Volumetric Capacity Research Articles

Determination of the Thermal Conductivity and Volumetric Heat Capacity of Substance from Heat Flux

The study of nonlinear problems related to heat transfer in a substance is of great practical important. Earlier, this paper’s authors proposed an effective algorithm for determining the volumetric heat capacity and thermal conductivity of a substance based on experimental observations of the dynamics of the temperature field in the object. In this paper, the problem of simultaneous identification of temperature-dependent volumetric heat capacity and thermal conductivity of the substance under study from the heat flux at the boundary of the domain is investigated. The consideration is based on the first boundary value problem for a one-dimensional unsteady heat equation. The coefficient inverse problem under consideration is reduced to a variational problem, which is solved by gradient methods based on the application of fast automatic differentiation. The uniqueness of the solution of the inverse problem is investigated.

Demonstration of a Validated Direct Current Wearable Device for Monitoring Sweat Rate in Sports

Sweat rate magnitude is a desired outcome for any wearable sensing patch dedicated to sweat analysis. Indeed, sweat rate values can be used two-fold: self-diagnosis of dehydration and correction/normalization of other physiological metrics, such as Borg scale, VO2, and different chemical species concentrations. Herein, a reliable sweat rate belt device for sweat rate monitoring was developed. The device measures sweat rates in the range from 1.0 to 5.0 µL min−1 (2 to 10 µL min−1 cm−2), which covers typical values for humans. The working mechanism is based on a new direct current (DC) step protocol activating a series of differential resistance measurements (spatially separated by 800 µm) that is gradually initiated by the action of sweat, which flows along a customized microfluidic track (~600 µm in width, 10 mm in length, and 235 µm in thickness). The device has a volumetric capacity of ~16 µL and an acquisition frequency between 0.010 and 0.043 Hz within the measured sweat rate range. Importantly, instead of using a typical and rather complex AC signal interrogation and acquisition, we put forward the DC approach, offering several benefits, such as simplified circuit design for easier fabrication and lower costs, as well as reduced power consumption and suitability for wearable applications. For the validation, either the commercial sweat collector (colorimetric) or the developed device was performed. In five on-body tests, an acceptable variation of ca. 10% was obtained. Overall, this study demonstrates the potential of the DC-based device for the monitoring of sweat rate and also its potential for implementation in any wearable sweat platform.

Aproximación al conocimiento de las estructuras de almacenaje en el asentamiento semiurbano de la Antigua Ciudad de Quilmes (Tucumán-Argentina)

The role of storage strategies throughout history is unquestionable. The old city of Quilmes offers features that indicate a possible emphasis placed on the construction of structures oriented to that end. The objectives of this research are: (1) to carry out the first systematic survey of the semi-urban system of the Old City of Quilmes; (2) differentiate between structures of diverse function through morphological clues; (3) identify and record structures traditionally associated with storage; and (4) estimate the area occupied by the aforementioned structures and their volumetric capacity. For this, a non-invasive geoarchaeological approach is proposed through the use of remote sensors and digital models, accompanied by statistical analysis. The set of information has made it possible to establish that the structures similar to storage use would cover a total area estimated at 26,146 m2 with an estimated volume of 43,761 m3 and probably contributed to improving food security during the period of indigenous resistance (1535-1667). This constitutes the first systematic approach to this subject.

Ultrahigh-surface area covalent organic frameworks for methane adsorption.

Developing porous materials with ultrahigh surface areas for gas storage (for example, methane) is attractive but challenging. Here, we report two isostructural three-dimensional covalent organic frameworks (COFs) with a rare self-catenated alb-3,6-Ccc2 topology and a pore size of 1.1 nanometer. Notably, these imine-linked microporous COFs show both high gravimetric Brunauer-Emmett-Teller (BET) surface areas (~4400 square meters per gram) and volumetric BET surface areas (~1900 square meters per cubic centimeter). Moreover, their volumetric methane uptake reaches up to 264 cubic centimeter (standard temperature and pressure) per cubic centimeter [cm3 (STP) cm-3] at 100 bar and 298 kelvin, and they exhibit the highest volumetric working capacity of 237 cm3 (STP) cm-3 at 5 to 100 bar and 298 kelvin among all reported porous crystalline materials.

Bubbling Chemical Vapors in Molten Metal toward XIV-Group Nanosheets.

