Mechanical Aspects Research Articles

Comprehensive Multidisciplinary Electric Vehicle Modeling: Investigating the Effect of Vehicle Design on Energy Consumption and Efficiency

In this study, an electric vehicle (EV) dynamic model is devised that amalgamates mechanical design aspects—such as aerodynamic effects, tire friction, and vehicle frontal area—with crucial components of the electrical infrastructure, including the electric motor, power converters, and battery systems. Verification of the model is executed through a comprehensive multidisciplinary analysis utilizing CATIA, ANSYS Electromagnetics, ANSYS Fluent, and MATLAB–Simulink tools, which are applied to evaluate two alternative lightweight EV prototypes. The process involves initial computations of critical inputs for the dynamic model, including aerodynamic lift (C1), drag coefficients (Cd), and frontal area (Af). Subsequent stages entail the detailed design and analysis of a 2 kW brushless permanent magnet electric motor in ANSYS Electromagnetics to map efficiency contours across various speed–torque values. Integration of these parameters into a MATLAB–Simulink dynamic model, connected with motor drive inverter and battery models, allows for simulation-based energy consumption analysis under race track slope profiles. Remarkably, the findings underscore the considerable impact of neglected parameters on energy consumption, often exceeding fifty percent of the total. Consequently, an energy-efficient EV prototype is manufactured and rigorously tested under specified drive conditions, affirming the validation of the comprehensive multidisciplinary EV dynamic model.

Obesity, Metabolic Syndrome, and Osteoarthritis Require Integrative Understanding and Management.

Osteoarthritis (OA) is a progressive chronic disease affecting the articular joints, leading to pain and disability. Unlike traditional views that primarily link OA to aging, recent understanding portrays it as a multifactorial degenerative disease of the entire joint. Emerging research highlights metabolic and immune dysregulation in OA pathogenesis, emphasizing the roles of obesity, dyslipidemia, and insulin resistance in altering joint homeostasis. Recent studies have increasingly focused on the complex role of white adipose tissue (WAT) in OA. WAT not only serves metabolic functions but also plays a critical role in systemic inflammation through the release of various adipokines. These adipokines, including leptin and adiponectin, have been implicated in exacerbating cartilage erosion and promoting inflammatory pathways within joint tissues. The overlapping global crises of obesity and metabolic syndrome have significantly impacted joint health. Obesity, now understood to contribute to mechanical joint overload and metabolic dysregulation, heightens the risk of developing OA, particularly in the knee. Metabolic syndrome compounds these risks by inducing chronic inflammation and altering macrophage activity within the joints. The multifaceted effects of obesity and metabolic syndrome extend beyond simple joint loading. These conditions disrupt normal joint function by modifying tissue composition, promoting inflammatory macrophage polarization, and impairing chondrocyte metabolism. These changes contribute to OA progression, highlighting the need for targeted therapeutic strategies that address both the mechanical and biochemical aspects of the disease. Recent advances in understanding the molecular pathways involved in OA suggest potential therapeutic targets. Interventions that modulate macrophage polarization, improve chondrocyte function, or normalize adipokine levels could serve as preventative or disease-modifying therapies. Exploring the role of diet, exercise, and pharmacological interventions in modulating these pathways offers promising avenues for reducing the burden of OA. Furthermore, such methods could prove cost-effective, avoiding the increase in access to healthcare.

Progress and challenges in designing dynamic in vitro gastric models to study food digestion.

