Initial Resistance Research Articles

Influencing mechanism on sensitivity of carbonized fabric strain sensors and modification of bridge-connection model: Comparison of three silk woven structures

Given the great potential of carbonized fabric strain sensors in wearable devices, carbonized silk fabrics (CSF) with three characteristic woven structures including georgette (CSF-g), crepe de chine (CSF-c) and crepe satin plain (CSF-p) were employed to investigate the dependence of gauge factor (GF) on two critical parameters: initial resistance (R0) and resistance change (ΔR). The results showed that increasing carbonization temperature can effectively reduce R0 and increase GF of CSF-g, but has little effect on CSF-c and CSF-p. It was further found that the GF of both CSF-c and CSF-p were dominated by ΔR related to the crack propagation path, i.e. high sensitivity CSF was typically accompanied by dense “islands” and fine gaps, while low sensitivity CSF was accompanied by wide cracks and sparse “islands”. Accordingly, a modified bridge connection model was proposed to elucidate the relationship between crack morphology and resistance variation. This model successfully achieved continuous exponential fitting of resistance with admirable fitting goodness. Finally, the prepared sensor exhibited an ultra-high GF (916.5) and was well applied in health monitoring and thermal treatment. These efforts put forward guidance to the design and fabrication of ultrasensitive CSF strain sensors.

Hydration properties of magnesium phosphate cement paste mixed with metakaolin and silica fume

AbstractMagnesium phosphate cement (MPC) exhibits a faster setting time and higher early strength, making it suitable for crack repair. However, its application in civil engineering is hindered by its fast initial hydration rate and poor water resistance. To address these limitations, metakaolin (MK) and silica fume (SF) were utilized to enhance the properties of MPC. The effects of MK and SF on the setting time, compressive strength, water resistance, hydration process, and microstructure of MPC were investigated. The results demonstrate that both MK and SF significantly prolong the setting time of MPC and improve its water resistance. The main hydration products of MPC, after incorporating MK and SF, are k‐struvite (MgKPO4·6H2O) and unreacted MgO. The presence of MgSiO3 and AlPO4 also contributes to the enhancement of compressive strength and water resistance. The incorporation of MK and SF actively participates in the hydration reaction of the MPC system. Furthermore, MgSiO3 and AlPO4 intertwine with MKP, resulting in a denser internal structure of the cured MPC, thereby improving its water resistance.

Additive fabrication of pressure sensitive material for flexible pressure sensor and its characteristics

The increasing interest in wearable devices and healthcare has sparked significant advancements in the development of flexible sensors for various applications. In this study, we present the fabrication and characterization of a flexible pressure sensor utilizing a three-dimensional structure of pressure sensitive material, fabricated through a layer-by-layer process. The aim of this research is to investigate the electrical response characteristics of the sensor based on the number of layers in the pressure sensitive material, both under static and dynamic pressure conditions. The pressure sensitive material, consisting of multi-walled carbon nanotubes (MWCNTs) dispersed in polydimethylsiloxane (PDMS), exhibits positive piezo-resistive properties. The flexible pressure sensor was fabricated using direct ink writing (DIW) technology, which enables precise control over the arrangement of the material. We explored the influence of layer configurations on the sensor's initial resistance and electrical resistance changes by varying the number of layers. Our experiments demonstrated a clear trend, indicating that as the number of layers increased, both the initial resistance and electrical resistance change decreased. This behavior can be attributed to the enhanced connectivity among carbon nanotubes within the material, resulting in reduced overall resistance. In addition to static pressure testing, we conducted dynamic pressure experiments to assess the sensor's response under rapidly changing pressure conditions. Our findings suggest that by manipulating the number of layers in the pressure-sensitive material, the sensor's sensitivity and detection range can be tailored to suit specific applications. This approach offers a flexible and unified method for fabricating sensors with diverse response behaviors within a single manufacturing process.