Two-dimensional (2D) XIV-group nanosheets (germanene, silicene, and stannene) possess unique physical and chemical features promising in fields of electronics, energy storage, and conversions. However, preparing these nanosheets is challenging owing to their non van der Waals structure with strong chemical bonds inside. Herein, a bubbling chemical-vapor growth method is proposed to synthesize these XIV-group nanosheets by bubbling XIV-group-element chlorides in molten sodium. During the synthetic process, XIV-group materials are formed by the reaction of XIV-group element chlorides with strong reducing sodium, then nucleated, and finally isolated to 2D nanosheets in the gas-liquid interface. With the collapse of vapor bubbles and subsequent injection, 2D nanosheets are continuously produced. The nanosheets (Ge) possess a thickness of ∼3.8 nm and a lateral size of ∼2.0 μm. Combining with graphene, the hybrid and flexible films are obtained, delivering a volumetric specific capacity of 4785 mAh cm-3 and superior cycling stability (over 4000 cycles) in lithium-ion batteries.

Self-supporting Mg-Sn alloy anode for high-energy Li-ion batteries

Due to advantages such as low reaction potential, high gravimetric and volumetric capacity, and minimal structural changes during interaction with lithium, the research on Mg anodes in Li-ion batteries has garnered significant attention. However, the slow diffusion kinetics of Li in Mg limits its further advancement. In this study, we designed an ultrathin, flexible, and self-supporting Mg–Sn alloy anode featuring an interleaved two-phase distribution. The electrode was fabricated through a simple one-step magnetron sputtering method, which circumvents the need for complex procedures like slurry preparation and coating. Both theoretical calculations and experimental results indicate that the introduction of a second phase(Mg2Sn phase) significantly enhances the interaction between Mg and Li, thereby unlocking the lithium storage capabilities of Mg. The developed Mg–Sn alloy electrode demonstrates a charge specific capacity of 1,618 mAh g−1 at 50 mA g−2 and maintains a capacity of 421 mAh g−1 after 50 cycles.

Characteristics of constant pressure dehydrogenation and construction of linear diffusion model for solid hydrogen storage materials: A case study of TiMn1.5 alloy

Solid-state hydrogen storage is considered to be the most promising hydrogen storage technology because of its high volumetric capacity and good security. The process of hydrogenation and dehydrogenation of solid hydrogen storage materials can be characterized by a diffusion kinetic model, which can be used to guide the safe and efficient application of hydrogen storage materials. Currently, experimental study on the dehydrogenation characteristics under constant pressure outer boundary condition has not been carried out methodically, and a simple and reliable diffusion kinetic model under this condition should be established based on the experimental results. In this study, an experimental platform for hydrogen absorption and constant pressure dehydrogenation of solid hydrogen storage materials was independently established. The TiMn1.5 alloy and its interstitial hydrides were taken as the experimental research objects to conduct constant pressure dehydrogenation tests, and the dehydrogenation properties at different temperatures were systematically studied. The results show that the dehydrogenation rate decreases with the increase of testing time. The ultimate capacity of hydrogen release increases first and then decreases with the increasing temperature, reaching the maximum value at 30 °C. It is found that the diffusion coefficient increases linearly with time during constant pressure dehydrogenation process. On this basis, a linear diffusion kinetic model is established. The initial diffusion coefficient D0 calculated by the new model has a quadratic polynomial relationship with temperature, and the increase coefficient α of diffusion coefficient has a linear relationship with temperature. According to the mathematical expressions, the dehydrogenation process of TiMn1.5 alloy at different temperatures can be predicted. The research results can provide theoretical guidance for the safe, efficient and controllable application of hydrogen storage materials.

Computational Exploration of Adsorption-Based Hydrogen Storage in Mg-Alkoxide Functionalized Covalent-Organic Frameworks (COFs): Force-Field and Machine Learning Models.

