Search Results (40,692)

Historic Building Information Modelling (HBIM) is the application of BIM, a digital information management and 3D modelling technique, to cultural heritage (CH) assets. It will assist with the ongoing sustainable management of CH in line with the United Nations’ Sustainable Development Goals (i.e., SDG 11 and SDG 13) by providing an enduring record of asset information and enabling the energy-efficient use and adaption of assets. However, the application of HBIM is currently limited by a lack of defined end-user requirements and standard methodology in its application. This paper is the second piece in a series of works where the authors adopted a systems thinking approach, utilising both the Soft Systems Methodology (SSM) and hard systems engineering (SE), for the development of HBIM. This paper presents the results of an extensive survey undertaken with the UK Heritage Community. It validates forty-one previously proposed information requirements, identifies a further twenty new information requirements for HBIM, and utilises the SE process to define thirty-three system requirements for HBIM according to the end user. Full article

Background: Cardiovascular diseases are the leading cause of morbidity and mortality among diabetic patients, with their incidence rising globally. Streptozotocin (STZ)-induced diabetic rats, untreated with insulin, exhibit human-like symptoms such as hyperglycemia, polydipsia, polyuria, weight loss, cardiomyopathy, neuropathy, and oxidative stress. Thus, this study evaluated the effects of Ilex guayusa tea on cardiovascular, autonomic, metabolic, and oxidative stress parameters in diabetic rats, as well as its antioxidant and phytochemical properties. Methods: Thirteen female Wistar rats were divided into two groups: diabetic (D; n = 7) and diabetic + Ilex guayusa (DG; n = 6). Diabetes was induced by a single STZ injection (50 mg/kg, i.v.), and guayusa tea was provided ad libitum for 21 days (3.0 g/L). Results: Glycemia and body mass were initially similar between the groups; however, throughout the protocol, the D group showed an increase in glycaemia and a decrease in body mass when compared to initial values. While no differences in arterial pressure, heart rate, linear heart rate variability, and oxidative stress were observed, the D group showed reduced vascular sympathetic modulation (LF-SAP and VAR-SAP) compared to the DG group. This reduced vascular sympathetic modulation, which was a poor prognostic marker in this model, was inversely correlated with glycemia (VAR-SAP and final glycemia, r: −0.81, p = 0.002). Conclusions: These findings suggest that Ilex guayusa tea consumption may mitigate metabolic and autonomic dysfunction in diabetes, highlighting its potential therapeutic role in managing diabetic complications. Full article

Timber construction experiences a growing trend in different countries due to its inherent environmental benefits and proven lateral load performance. However, most of the previous studies on structural and seismic performance have focused on undamaged structures without any signs of deterioration. This paper focuses on the analysis of the effects of the initial damage state on the seismic response and fragility of a five-story CLT building designed under a force-based approach. A detailed 3D finite element model was developed and validated through experimental data in order to perform incremental dynamic analyses that considered different arbitrarily imposed initial damage states. The residual response and the fragility functions are analyzed to characterize the impact of the initial state on seismic behavior. The results of this work highlight the need to properly consider the effect of previous load actions for the seismic performance evaluation during the operating life of CLT structures. Findings suggest that the initial state can significantly modify the probability of reaching a given limit state. Moreover, it was found that if the initial damage is defined as severe, the collapse margin ratio is reduced by 58.8% compared to the case in which the initial state is undamaged. Full article

This paper introduces a novel chaotic finance system derived by incorporating a modeling uncertainty with an absolute function nonlinearity into existing financial systems. The new system, based on the works of Gao and Ma, and Vaidyanathan et al., demonstrates enhanced chaotic behavior with a maximal Lyapunov exponent (MLE) of 0.1355 and a fractal Lyapunov dimension of 2.3197. These values surpass those of the Gao-Ma system (MLE = 0.0904, Lyapunov dimension = 2.2296) and the Vaidyanathan system (MLE = 0.1266, Lyapunov dimension = 2.2997), signifying greater complexity and unpredictability. Through parameter analysis, the system transitions between periodic and chaotic regimes, as confirmed by bifurcation diagrams and Lyapunov exponent spectra. Furthermore, multistability is demonstrated with coexisting chaotic attractors for p = 0.442 and periodic attractors for p = 0.48. The effects of offset boosting control are explored, with attractor positions adjustable by varying a control parameter k, enabling transitions between bipolar and unipolar chaotic signals. These findings underline the system’s potential for advanced applications in secure communications and engineering, providing a deeper understanding of chaotic finance models. Full article