Effect of coating drying conditions on bronze corrosion protection

Waterborne coatings present a green alternative to solvent-borne coatings as only a small amount of organic solvent is released into the environment during drying. However, for waterborne coatings, the drying process is much more challenging due to the slow evaporation of water. In this work, the influence of drying temperature on the protective properties of a waterborne acrylic coating was studied. Its performance in corrosion protection of bronze substrates, representing the bronzes used for the sculptures placed outdoors, was examined. Corrosion properties were evaluated by linear polarization measurements and electrochemical impedance spectroscopy during three-week exposure to artificial acid rain solution. It was found that drying at ambient temperature resulted in modest corrosion protection, while drying at 55 °C ensured greater initial corrosion resistance, which gradually degraded during exposure to acid rain solution accompanied by the coating blistering. Drying of one-layer coating at 40 °C resulted in the formation of clearly visible corrosion products. If the coating was applied in three layers, the drying process was more efficient, leading to slightly higher polarization resistance values without visible corrosion at the bronze surface. Furthermore, the studied waterborne acrylic coating provided good corrosion protection of patinated bronze surfaces. Additionally, it was found that for efficient corrosion protection, it is preferable that the coating contains a corrosion inhibitor in order to avoid substrate corrosion during coating drying. When applied properly, studied coating does not alter the state of surfaces, both bare and patinated, which is important for its application in bronze cultural heritage protection.

Issue-based learning in medical training: report of experience of monitor of the INTA University Center, UNINTA

This article explores the implementation of the issue-based learning methodology in the Physiology discipline of the INTA University Center (UNINTA), emphasizing the enriching experience of students and monitors. Medical physiology, crucial for understanding the basis of pathophysiology, connects basic sciences to medical practice. Monitoria, as a pedagogical tool, seeks to introduce students to the teaching profession and to stimulate the exchange of knowledge. In the methodology, monitors deepened in themes, elaborating objective and open questions to stimulate critical reasoning, focusing on physiological contextualization in clinical practice. Questions were validated by the advisor. Results highlight a gradual increase in adherence to the method, overcoming initial resistance. Teacher collaboration and forms via Google Forms with automatic feedback were essential. The conclusion is that issue-based learning promoted in-depth learning and positive academic outcomes. The monitoring proved valuable, broadening the students-monitors' perspective on the studied content, contributing to comprehensive learning.

Interação de plântulas de soja com rizobactérias benéficas

Beneficial rhizobacteria are multifunctional microorganisms that stimulate plant growth through direct mechanisms such as the solubilization of phosphorus and potassium present in soil minerals, biological nitrogen fixation and production of plant hormones. The objective of this study was to determine the effect of beneficial rhizobacteria on the initial development, promoting growth and resistance of soybean seedlings, aiming not only for increased production but also for agricultural sustainability through the maximization of biological efficiency in the early development of soybean seedlings. The experiment, under controlled conditions, was conducted in a completely randomized design, with four treatments and ten replications. The treatments consisted in the microbiolization of soybean seeds with: 1. Control (without microorganism); 2. Serratia marcenses (BRM 32114); 3. Bacillus spp. (BRM63573) and 4. BRM 32114 + (BRM63573). After the microbiolization of the seeds, they were sown and placed to germinate, after 12 days, the seedlings were harvested and divided into shoots and roots. The roots were washed and photographed with digital camera. The images were analyzed and determined length, diameter, surface area and volume of roots. Then, root and shoot were dried and weighed for biomass determination. Co-inculation, BRM 32114+ BRM63573, promoted greater robustness of the root system of soybean seedlings with increased length (16.2%), diameter (22.5%), volume (43.4%) and dry biomass (29.7%). The dry matter of shoots and total soybean seedlings was superior to the control treatment in all treatments with rhizobacteria. Therefore, plant growth promoting

Psychological Approach Physical Distancing Model on Immune Resistance Imun New Normal Post Pandemic COVID 19