Hydrogen is a clean-burning fuel that can be converted to other forms. of energy without generating any greenhouse gases. Currently, hydrogen is stored either by compression to high pressure (>700 bar) or cryogenic cooling to liquid form (<23 K). Therefore, it is essential to develop safe, reliable, and energy-efficient storage technology that can store hydrogen at lower pressures and temperatures. In this work, we systematically designed 2902 Mg-alkoxide-functionalized covalent-organic frameworks (COFs) and performed high-throughput (HT) computational screening for hydrogen storage applications at 111, 231, and 296 K. To accurately model the interaction between Mg-alkoxide sites and molecular hydrogen, we performed MP2 calculations to compute the hydrogen binding energy for different types of functionalized models, and the data were subsequently used to fit modified-Morse force field (FF) parameters. Using the developed FF models, we conducted HT grand canonical Monte Carlo (GCMC) simulations to compute hydrogen uptakes for both original and functionalized COFs. The generated data were subsequently used to evaluate the materials' gravimetric and volumetric storage performance at various temperatures (111, 231, and 296 K). Finally, we developed machine learning (ML) models to predict the hydrogen storage performance of functionalized structures based on the features of the original structures. The developed model showed excellent performance with a mean absolute error (MAE) of 0.061 wt % and 0.456 g/L for predicting the gravimetric and volumetric deliverable capacities, enabling a quick evaluation of structures in a hypothetical COF database. The screening results demonstrated that the Mg-alkoxide functionalization yields greater improvements in volumetric H2 storage capacities for COFs with smaller pores compared to those with larger (mesoporous) pores.

Coupling Manipulation of Interfacial Chemistry and Coordination Structure in Vanadium Oxides Enables Rapid Magnesium Ion Diffusion Kinetics

AbstractRechargeable magnesium batteries (RMBs) are a highly promising energy storage system due to their high volumetric capacity and intrinsic safety. However, the practical development of RMBs is hindered by the sluggish Mg2+ diffusion kinetics, including at the cathode‐electrolyte interface (CEI) and within the cathode bulk. Herein, we propose an efficient strategy to manipulate the interfacial chemistry and coordination structure in oligolayered V2O5 (L−V2O5) for achieving rapid Mg2+ diffusion kinetics. In terms of the interfacial chemistry, the specific exposed crystal planes in L−V2O5 possess strong electron donating ability, which helps to promote the degradation dynamics of C−F/C−S bonds in the electrolyte, thereby establishing the inorganic‐organic interlocking CEI layer for rapid Mg2+ diffusion. In terms of the coordination structure, the straightened V−O structure in L−V2O5 provides efficient ions diffusion path for accelerating Mg2+ diffusion in the cathode. As a result, the L−V2O5 delivers a high reversible capacity (355.3 mA h g−1 at 0.1 A g−1) and an excellent rate capability (161 mAh g−1 at 1 A g−1). Impressively, the interdigital micro‐RMBs is firstly assembled, exhibiting excellent flexibility and practicability. This work gives deeper insights into the interface and interior ions diffusion for developing high‐kinetics RMBs.

A Bandgap‐Tuned Tetragonal Perovskite as Zero‐Strain Anode for Potassium‐Ion Batteries

AbstractPIBs are emerging as a promising energy storage system due to high abundance of potassium resources and theoretical energy density, however, progress of PIBs is severely hindered by structural instability and poor cycling of anode material during continual insertion and extraction of larger‐sized K+. Hence, developing anode material with structural stability and stable cycling remains a great challenge. Herein, band gap‐tuned Mo‐doped and carbon‐coated lead titanate (CMPTO) with zero‐strain K+ storage is presented as ultra‐stable PIBs anode. Mo doping introduces narrowed band gap and optimized crystal lattice for enhanced intrinsic electron and ion transfer. Demonstrated by in situ XRD characterizations, the crystal structure stays stable with unchanged peak positions, fully revealing zero‐strain characteristic of CMPTO anode during potassium storage for stable cyclic capability. Ultimately, CMPTO anode achieved ultra‐stable cycling performance of 7000 cycles at 500 mA g−1 with high capacity retention of 90 % and considerable specific capacity of 130.9 mAh g−1 after 600 cycles at 100 mA g−1; with relatively large density, CMPTO realized eminent volumetric capacity of 1111.09 mAh cm−3 and ultra‐long cycling life of 10000 cycles at 7041 mA cm−3. This work introduces a promisingly new route into developing anode materials with ultra‐stable performance for PIBs.

In Situ Molecular Reconfiguration of Pyrene Redox-Active Molecules for High-Performance Aqueous Organic Flow Batteries.