Understanding the mechanisms involved in food breakdown in the human gastrointestinal (GI) tract is essential in food digestion research. Research to study food digestion in the human GI tract requires in vivo and in vitro approaches. In vivo methods involving human or animal subjects are often cost-prohibitive and raise ethical concerns. For these reasons, in vitro approaches are becoming more common. Several dynamic in vitro models that mimic one or more components of the GI tract have been developed at various research institutions and by commercial companies. While there is evidence of considerable novelty and innovation in the design of these models, there are many differences among them in how the mechanical breakdown of solid foods is accomplished. In some systems, modulating water pressure is used to achieve peristaltic contractions of the gastric antrum, whereas, in other models, the flexible walls of a gastric chamber are compressed by the movement of rollers or clamps outside the walls of the test chamber. Although much progress has been made in standardizing the biochemical environment appropriate to the food digestion process, there is a lack of standard protocols to measure mechanical forces that result in the breakdown of solid foods. Similarly, no standardized methods are available to evaluate the results obtained from in vitro trials for validation purposes. Due to the large variability in the design features of in vitro models used for food digestion studies, developing consensus-based standards for the mechanical aspects of food breakdown is needed.

The mechanochemistry of lanthanum dihydride (LaH\(_{2}\)) with hydrogen (H\(_{2}\)) using the ball-mill process and the effect of oxidation on the resulting products

The complex behavior of LaH2 during ball milling was investigated in this study, with its mechanical, chemical, and morphological changes explored. The relationship between milling time and hydrogen pressure reduction was uncovered through detailed experiments, reflecting the dynamic nature of the process. A transient yet significant event was observed upon unsealing the milling jar post-milling: the emergence of a minor fire ember, indicative of the interplay between mechanical forces and chemical reactivity within the LaH2 powder. Profound changes in the structure, composition, and shape were unraveled using advanced techniques such as X-ray diffraction (XRD), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM/EDX), and particle size distribution analysis. The resulting powder exhibited a dual-phase composition of lanthanum dihydride (LaH2, 68.1% to 71.5%) and lanthanum oxide (La2O3, 28.5% to 31.9%), reflecting a dynamic chemical equilibrium during milling. Particle size distribution analysis revealed a notable increase in average diameter to 6420 nm, accompanied by a polydispersity index (PDI) of 0.831, signifying a broadening compared to the initial LaH2 powder. The morphological evolution of the powder was elucidated through SEM imaging, showing predominantly spherical and rounded forms, indicating extensive particle agglomeration and plastic deformation during milling. Additionally, the formation of oxide layers on the powder surface, intertwined with pronounced particle agglomeration, was highlighted through EDX mapping, shedding light on the mechanical aspects of morphological evolution during milling. These findings contribute to our understanding of LaH2 behavior under extreme mechanical and chemical conditions and have implications for materials processing, hydrogen storage technologies, and broader applications in materials science and engineering.

Feasibility exploration of GSH in the treatment of acute hepatic encephalopathy from the aspects of pharmacokinetics, pharmacodynamics, and mechanism.

Our previous study highlighted the therapeutic potential of glutathione (GSH), an intracellular thiol tripeptide ubiquitous in mammalian tissues, in mitigating hepatic and cerebral damage. Building on this premise, we posited the hypothesis that GSH could be a promising candidate for treating acute hepatic encephalopathy (AHE). To verify this conjecture, we systematically investigated the feasibility of GSH as a therapeutic agent for AHE through comprehensive pharmacokinetic, pharmacodynamic, and mechanistic studies using a thioacetamide-induced AHE rat model. Our pharmacodynamic data demonstrated that oral GSH could significantly improve behavioral scores and reduce hepatic damage of AHE rats by regulating intrahepatic ALT, AST, inflammatory factors, and homeostasis of amino acids. Additionally, oral GSH demonstrated neuroprotective effects by alleviating the accumulation of intracerebral glutamine, down-regulating glutamine synthetase, and reducing taurine exposure. Pharmacokinetic studies suggested that AHE modeling led to significant decrease in hepatic and cerebral exposure of GSH and cysteine. However, oral GSH greatly enhanced the intrahepatic and intracortical GSH and CYS in AHE rats. Given the pivotal roles of CYS and GSH in maintaining redox homeostasis, we investigated the interplay between oxidative stress and pathogenesis/treatment of AHE. Our data revealed that GSH administration significantly relieved oxidative stress levels caused by AHE modeling via down-regulating the expression of NADPH oxidase 4 (NOX4) and NF-κB P65. Importantly, our findings further suggested that GSH administration significantly regulated the excessive endoplasmic reticulum (ER) stress caused by AHE modeling through the iNOS/ATF4/Ddit3 pathway. In summary, our study uncovered that exogenous GSH could stabilize intracerebral GSH and CYS levels to act on brain oxidative and ER stress, which have great significance for revealing the therapeutic effect of GSH on AHE and promoting its further development and clinical application.