BACKGROUND: The first COVID-19 reported in Indonesia on March 2, 2020, was two cases. Data on March 31, 2020, showed that there were 1528 confirmed cases and 136 deaths. The COVID-19 mortality rate in Indonesia is 8.9%, this figure is the highest in Southeast Asia. As of March 30, 2020, there were 693,224 cases and 33,106 deaths worldwide. Inadequate immune response leads to viral replication and tissue damage. On the other hand, an exaggerated immune response can cause tissue damage. Several other risk factors established by the Centers for Disease Control and Prevention are close contact, including living in the same house as a COVID-19 patient and a history of travel to an infected area. Based on a preliminary study at the Yogyakarta Special Region Health Center and the Borobudur Magelang Health Center, Central Java, there were 95 cases of corona virus and 75% with comorbidities. Of the corona cases in the Special Region of Yogyakarta and in Borobudur, Magelang, Central Java, the body’s resistance decreased. Researchers are interested in taking the title “The Effect of Psychological Approach Physical Distancing on New Normal Immune Resistance after the COVID 19 Pandemic” AIM: It is known the influence of Psychological Approach Physical Distancing on New Normal Immune Resistance after the COVID 19 Pandemic. METHODS: This type of research is Research and Development using a quasi-experimental, “Pre-test Post-test with Control Group Design” design. In this design, there was a comparison group (control), the observations were carried out twice. The first observation was to determine the New Normal maximum resilience after the COVID 19 pandemic before being given Psychological Approach Physical Distancing and the second observation after being given Psychological Approach Physical Distancing with the criteria for comorbid respondents at the Puskesmas. Data were analyzed using pair t-test and Wilcoxon with a significant level of p < 0.05. RESULTS: Differences in initial immune resistance at month 1, month 1 and month 2, and month 2 and month 3 there was a difference with p = 0.000 (< 0.05). CONCLUSION: There is an influence of Psychological Approach Physical Distancing on New Normal Immune Resistance after the COVID 19 Pandemic.

On-Chip Modification of Titanium Electrothermal Characteristics by Joule Heating: Application to Terahertz Microbolometer.

This study demonstrates the conversion of metallic titanium (Ti) to titanium oxide just by conducting electrical current through Ti thin film in vacuum and increasing the temperature by Joule heating. This led to the improvement of electrical and thermal properties of a microbolometer. A microbolometer with an integrated Ti thermistor and heater width of 2.7 µm and a length of 50 µm was fabricated for the current study. Constant-voltage stresses were applied to the thermistor wire to observe the effect of the Joule heating on its properties. Thermistor resistance ~14 times the initial resistance was observed owing to the heating. A negative large temperature coefficient of resistance (TCR) of -0.32%/K was also observed owing to the treatment, leading to an improved responsivity of ~4.5 times from devices with untreated Ti thermistors. However, this does not improve the noise equivalent power (NEP), due to the increased flicker noise. Microstructural analyses with transmission electron microscopy (TEM), transmission electron diffraction (TED) and energy dispersive X-ray (EDX) confirm the formation of a titanium oxide (TiOx) semiconducting phase on the Ti phase (~85% purity) deposited initially, further to the heating. Formation of TiOx during annealing could minimize the narrow width effect, which we reported previously in thin metal wires, leading to enhancement of responsivity.

Abstract B084: Overcoming drug resistance of ‘tri-complex’ pan-RAS inhibitors: Inhibition of mTOR signaling