Aqueous organic flow batteries (AOFBs) hold great potential for large-scale energy storage, however, scalable, green, and economical synthetic methods for stable organic redox-active molecules (ORAMs) are still required for their practical applications. Herein, pyrene-based ORAMs are obtained via an in situ organic electrolysis strategy in a flow cell. It is revealed that the water attacking pyrenes restructured molecules to produce a variety of isomers and dimers during the electrolysis, which can be modulated by regulating the local electron cloud density and steric hindrance of pyrene precursors. As a result, the molecularly reconfigured pyrene-based catholytes, even without any further purification, achieved a high electrolyte utilization of ≈96% and volumetric capacity above 50AhL-1. Inspiringly, remarkable cell stability with almost no capacity decay for ≈70 days is achieved, benefiting from the robust aromatic structure of the pyrene cores. The insights into the in situ electrosynthesis of pyrene-based ORAMs provided in the work will provide guidance for designing ultra-stable ORAMs for AOFB applications.

Influence of the position of an Internal Heat Exchanger on the performance of a Dual-Evaporator Ejector Refrigeration System

Abstract Energy and exergy analyses were performed to assess the effect of IHX position on the performance characteristics of a dual-evaporator refrigeration system using an ejector as expansion device. Three positions were tested. The first one generates a superheating at the suction of the compressor, the second generates a superheating of the secondary fluid at the inlet of the ejector and the third generates a superheating of the primary fluid at the inlet of the motive nozzle. The results of the simulation show that it is the second position which leads to the best increases in performance characteristics of the refrigeration system. With improvements in COP, Volumetric Cooling Capacity, exergy efficiency and refrigeration cooling capacity of 9.38%, 9.58%, 5.18% and 19.12%, respectively R1234yf is the best fluid. However, the use of IHX is not recommended for R717, especially in position 1. The results also show that the contribution of IHX to increasing system performance is greater the higher the degree of sub-cooling and the lower the IHX effectiveness. It was also noted that system performance increases with condensing and refrigeration temperatures and decreases with freezing temperature.

Catalyst Design and Engineering for CO2-to-Formic Acid Electrosynthesis for a Low-Carbon Economy.

Formic acid (FA) has emerged as a promising candidate for hydrogen energy storage due to its favorable properties such as low toxicity, low flammability, and high volumetric hydrogen storage capacity under ambient conditions. Recent analyses have suggested that FA produced by electrochemical carbon dioxide (CO2) reduction reaction (eCO2RR) using low-carbon electricity exhibits lower fugitive hydrogen (H2) emissions and global warming potential (GWP) during the H2 carrier production, storage and transportation processes compared to those of other alternatives like methanol, methylcyclohexane, and ammonia. eCO2RR to FA can enable industrially relevant current densities without the need for high pressures, high temperatures, or auxiliary hydrogen sources. However, the widespread implementation of eCO2RR to FA is hindered by the requirement for highly stable and selective catalysts. Herein, the aim is to explore and evaluate the potential of catalyst engineering in designing stable and selective nanostructured catalysts that can facilitate economically viable production of FA.

Predicting the volumetric heat capacity of freezing soils using the soil freezing characteristic curve

The heat capacity during the freezing process is a vital hydrothermal parameter. It is difficult to experimentally measure the heat capacity of freezing soils. Therefore, in this study, we proposed a new method to estimate the volumetric heat capacity based on the combination of the weighted arithmetic mean model for volumetric heat capacity and soil freezing characteristic curve (SFCC) estimation model. Five specific heat capacity models for solid particle and six SFCC estimation models were introduced. It can be concluded that the six SFCC-based volumetric heat capacity models with specific heat capacity of solid particle = 0.725 MJMg-1K−1 exhibited the best performance. Among the six SFCC-based volumetric heat capacity models, the Kong et al-based volumetric heat capacity model has the best performance in predicting the volumetric heat capacity. The predicted SFCC-based volumetric heat capacity model is easy to use and can be applied to mimic the variation of volumetric heat capacity with subzero temperature.

Fluoride Ion Storage and Conduction Mechanism in Fluoride Ion Battery Positive Electrode, Ruddlesden-Popper-Type Layered Perovskite La1.2Sr1.8Mn2O7 Crystal.