How cytoskeletal crosstalk makes cells move: Bridging cell-free and cell studies.

Cell migration is a fundamental process for life and is highly dependent on the dynamical and mechanical properties of the cytoskeleton. Intensive physical and biochemical crosstalk among actin, microtubules, and intermediate filaments ensures their coordination to facilitate and enable migration. In this review, we discuss the different mechanical aspects that govern cell migration and provide, for each mechanical aspect, a novel perspective by juxtaposing two complementary approaches to the biophysical study of cytoskeletal crosstalk: live-cell studies (often referred to as top-down studies) and cell-free studies (often referred to as bottom-up studies). We summarize the main findings from both experimental approaches, and we provide our perspective on bridging the two perspectives to address the open questions of how cytoskeletal crosstalk governs cell migration and makes cells move.

Short-term plasticity as 'energetic memory' of ion channel components of action potential.

Information transfer in the nervous system is traditionally understood by the transmission of action potentials along neuronal dendrites, with ion channels in the membrane as the basic unit operator for their creation and propagation. We present here a new model for the multiphysics behaviour of ion channels and the action potential dynamics in nervous and other signal-transmitting systems. This model is based on the long-term suppression of an action potential as a response to mechanical input. While other models focus on electrical aspects of the action potential, an increasing body of experiments highlights its electro-mechanical nature and points in particular towards an alteration of the action potential when subjected to a mechanical input. Here, we propose a new phenomenological framework able to capture the mechanical aspect of ion channel dynamics and the resulting effect on the overall electrophysiology of the membrane. The model is introduced here through a set of coupled differential equations that describe the system while agreeing with the general findings of the experiments that support an electro-mechanical model. It also confirms that transient quasi-static mechanical loads reversibly affect the amplitude and rate of change of neuronal action potentials, which are smaller and slower under indentation loading conditions. Changes after the loading release are also reversible, albeit on a different time scale.

Design and performance simulation of a silica microdisk cavity optical pressure sensor

The opto-mechanical system of optical whispering-gallery mode (WGM) microcavities confines resonant photons in micro-scale resonators for a long time, which can strongly enhance the interaction between light and matter, making it an ideal platform for various sensors. To measure the slim optical pressure in the interaction between the laser and matter, a silica microdisk cavity sensor with metal film is designed in this paper. In this study, the finite element method was employed to investigate the opto-mechanical coupling mechanism in a microdisk cavity. From the aspects of optics and mechanics, the structural parameters of the sensor were optimized and the performance was simulated. The simulation results show that at 1550 nm, the sensor’s optical quality factor (Q) can reach ∼104, the free spectral range is ∼5.3nm, the sensing sensitivity is 5.32mPa/Hz1/2, and the optical force resolution is 6.61×10−12N, which is better than the thin-film interferometry and optical lever method.

A Rapid Review on Complaint Mechanisms for Interpersonal Violence: Integrating Research-Based Recommendations from Multiple Sectors to Inform Sport Settings.