Abstract Background: RAS mutations occur in ~20% of all cancers that drive tumor progression, and therapy targeting most predominant RAS mutations remains unavailable. Mutant-selective RAS inhibitors (RASi), such as FDA-approved KRAS G12C inhibitors, have demonstrated initial clinical responses but drug resistance frequently emerges that minimize the drug efficacy, mechanistically mediated by RAS signaling reactivation. Methods and Results: To address this challenge, we characterized a class of novel pan-RASi that universally inhibit all RAS mutations, which forms a ‘tri-complex’ with the chaperone protein (cyclophilin A) that specifically binds to RAS, including wild-type RAS (KRAS, NRAS, HRAS). Mutant-selective RASi induced RAS signaling rebound intensively, whereas pan-RASi enabling to inhibit wild-type RAS minimized this rebound, which was surmountable in a concentration-dependent manner. Importantly, pan-RASi abrogated cell viability in patient-derived KRAS-mutant cancer organoids rather than in normal patient-derived wild-type RAS organoids, implicating drug selectivity and manageable toxicity. Interestingly, intrinsic resistance to pan-RASi was rare in RAS-mutant cancer cell screening but was observed only in a handful of pancreatic and lung cancer cell lines. Our time-resolved signaling analyses of pan-RASi treatment showed the re-activation of mTOR signaling and a contrast correlation that mTOR signaling decreased in sensitive lines but remained in resistant lines, underscoring the critical contribution of mTOR pathways to RASi resistance. Mechanistically, we further identified mTOR signaling that drives intrinsic resistance to pan-RASi, and combined pan-RASi with mTOR inhibitors (mTORi) suppressed mTOR signaling in resistant lines, thereby improving efficacy. Conclusion: Pan-RASi hold promise in treating RAS-mutant cancer clinically and a combination of pan-RASi with mTORi can improve drug efficacy. Citation Format: Qingxiang (Nick) Lin. Overcoming drug resistance of ‘tri-complex’ pan-RAS inhibitors: Inhibition of mTOR signaling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B084.

Wide strain range and high sensitivity sandwich structure CNTs/AgNWs/CNTs/TPU strain sensors for human motion detection

Nowadays, designing a flexible strain sensor that offers both high sensitivity and a wide operating range has been a significant challenge. However, this paper demonstrates the successful preparation of a sandwich-structured, flexible strain sensor with high sensitivity and wide operating range through vacuum-assisted filtration. The substrate of sensor is composed of electrospinning TPU. The three conductive layers of the sensor consist of CNTs, AgNWs, and CNTs. The AgNWs provide extremely low initial resistance and serve to bridge the individual CNTs islands under large strains. The CNTs/AgNWs/CNTs/TPU flexible strain sensor boasts a high sensitivity (GF=1005.8), a wide strain range (up to 350%), and fast response time (39 ms). It also maintains a long working range and long-term usage stability at 2500 cycles. Additionally, the electrothermal and photothermal performance of the sensor were investigated, which revealed a rapid temperature rise to 93.1 °C at 5 V and 80.8 °C at 500 mW/cm2 irradiation intensity. This sensor can accurately monitor the full range of human motion, from tiny pulse and breathing to large-scale finger joint flexion. These findings suggest that our sensor could have great potential for application in wearable devices as well as body health monitoring.

Performance Evaluation and Real-world Challenges of IoT-Based Smart Fuel Filling Systems with Embedded Intelligence

Integrating the Internet of Things (IoT) with smart fueling systems has the potential to revolutionize the fuel industry, leading to better resource management and increased operational efficiency. With the increasing integration of machine learning techniques, these systems are capable of self-learning, adaptation, and predictive decision making. However, the effectiveness of these advanced systems in real-life situations remains an area of intense interest and research. in operational efficiency and reduces resource waste by 10% compared to conventional systems. Additionally, system bottlenecks were identified mainly in data trans- mission (delayed by up to 20% in high traffic cases) and hardware malfunctions due to environmental factors. End user feedback indicates a satisfaction level of 85%, with an emphasis on system responsiveness and fuel prediction recommendations. Challenges mainly come from software issues, unwanted environmental interference and ’some initial resistance from users accustomed to conventional systems. However, with data in hand, the benefits of integrating intelligence into IoT-based fueling systems offer a sustainable and efficient future for the fuel industry. Recommendations are made to improve data transmission channels, develop robust hardware for extreme conditions, and conduct targeted user education campaigns.