Structural characteristics on fluoride ion storage and conduction mechanism in La1.2Sr1.8Mn2O7, and its fluoridated materials, La1.2Sr1.8Mn2O7F and La1.2Sr1.8Mn2O7F2, for an all-solid-state fluoride ion battery positive electrode with a high volumetric capacity surpassing those of lithium-ion ones have been revealed using the Rietveld method and maximum entropy method. In La1.2Sr1.8Mn2O7, once the F- ions are taken into the NaCl slabs in its crystal through the charging process, it forms two stable fluoride compounds, La1.2Sr1.8Mn2O7F and La1.2Sr1.8Mn2O7F2, with the help of the Mn oxidation reaction. In these oxyfluorides, thermal vibrations of the F- ions inserted are much larger, especially in the a-b plane, than along the c axis. When surplus energy, such as an electric field for charging, is applied to these crystals at near room temperature or higher, the anions immediately begin to jump to their neighboring lattice sites, resulting in sufficiently rapid and large ionic conduction. The MEM analyses and density functional theory (DFT) calculations have revealed that the F- ions enable to easily travel along the ⟨110⟩ directions in the NaCl slabs of these crystals. These structural features thus make La1.2Sr1.8Mn2O7 and its fluorides possess both of two features incompatible with each other, ion storage and conduction, indispensable for rechargeable batteries.

Machine Learning Predictions of Methane Storage in MOFs: Diverse Materials, Multiple Operating Conditions, and Reverse Models.

A machine learning (ML) model is developed for predicting useable methane (CH4) capacities in metal-organic frameworks (MOFs). The model applies to a wide variety of MOFs, including those with and without open metal sites, and predicts capacities for multiple pressure swing conditions. Despite its wider applicability, the model requires only 5 measurable structural features as input, yet achieves accuracies that surpass less-general models. Application of the model to a database of more than a million hypothetical MOFs identified several hundred whose capacities surpass that of the benchmark MOF, UMCM-152. Guided by the computational predictions, one of the promising candidates, UMCM-153, was synthesized and demonstrated to achieve superior volumetric capacity for CH4. Feature importance analyses reveal that pore volume and gravimetric surface area are the most important features for predicting CH4 capacity in MOFs. Finally, a reverse ML model is demonstrated. This model predicts the set of elementary MOF structural properties needed to achieve a desired CH4 capacity for a prescribed operating condition.

Physical and electrochemical performances of novel tellurium composite films as anode applications in energy storage systems

Portable electronic devices and electric cars use lithium-ion batteries, but clumping lithium alloys limit their lifespan. Due to their strong electronic conductivity, volumetric capacity, and high energy density, researchers are conducting research on electrochemical metal cells utilizing tellurium for high-performance batteries. Theoretically, lithium-tellurium batteries can improve energy densities three times more than lithium-ion batteries. However, metal-tellurium faces challenges such as low rate capability, unclear redox reactions, intermediate dissolution, and electrode volume changes. This study explores the enhancement of the energy storage capacity of next-generation batteries by fabricating coated electrode films as novel anodes from tellurium, silicon, and graphene. Physical, thermal, and morphological analysis of composite material are investigated by XRD, TEM, TGA, DSC, SEM, UV, and XPS analyses, revealing its rigidity as well as durability through its crystal structure alignment and thermal stability. In electrochemical analysis (CV) at various scan rates, samples that exhibit consistent and high specific capacity (Cp) values at different scan speeds (25, 50, and 100 mV/s) indicate excellent ability to store and maintain charge. Decreasing Cp values with increasing scan rates indicate that the speed of cycling limits the charge transfer kinetics and electrode performance. In EIS, the charge transfer resistances (Rct) for the pure Te, Te + Gr, Te + Si + Gr, and Te + Si samples are 759.07 Ω, 4.21 Ω, 36.39 Ω, and 164.90 Ω, respectively. The Te + Gr sample has the lowest Rct, indicating the best charge transfer efficiency at the electrode contact, whereas the Te + Si + Gr sample has a comparatively lower Rct, indicating better charge transfer kinetics. The combined result exhibits the synergistic impact of tellurium, silicon, and graphene in enhancing the energy storage capacity of future batteries across the industry.

In situ soil moisture and thermal properties estimated using a dual-probe heat-pulse