Past studies have highlighted the lack of independent formal complaint mechanisms as one of the most significant barriers to reporting interpersonal violence (IV) in sport. Some countries have since implemented complaint mechanisms specific to sport settings. Evaluations of similar mechanisms in other sectors could inform the development and implementation of complaint mechanisms for IV in sport. This rapid review included studies inside and outside the sport context to document the characteristics of complaint mechanisms of IV, barriers or limitations related to such mechanisms, and recommendations resulting from their evaluation. Following the Cochrane Rapid Reviews Interim Guidance, six databases were searched for peer-reviewed references in English or French, published between 2012 and 2022, and pertaining to the evaluation of formal reporting mechanisms of IV. The 35 references covered mechanisms mainly targeting IV in general (any type) or sexual violence specifically. Complaint mechanisms varied in scope and as a function of their setting, including work, university, military, and medical. We identified barriers and limitations concerning fear of consequences, lack of knowledge, lack of efficiency, lack of trust, and unsupportive culture. Finally, we documented 18 recommendations to improve complaint mechanisms of IV, spanning four categories: (a) organizational accountability, (b) awareness and accessibility, (c) adapted process, and (d) ongoing evaluation. This rapid review draws recommendations from various research disciplines and types of mechanisms to offer a comprehensive portrait of best practices. The findings show that numerous aspects of complaint mechanisms at multiple levels should be considered when developing and implementing complaint mechanisms of IV.

Accounting for quantum effects in atomistic spin dynamics

Atomistic spin dynamics (ASD) is a standard tool to model the magnetization dynamics of a variety of materials. The fundamental dynamical model underlying ASD is entirely classical. In this paper, we present two approaches to effectively incorporate quantum effects into ASD simulations, thus enhancing their low-temperature predictions. The first allows to simulate the magnetic behavior of a quantum spin system by solving the equations of motion of a classical spin system at an effective temperature relative to the critical temperature. This effective temperature is determined from the microscopic properties of the system. The second approach is based on a semiclassical model where classical spins interact with an environment with a quantumlike power spectrum. The parameters that characterize this model can be calculated or extracted from experiments. This semiclassical model quantitatively reproduces the absolute temperature behavior of a magnetic system, thus accounting for the quantum mechanical aspects of its dynamics, even at low temperature. The methods presented here can be readily implemented in current ASD simulations with no additional complexity cost. Published by the American Physical Society 2024

Enhancing sustainability in self-compacting concrete by optimizing blended supplementary cementitious materials

Within concrete engineering, the uptake of self-compacting concrete (SCC) represents a notable trend, delivering improved workability and placement efficiency. However, challenges persist, notably in achieving optimal performance while mitigating environmental impacts, particularly in cement consumption. However, simply reducing the cement content in the mix design can directly compromise the structural-concrete requirements. Towards these challenges, global trends emphasize the utilization of appropriate waste materials in blended concrete. This study explored a promising strategy by integrating supplementary cementitious materials (SCMs) to contribute to the United Nations' Sustainable Development Goals (SDGs) in addition to the engineering contributions. It suggests an optimal combination of Metakaolin (MK) and Limestone Powder (LP) to partially substitute cement. The research methodology employs the response surface method (RSM) to systematically explore the ideal ingredient ratios. Through a comprehensive analysis of orthogonal array of 16 mixes, encompassing both mixture and process variables, this study aims to explain the effects of MK and LP addition on the rheological and mechanical properties of SCC with varying cement replacement levels. In terms of mixture constituents, the total composition of cement, MK, and LP was fixed at 100%, while coarse aggregate (CA), fine aggregate (FA), and the water-to-binder ratio were held as process variables. In order to assess the rheological properties of the mix-design, various tests including slump flow, L-box, and sieve segregation were conducted. Additionally, to evaluate mechanical strength, samples were tested for compressive strength at both 7 and 28 days. Findings from the experiments reveal higher concentrations of MK result in reduced workability and hardened properties. Through RSM-based designed experimentation covering both rheological and mechanical aspects, it is observed that the optimal cement replacement level lies between 40 and 55%. The findings of this study contribute to the advancement of sustainable and structurally robust concrete practices, offering insights into the optimal utilization of SCMs to meet both engineering requirements and environmental sustainability goals.

MechanoBase: a comprehensive database for the mechanics of tissues and cells.

