrr25 mutations result in similar phenotypes to pin4 mutations. Hrr25 consists of an N-terminal kinase domain, a middle region, and a C-terminal proline/glutamine-rich domain. The function of the C-terminal P/Q-rich domain of Hrr25 has been elusive. We found that the C-terminal region of Hrr25 is required both for Pin4 interaction and CWI. Conclusions: Our data suggest that Hrr25 is implicated in cell wall integrity signaling via its association with Pin4. Full article

Background/Objectives: Clostridioides difficile is a Gram-positive, spore-forming enteric pathogen that causes intestinal disorders, including inflammation and diarrhea, primarily through toxin production. Standard treatment options for C. difficile infection (CDI) involve a limited selection of antibiotics that are not fully effective, leading to high recurrence rates. Vaccination presents a promising strategy for preventing both CDI and its recurrence. Cell wall protein 2 (Cwp2), a highly immunogenic and abundant surface-exposed C. difficile cell wall protein, plays an important role in the bacterium’s adherence in vitro. In this study, we aimed to analyze the homology and immunogenicity of Cwp2 and its protection efficacy as a vaccine candidate against CDI in mice. Methods: we conducted in silico analyses to assess the homology and immunogenicity of Cwp2, and we evaluated its potential as a vaccine candidate against CDI using a mouse model of immunization and infection. Results: Our in silico analyses predicted the immunogenic region (functional domain) of Cwp2 and revealed its high homology among various toxinotypes and ribotypes (R.T.s) or sequence types (S.T.s). Immunizations of mice with the Cwp2 functional domain (Cwp2_A) induced potent IgG/A antibody responses against Cwp2_A, protected mice from CDI, and reduced C. difficile spore and toxin levels in feces post-infection. Additionally, anti-Cwp2_A sera inhibited the binding of C. difficile vegetative cells to HCT8 cells. Conclusions: Our report demonstrates for the first time the potential of Cwp2_A as an effective vaccine candidate against CDI in mice. Full article

The characterization of the lunar surface and subsurface through the utilization of synthetic aperture radar data has assumed a pivotal role in the domain of lunar exploration science. This investigation concentrated on the polarimetric analysis aimed at identifying water ice within a specific crater, designated Erlanger, located at the lunar north pole, which is fundamentally a region that is perpetually shaded from solar illumination. The area that is perpetually shaded on the moon is defined as that region that is never exposed to sunlight due to the moon’s slightly tilted rotational axis. These permanently shaded regions serve as cold traps for water molecules. To ascertain the presence of water ice within the designated study area, we conducted an analysis of two datasets from the Chandrayaan mission: Mini-SAR data from Chandrayaan-1 and Dual-Frequency Synthetic Aperture Radar (DFSAR) data from Chandrayaan-2. The polarimetric analysis of the Erlanger Crater, located in a permanently shadowed region of the lunar north pole, utilizes data from the Dual-Frequency Synthetic Aperture Radar (DFSAR) and the Mini-SAR. This study focuses exclusively on the L-band DFSAR data due to the unavailability of S-band data for the Erlanger Crater. The crater, identified by the PSR ID NP_869610_0287570, is of particular interest for its potential water ice deposits. The analysis employs three decomposition models—m-delta, m-chi, and m-alpha—derived from the Mini-SAR data, along with the H-A-Alpha model known as an Eigenvector and Eigenvalue model, applied to the DFSAR data. The H-A-Alpha helps in assessing the entropy and anisotropy of the lunar surface. The results reveal a correlation between the hybrid polarimetric models (m-delta, m-chi, and m-alpha) and fully polarimetric parameters (entropy, anisotropy, and alpha), suggesting that volume scattering predominates inside the crater walls, while surface and double bounce scattering are more prevalent in the right side of the crater wall and surrounding areas. Additionally, the analysis of the circular polarization ratio (CPR) from both datasets suggests the presence of water ice within and around the crater, as values greater than 1 were observed. This finding aligns with other studies indicating that the high CPR values are indicative of ice deposits in the lunar polar regions. The polarimetric analysis of the Erlanger Crater contributes to the understanding of lunar polar regions and highlights the potential for future exploration and resource utilization on the Moon. Full article