In situ monitoring of the temporal and spatial distribution of soil moisture and thermal properties are important for studying the water and energy transport in the vadose zone. The single-probe heat-pulse method based on fiber Bragg grating technology (SPHP-FBG) has become a research focus in field monitoring because of its capability to realize quasi-distributed and real-time monitoring. However, the SPHP-FBG method can only obtain thermal conductivity. This study developed a dual-probe heat-pulse method based on FBG (DPHP-FBG). The DPHP-FBG method can measure thermal conductivity (λ), volumetric heat capacity (Cv), and thermal diffusivity (k). Consequently, volumetric soil water content (θ) can be estimated from its linear relationship with Cv. The accuracy of the DPHP-FBG method in the estimation of Cv, λ, and θ was tested under different heating duration and various soil moisture conditions. In addition, Monte Carlo simulation was performed to investigate the impact of FBG measurement errors on accuracy. Finally, a field test was conducted to verify the effectiveness of the developed DPHP-FBG system. The results show that the DPHP-FBG method allows accurate soil moisture and thermal properties estimation without soil-specific calibration. The mean errors of the Cv and θ decrease with the extended heating duration. When the heating lasts 20 s, the measured Cv and θ have mean errors of 0.02 MJ m−3 K−1 and 0.01 m3/m3, respectively, for various moisture conditions. In the field test, the spatio-temporal distribution of soil moisture and thermal properties can be obtained in real time. Thereby, the proposed DPHP-FBG monitoring system is potential to conduct in situ coupled heat and soil moisture measurements at a large scale.

Selection of Solar-Based Water-Splitting Hydrogen Production and Hydrogen Storage Technologies Using Neutrosophic Analytic Hierarchy Process and Neutrosophic Complex Proportional Assessment

Abstract The production of hydrogen through water-splitting using solar energy has the potential to meet the world’s future energy demand while also addressing the issue of greenhouse gas emissions. To compare and select the best technology among solar thermochemical cycles, photoelectrochemical, and photocatalytic water-splitting in terms of solar-to-hydrogen efficiency, production cost, safety, life expectancy, maintenance cost, and detrimental impact on the environment, this study used a multi-criteria decision analysis hybrid called Neutrosophic Analytic Hierarchy Process (NAHP) and Neutrosophic Complex Proportional Assessment (NCOPRAS). The same method was used to determine the best technology for automobiles among compressed hydrogen storage, metal hydrides, metal-organic frameworks, and chemical storage in terms of gravimetric system capacity, volumetric system capacity, safety, system cost, cycle life, energy efficiency, detrimental impact on the environment, and refueling time. There were 4 experts each in hydrogen storage and hydrogen, specifically from the Philippines, Australia, India, Romania, and Italy. All experts’ judgments have a consistency ratio (CR) &lt; 0.1. The priority criterion for hydrogen production was life expectancy (weighted value (WV) = 0.189), and gravimetric system capacity for hydrogen storage (WV = 0.137). The result showed that among all alternatives for hydrogen production, the solar thermochemical cycle was the best (relative significance value (RSV) = 0.3432) as for hydrogen storage, the best technology among the alternatives was metal hydrides (RSV = 0.2575). A sensitivity analysis was used to check the variability and robustness of the solution.

Thermal Performance Of Termite Mold Bricks Reinforced With Empty Fruit Bunch Spikelet And Coconut Fibers

The use of natural fibers to enhance the thermal properties of earth bricks has become increasingly popular. This study investigates the thermal performance of termite mold soil (TMS) reinforced with two types of fibers: coconut fibers (CF) and empty fruit bunch spikelet fibers (EFBSF). Various fiber compositions (0%, 0.5%, 1%, 1.5%, 2%, and 2.5%) were combined with sodium hydroxide (NaOH) treatments at concentrations of 1%, 2%, 3%, and 4%. Laboratory results reveal that TMS exhibits promising physical properties, including a moisture content of 23.64%, a maximum dry density of 1.63 g/cm³, and a plasticity index of 20%, indicating its structural stability and suitability for earth block production. The study also analyzes the chemical properties of EFBSF and CF fibers, noting that CF has a higher holocellulose content (88.0%) compared to EFBSF (33.5%), which impacts moisture retention and structural integrity. Thermal analysis demonstrates that incorporating these natural fibers significantly enhances the thermal performance of TMS. With a 2.5% fiber content, CF reduces thermal effusivity from 1771.43 J/m²Ks^1/2 to 1079.39 J/m²Ks^1/2 and thermal conductivity from 0.86 W/mK to 0.38 W/mK, making it particularly effective in improving insulation in hot conditions. EFBSF also lowers thermal effusivity and conductivity, but to a lesser extent than CF. Additionally, the presence of these fibers reduces volumetric calorific capacity, with CF showing a more pronounced effect. Overall, TMS reinforced with coconut fibers, especially at 1% NaOH and 2.5% fiber content, offers the best thermal performance, suggesting its potential for sustainable construction. This research promotes the use of locally sourced, natural fibers in earth block manufacturing, contributing to the development of more energy-efficient and environmentally friendly building materials.