This paper presents an efficient and compact MATLAB code for 3D topology optimization of multi-materials. The multi-material problem using a mapping-based material interpolation function is adopted from previous work, in which each material is modeled in the same way, presenting a clear (clean) result of 0 and 1 for each material of the optimized structures, without gray elements, thus facilitating the manufacturing process. A new projection function, the sigmoid function, is adopted for the filtered design variables for each material in the domain. The proposed method improves computational efficiency, reducing computational costs by up to 36.7%, while achieving a 19.1% improvement in the objective function compared to the hyperbolic tangent function. A multi-material topology optimization solution with minimal compliance under volume constraints, including details of the optimization model, filtering, projection, and sensitivity analysis procedures, is presented. Numerical examples are also used to demonstrate the effectiveness of the code, and the influence of the position of the support on the optimized results is also proven. The complete MATLAB code for 3D elastic structures is presented as an example. Full article

The rapid growth in the use of wind energy has led to significant challenges in the inspection and maintenance of wind turbine blades, especially as turbine sizes increase dramatically and as operational environments become harsh and unpredictable. Wind turbine blades, being the most expensive and failure-prone components, directly affect operational stability and energy efficiency. The efficient and precise inspection of these blades is therefore essential to ensuring the sustainability and reliability of wind energy production. To overcome the limitations of the existing inspection methods, which suffer from low detection precision and inefficiency, this paper proposes a novel complete coverage path planning (CCPP) algorithm for wall-climbing robots operating on wind turbine blades. The proposed algorithm specifically targets highly complex regions with significant curvature variations, utilizing 3D point cloud data to extract height information for the construction of a 2.5D grid map. By developing a tailored energy consumption model based on diverse robot motion modes, the algorithm is integrated with a bio-inspired neural network (BINN) to ensure optimal energy efficiency. Through extensive simulations, we demonstrate that our approach outperforms the traditional BINN algorithms, achieving significantly superior efficiency and reduced energy consumption. Finally, experiments conducted on both a robot prototype and a wind turbine blade platform validate the algorithm’s practicality and effectiveness, showcasing its potential for real-world applications in large-scale wind turbine inspection. Full article

The acoustic emissions of ventilation systems and their subcomponents contribute to the perceived overall comfort in indoor environments and are, therefore, the subject of research. In contrast to fans, there is little research on the aeroacoustic properties of air diffusers (often referred to as outlets). This study investigates a commercially available ceiling swirl diffuser. Using a hybrid approach, a detailed three-dimensional large-eddy simulation is coupled with a perturbed wave equation to capture the aeroacoustic processes within the diffuser. The flow model is validated for the investigated operating point of 470 ${\mathrm{m}}^3$/$\mathrm{h}$ using laser-optical and acoustic measurements. To identify the noise sources, the acoustic pressure is sampled with various receivers and on cut sections to evaluate the cross-power spectral density, and the sound-pressure level distribution on cut sections is evaluated. It is found that the plenum attenuates the noise near its acoustic eigenmodes and thus dominates other noise sources by several orders of magnitude. By implementing the plenum walls as sound-absorbing, the overall sound-pressure level is predicted to decrease by nearly 10 dB/Hz. Other relevant geometric features are the mounting beam and the guide elements, which are responsible for flow-borne noise emissions near 698 Hz and 2699 Hz, respectively. Full article

Background: Metastable zone width (MSZW) and solubility are crucial for developing crystallization procedures in the purification of active pharmaceutical ingredients (APIs). Traditionally, determining these properties involves labor-intensive methods that can take weeks or even months. With advancements in process analytical technologies (PAT) and the increasing focus on quality by design (QbD) in pharmaceutical manufacturing, more efficient and reliable protocols are needed. In this study, we employ in situ Fourier Transform Infrared (FTIR) spectroscopy and Focused Beam Reflectance Measurement (FBRM) to establish protocols for measuring solubility at different temperatures and MSZW at varying cooling rates. Methods: We experimentally determined MSZW and solubility using FTIR spectroscopy and FBRM. IR spectra were analyzed to obtain solubility concentrations, while FBRM counts were used to extract MSZW and supersolubility concentrations. The collected data were assessed using four theoretical models, including a newly developed model based on classical nucleation theory. By fitting experimental MSZW data to these models, we determined nucleation kinetics and thermodynamic parameters. Results: Our novel model exhibited excellent agreement with experimental MSZW data across different cooling rates, demonstrating its robustness. The nucleation rate constant and nucleation rate ranged between 10²¹ and 10²² molecules/m³·s. The Gibbs free energy of nucleation was calculated as 3.6 kJ/mol, with surface energy values between 2.6 and 8.8 mJ/m². The estimated critical nucleus radius was in the order of 10⁻³ m. Conclusions: The protocols we developed for predicting MSZW and solubility of paracetamol using PAT can serve as a guideline for other APIs. Our theoretical model enhances the predictive accuracy of nucleation kinetics and thermodynamics, contributing to optimized crystallization processes. Full article