Mechanical aspects of tissues and cells critically influence a myriad of biological processes and can substantially alter the course of diverse diseases. The emergence of diverse methodologies adapted from physical science now permits the precise quantification of the cellular forces and the mechanical properties of tissues and cells. Despite the rising interest in tissue and cellular mechanics across fields like biology, bioengineering and medicine, there remains a noticeable absence of a comprehensive and readily accessible repository of this pertinent information. To fill this gap, we present MechanoBase, a comprehensive tissue and cellular mechanics database, curating 57 480 records from 5634 PubMed articles. The records archived in MechanoBase encompass a range of mechanical properties and forces, such as modulus and tractions, which have been measured utilizing various technical approaches. These measurements span hundreds of biosamples across more than 400 species studied under diverse conditions. Aiming for broad applicability, we design MechanoBase with user-friendly search, browsing and data download features, making it a versatile tool for exploring biomechanical attributes in various biological contexts. Moreover, we add complementary resources, including the principles of popular techniques, the concepts of mechanobiology terms and the cellular and tissue-level expression of related genes, offering scientists unprecedented access to a wealth of knowledge in this field of research. Database URL: https://zhanglab-web.tongji.edu.cn/mechanobase/ and https://compbio-zhanglab.org/mechanobase/.

Feasibility of the BBNJ Agreement to regulate bioprospecting in the Southern Ocean

This paper investigates the potential regulatory frameworks applicable to marine bioprospecting in the Southern Ocean and considers the activity could potentially fall under the purview of both the Antarctic Treaty System and the Biodiversity Beyond National Jurisdiction Agreement. Through a comparative analysis, this paper discerns the overlap of application and divergence in rules between the two regulatory frameworks, particularly concerning the specific provisions for regulating marine bioprospecting. This includes dissecting differences in the rules regulating the procedures for access to marine genetic resources and the associated benefit-sharing mechanisms. By synthesizing the SWOT analysis and strategic analysis, this paper identifies the internal and external factors influencing the application of the BBNJ Agreement to bioprospecting regulation within the Southern Ocean. It concludes that, due to the priority application of ATS and the region`s unique geopolitical context, the BBNJ Agreement may encounter challenges in the direct implementation and governance of marine bioprospecting. The principle of not undermining should be observed to harmonize application with ATS. Meanwhile, the BBNJ Agreement may contribute to a self-revolution of the ATS in regulating marine bioprospecting, particularly in the aspect of mechanisms for equitable benefit-sharing.

#2892 The role of physical activity in onco-nephrology; a new weapon in the management of urological malignancies

Abstract Background and Aims New clinical evidence demonstrated that Physical Activity (PA) brings numerous benefits both at the level of Health-RelatedQuality of Life (HRQoL), biological mechanisms and at the psychological level. Indeed, it is well known that cancer treatments results in a series of symptoms and side effects that debilitates the patients with cancer and can be counteracted with physical activity. PA has an effect on several aspects of biological mechanisms: sex hormones, metabolic hormones, inflammation and adiposity, and immune function. Furthermore, strong evidence shows that aerobic or combined (aerobic and endurance) training reduces symptoms of anxiety, depression and fatigue. Combined training also leads to improvements in HRQoL, preventing and improving muscle loss and sarcopenia. This study aims to assess the influence of physical activity on this improved scenario. Method A consecutive cohort of 82 pts was enrolled in the Urological Department at San Raffaele Scientific Institute between 2018-2021. The control group (CT) was composed of 31 patients affected by CKD alone (GFR < 60 ml/min/1.73 m2, K-DIGO 2012 classification) and 51 patients with CKD and a recent history of urological malignancies (within 12 months) represented the case group (CS). Inclusion criteria were: Age (>18 years old), eGFR (<60 ml/min/1.73), Malnutritional Screening Tool (MST<2), Urological Cancer aggressiveness (no metastatic process), Informed consent (signed). Each patient underwent an initial nephrological and nutritional evaluation during which a conventional CKD Mediterranean-like diet with a controlled protein intake (MCPD) (0.6-1 g total protein/kg body weight/die and 30-35 kcal/kg body weight/die) was prescribed together with physical activity recommendation according to The National Kidney Foundation (NKF) for a period of 6 months (±2 months). Physical activity recommendations included some aerobic exercise for 30 min on most days of the week, plus other activities to increase muscle strength (exercises with resistance bands) e/o to improve flexibility (such as stretching) once or twice a week. To assess the influence of physical activity within the collaborative nephrologist-nutritionist approach (NNCA) on enhanced kidney function, the Rapid Assessment of Physical Activity (RAPA) test was administered to each patient. The test consists of two indicators: RAPA 1 will indicate aerobic physical activity levels (from 0=sedentary to 7=physically active), while RAPA 2 will indicate other types of exercises (0=none; 1=strength; 2=flexibility; 3=both). Subsequently, Bioelectrical Impedance Analysis (BIA) was conducted on all participants in the cohort to collect data on Body Cell Mass per height squared (BCM/h2), Phase Angle (PA), Extracellular Mass (ECM)/BCM, and Extracellular to Intracellular water ratio (ECW/ICW). Statistical analysis: Linear regression and Pearson's Chi-Squared test; Data analysis: R programming language and RStudio integrated development environment. Results Table 1 shows the patient's baseline characteristics. Table 2 shows anthropometric indices and parameters at pre- and post-dietary and nephrological intervention. Table 3 underlines the poor condition prevalent in CKD patients with or without oncological history, also confirmed by the low level of usual physical activity detected by the RAPA test at T0. Sure enough, our population was mainly inactive and sedentary. Results show that, after the intervention, our patients became regularly active (RAPA 1 score T0: 2.47; RAPA 1 score T1: 3.17; Delta = + 0.7, p < 0.0001); the same trend was observed for RAPA 2 score (observed increase 14%, p < 0.002). Conclusion Based on these findings, it can be inferred that standard clinical care should incorporate thorough assessment of both nutritional status and PA. The adoption of a MCPD, coupled with exercise training within a collaborative nephrologist-nutritionist approach, emerges as a potential strategy to enhance the HRQoL of this particular kind of patient.

Methane Formation Induced via Face-to-Face Orientation of Cyclic Fe Porphyrin Dimer in Photocatalytic CO2 Reduction.

Iron porphyrins are known to provide CH4 as an eight-electron reduction product of CO2 in a photochemical reaction. However, there are still some aspects of the reaction mechanism that remain unclear. In this study, we synthesized iron porphyrin dimers and carried out the photochemical CO2 reduction reactions in N,N-dimethylacetamide (DMA) containing a photosensitizer in the presence of 1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole (BIH) as an electron donor. We found that, despite a low catalytic turnover number, CH4 was produced only when these porphyrins were facing each other. The close proximity of the cyclic dimers, distinguishing them from a linear Fe porphyrin dimer and monomers, induced multi-electron CO2 reduction, emphasizing the unique role of their structural arrangement in CH4 formation.

Special Aspects of Mechanisms of Protection of the Constitutional Right to Housing of Parties to Shared Equity Construction

Special Aspects of Mechanisms of Protection of the Constitutional Right to Housing of Parties to Shared Equity Construction

A Low-Cost Soft Gripper for Automated Pick-and-Place Systems

The study introduces a pioneering low-cost soft gripper designed for the automation industry, specifically targeting sensitive handling requirements in the food and health sectors. Utilizing rubber or elastic composites, the gripper combines improved sensitivity and adaptability to handle delicate materials safely and efficiently, aligning with stringent industry standards. Central to the design is a pneumatic control system that ensures precise manipulation, allowing the gripper to adapt to varying object contours without causing damage. This innovation not only addresses the mechanical aspects of soft robotics but also integrates seamlessly with Industry 4.0 technologies through smart sensors and AI algorithms, enhancing operational intelligence and versatility. By leveraging additive manufacturing techniques, the design also achieves significant cost reductions, facilitating broader adoption. This study's soft gripper represents a critical step forward in the development of robotic systems that can perform complex tasks with high sensitivity and economic efficiency, promising transformative impacts on the automation capabilities of sensitive industrial sectors.