Shape-memory polymer nanocomposites (SMPNCs) have emerged as a transformative class of smart materials, combining the versatility of shape-memory polymers (SMPs) with the enhanced properties imparted by nanostructures. Integrating these nanofillers, this review explores the pivotal role of SMPNCs in addressing critical limitations of traditional SMPs, including low tensile strength, restricted actuation modes, and limited recovery stress. It comprehensively examines the integration of nanofillers, such as nanoparticles, nanotubes, and nanofibers, which augment mechanical robustness, thermal conductivity, and shape-recovery performance. It also consolidates foundational knowledge of SMPNCs, covering the principles of the shape-memory phenomenon, fabrication techniques, shape-recovery mechanisms, modeling approaches, and actuation methods, with an emphasis on the structural parameters of nanofillers and their interactions with polymer matrices. Additionally, the transformative real-world applications of SMPNCs are also highlighted, including their roles in minimally invasive medical devices, adaptive automotive systems, 4D printing, wearable electronics, and soft robotics. By providing a systematic overview of SMPNC development and applications, this review aims to serve as a comprehensive resource for scientists, engineers, and practitioners, offering a detailed roadmap for advancing smart materials and unlocking the vast potential of SMPNCs across various industries in the future. Full article

Ear reconstruction surgeries for congenital deformities and trauma are common, highlighting the need for improved cartilage regeneration. Lactoferrin (LF), a natural and cost-effective protein, is promising due to its anti-inflammatory, antimicrobial, and prochondrogenic properties. This study investigates the effects of LF on the viability, proliferation, and chondrogenesis of rabbit auricular chondrocytes. For in vitro studies, auricular chondrocytes were cultured for three passages, after which 3D pellets were formed. LF significantly increased chondrocyte metabolic activity by 1.5 times at doses of 10 and 500 μg/mL. At passage 3, LF at concentrations of 10 and 100 μg/mL increased cell proliferation rates by 2- and 1.5-fold, respectively. Immunohistochemical staining of the pellets demonstrated that LF at 10 μg/mL increased the amount of sex-determining region Y-Box Transcription Factor 9 (Sox9)+ cells by 30%, while at 100 μg/mL, it doubled the type II collagen deposits. For in vivo studies, a rabbit ear defect model was utilized. On post-operative day 60, the LF-treated group exhibited more mature cartilage regeneration, with a higher density of elastic fibers. By day 90 post-surgery, LF application led to the restoration of normal elastic cartilage throughout the defect. These findings suggest that LF promotes auricular chondrocytes chondrogenesis and could be beneficial for tissue engineering of the elastic cartilage. Full article

Forests, as a critical component of terrestrial ecosystems, have long been recognized for their vital roles as water, money, grain, and carbon repositories, collectively known as the “Four Repositories” concept. The significance of forests in the context of economic and ecological development has become increasingly prominent. As a novel economic paradigm and a new driver of growth, the digital economy ($DIG$) can significantly improve the management, operation, and preservation of forests, thus offering new prospects for advancing the high-quality development of forestry ($HQDF$) in China. This study constructs indicator systems for the levels of $HQDF$ and $DIG$ using panel data from 30 provinces in China over the period from 2012 to 2021. The empirical analysis utilizes a fixed effect model to assess the influence of $DIG$ in promoting $HQDF$ in China. Moreover, the mediation analysis model is employed to examine the underlying mechanisms. There are four main results as follows. First, the baseline regression results show that $DIG$ can directly drive $HQDF$ in China. Second, the mechanism analysis reveals that $DIG$ positively influences $HQDF$ through three mediating channels: strengthening environmental regulation, enhancing public environmental awareness, and increasing innovation in forestry. Third, the heterogeneity analysis indicates that the positive impact of $DIG$ on $HQDF$ is more pronounced in northern provinces, economically advanced regions, and provinces with stronger fiscal support for forestry. Fourth, further analysis reveals significant spatial spillover effects of $DIG$ on $HQDF$ in China. The study findings not only clarify the driving mechanisms of $DIG$ in $HQDF$, but also provide valuable policy insights for exploring practical pathways for $HQDF$ in China in the modern context. Full article

Sanitary landfill covers are exposed to varying environmental conditions; hence, the state of the clay layer also changes from saturated to unsaturated. The study aimed to predict the unsaturated hydraulic conductivity of the locally available compacted clay and clay with polyurethane to determine their behavior as they change from wet to dry using matric suction and empirical models proposed through other studies. The specimens underwent three wet–dry cycles wherein the matric suction was determined for several moisture content levels as the specimen dried using the filter paper method or ASTM D5298. The results showed that the factors affecting the soil structure, such as grain size difference between clay and polyurethane–clay, varying initial void ratios, and degradation of the soil structure due to the wet–dry cycles, did not affect the matric suction at the higher suction range; however, these factors had an effect at the lower suction range. The matric suction obtained was then used to establish the best fit water retention curve (WRC) or the relationship between the matric suction and moisture content. The WRC was used to predict the unsaturated hydraulic conductivity and observe the soil–water interaction. The study also observed that the predicted unsaturated hydraulic conductivity decreases as the compacted specimen moves to a drier state. Full article

In recent decades, the condition of many bridge structures has deteriorated and the need for maintenance measures has increased. Until now, these maintenance measures have mainly been carried out manually and reactively. The use of digital 3D models based on Building Information Modelling (BIM) can remedy this situation and create the basis for predictive maintenance management. While the generation of 3D models of new bridge structures is simple, the digitization of existing structures can be a complex process. This article provides an overview of the state of the scientific practice with regard to the procedures, technologies and data used to generate 3D models of existing bridge structures using the BIM method. Using a systematic literature analysis, scientific databases are searched for suitable literature and analysed with predefined filtering parameters. The results provide a uniform understanding of the current status quo of the digitisation of existing bridge structures and show existing degrees of digitisation and automation. Full article

Coal gangue slurry filling technology is an effective way of utilizing coal gangue solid waste resources rationally, and its fluidity and sedimentation behavior have an essential influence on filling performance. However, evaluation and optimization methods for the fluidity and sedimentation performance of coal gangue slurry filling materials (CSFMs) are still scarce. In order to solve this problem, based on the fractal grading theory, this paper carried out an experimental study on the influence of the fractal dimension on the flow characteristics of CSFMs, revealed the impact of the fractal dimension on the flow performance of slurry, and constructed a CSFM flow performance evaluation and optimization model based on the fractal dimension. At the same time, the influence of the fractal dimension on solid mass fraction and particle distribution in the CSFM sedimentation process was analyzed using a sedimentation experiment. Combined with fitting analysis and model construction, a CSFM sedimentation performance evaluation method based on fractal dimension D was proposed. The results show that (1) the slump, expansion, and yield stress of CSFMs increased first and then decreased with the increase in the fractal dimension, and the bleeding rate of CSFMs decreased with the rise in the fractal dimension. The analysis of the consistency coefficient of CSFMs shows that the increase in the proportion of fine particles will increase the consistency coefficient. (2) The fitting analysis indicates that the fractal dimension D of CSFMs is negatively correlated with the sedimentation performance P_S. The change in D is most significant in the range of 2.3 to 2.4, where the slurry’s stability is poor. When D exceeds 2.5, the slurry’s stability improves significantly. (3) Based on the evaluation of flow performance and settlement performance, the flow performance and settlement performance of CSFMs with fractal dimensions between 2.50 and 2.59 achieve the best balance, which ensures the reliability of long-distance transportation and construction quality. The research results can provide a reference for the pipeline transportation of whole gangue slurry and have important practical significance for realizing the large-scale disposal of gangue solid waste and green mining of coal mines. Full article

The deconstruction of a building marks the end of its life cycle. At the same time, this phase offers many opportunities for the acquisition and reuse of used building materials. During the deconstruction phase, planning and execution are carried out using a variety of different software applications. Despite the use of digital 3D models according to the Building Information Modeling (BIM) method, there is no interoperability along the value chain in the deconstruction of a building. To counteract the lack of interoperability in the deconstruction phase of buildings, the article develops an ontology for the formalization of knowledge within the deconstruction phase and the usability of heterogeneous data sets in connection with the 3D BIM model. After assessing the status quo on the topic of BIM in deconstruction and ontologies in building construction, the systematic development of the deconstruction ontology (DCO) and its validation on a demonstrator is conducted. The result is the presentation of the basic usability of ontologies in conjunction with graphical databases and digital 3D models in the deconstruction phase. This ensures interoperability along the value chain and counteracts data loss. Full article