Assessment of heavy oil recovery mechanisms using in-situ synthesized CeO2 nanoparticles

This project investigated the impact of low-temperature, in-situ synthesis of cerium oxide (CeO2) nanoparticles on various aspects of oil recovery mechanisms, including changes in oil viscosity, alterations in reservoir rock wettability, and the resulting oil recovery factor. The nanoparticles were synthesized using a microemulsion procedure and subjected to various characterization analyses. Subsequently, these synthesized nanoparticles were prepared and injected into a glass micromodel, both in-situ and ex-situ, to evaluate their effectiveness. The study also examined the movement of the injected fluid within the porous media. The results revealed that the synthesized CeO2 nanoparticles exhibited a remarkable capability at low temperatures to reduce crude oil viscosity by 28% and to lighten the oil. Furthermore, the addition of CeO2 nanoparticles to the base fluid (water) led to a shift in the wettability of the porous medium, resulting in a significant reduction in the oil drop angle from 140° to 20°. Even a minimal presence of CeO2 nanoparticles (0.1 wt%) in water increased the oil production factor from 29 to 42%. This enhancement became even more pronounced at a concentration of 0.5 wt%, where the oil production factor reached 56%. Finally, it was found that the in-situ injection, involving the direct synthesis of CeO2 nanoparticles within the reservoir using precursor salts solution and reservoir energy, led to an 11% enhancement in oil production efficiency compared to the ex-situ injection scenario, where the nanofluid is prepared outside the reservoir and then injected into it.

Synthesis of silsesquioxane-linked polyester with liquid crystalline backbone chain

A novel procedure for the synthesis of a 3D network polyester bearing silsesquioxane cores was executed to prepare the ternary silsesquioxane-linked copolyester BNH (BNH4 and BNH8) based on 4-acetoxy benzoic acid (ABA), 6-acetoxy-2-naphthoxylic acid (ANA), and a silsesquioxane-cored monomer (CSQ-AHA4 or CSQ-AHA8). The thermal data and phase behavior indicated that moderate crosslinking would reduce the stacking of the backbones, thereby enhancing the mobility of the backbone. However, greater crosslinking would limit the movement of the backbone, while the 3D cross-linked structure enhanced the structural stability of the phase region and the uniformity of the crystal size distribution. The loose fiber bundles showed that the participation of the 3D configuration and silsesquioxane increased the chain flexibility, and facilitated the formation of strong polyester ultrafine fibers. It was possible to improve the lateral mechanical properties of the oriented polyester materials, probably improving the mechanical properties aspect ratio of thin film materials.

Numerical Investigation of the Coaxial Geothermal Heat Exchanger Performance

Space heating and cooling using geothermal heat exchangers is a promising environmentally friendly green energy solution. Modeling these energy storage systems is crucial for optimizing their design and operation. In this context, the present study consists of numerically investigating the effects of various physical properties, including thermal conductivity, density, and specific heat capacity of each material, as well as flow velocity, on the process of heat transfer in vertical geothermal heat exchangers using coaxial pipes to optimize their energy performance. Numerical simulations were carried out using Gambit-Fluent software. Different materials that make up the coaxial heat exchanger structure studied were tested to highlight their effects on the progress of heat flux and temperature. Thermal and fluid mechanics aspects were also studied. At the end of this study, a comparative analysis was carried out using the U-tube geothermal heat exchanger. The results indicate that the heat exchanger using a coaxial tube demonstrates superior thermal efficiency compared to the U-tube configuration. It has been found that using a low velocity with an appropriate selection of tube, grout, and soil materials results in enhanced dynamic exchanges, thereby enhancing the thermal efficiency of the geothermal exchanger.