Current Imbalance in Dissimilar Parallel-Connected Batteries and the Fate of Degradation Convergence

Abstract This paper proposes an analytical framework describing how initial capacity and resistance variability in parallel-connected battery cells may inflict additional variability or reduce variability while the cells age. We derive closed-form equations for current and SOC imbalance dynamics within a charge or discharge cycle. These dynamics are represented by a first-order equivalent circuit model and validated against experimental data. To demonstrate how current and state of charge (SOC) imbalance leads to cell degradation, we developed a successive update scheme in which the intercycle imbalance dynamics update the intracycle degradation dynamics, and vice versa. Using this framework, we demonstrate that current imbalance can cause convergent degradation trajectories, consistent with previous reports. However, we also demonstrate that different degradation assumptions, such as those associated with SOC imbalance, may cause divergent degradation. We finally highlight the role of different cell chemistries, including different OCV function nonlinearities, on system behavior, and derive analytical bounds on the SOC imbalance using Lyapunov analysis.

Synergistic Municipal-community partnership: Resolving Challenges in the Implementation of the National Slum Upgrading Program (KOTAKU) in Gajah Wong Riverbank Area, Yogyakarta

The successful resolution of challenges faced during the implementation of the National Slum Upgrading (KOTAKU) Program in Gajah Wong Riverbank area, marked by initial resistance from affected communities, was achieved through the inclusive engagement of diverse community elements and collaborating agencies. This intricate interplay among stakeholders has a profound influence on the program’s effectiveness. This study aims to unravel the dynamic relationships forged among various agencies and community components within the conflict management framework, ultimately enhancing program implementation. To attain this objective, a qualitative methodology employing a case study approach was utilized. The investigation revealed that the local government, in executing the National Slum Upgrading (KOTAKU), fostered collaboration with other governmental entities through a synergistic alignment of related programs. Reinforcing the program through the utilization of complementary initiatives contributed to achieving program objectives without resource constraints. The synergy among agencies was bolstered by optimizing existing social institutions within the community as active program implementers. This, in turn, positively influenced the processes of identification, socialization, and coordination, ensuring their effectiveness. Furthermore, the active involvement of the local community played a pivotal role in addressing challenges and overcoming initial resistance. The application of a persuasive socialization model effectively conveyed the program’s significance in improving the residents’ welfare, thereby fostering acceptance. This collaborative pattern depicts a synergistic model aligning policy maker interests with community needs, characterized by a continuous spectrum of participation and empowerment.

Effects of elevated temperatures’ exposure on the properties of concrete incorporating recycled concrete aggregates

The concrete and its thermal gradient response must be considered when it is subjected to high temperatures. This study examines the impact of exposure to elevated temperatures (500 °C, 700 °C, and 1000 °C) on concrete's physical and mechanical properties incorporating recycled concrete aggregates (RCA). It emphasizes substituting RCAs for natural coarse aggregate (NCA) at 20%, 40%, 60%, 80%, and 100%. The intended behavior is post-heating; a cold sample serves as a control. The evolution of graduating temperature in the muffle furnace is similar to the ISO curve in a fire. The data analyzed indicate that a temperature rise affects the characteristics of recycled aggregate concrete (RAC). A heating level of 500 °C does not significantly affect the initial resistance, which is not the situation at temperatures of 700 °C and 1000 °C. Regarding residual strength, the concrete with 40% RCAs concrete performs quite well. At 700 °C, its strength loss in compressive strength is 24.4%, whereas the control concrete is 29.8%. Mass loss, capillary water absorption, water-accessible porosity and non-destructive tests reveal that elevated temperature damages RAC. Lastly, XRD, TGA, and SEM microstructural analyses are employed to interpret the fundamental mechanisms of heated RAC due to temperature changes.

Reducing teachers' resistance to reciprocal peer observation

Despite the evidence supporting reciprocal peer observation (RPO) for teacher professional development, extant literature has reported that teacher resistance is a barrier to its implementation. Few studies have analysed the variables that moderate resistance to RPO. Based on data from 394 in‐service teachers who participated in an RPO intervention, three aims are addressed: (1) to examine pretest‐posttest differences in resistance to RPO, (2) to analyse the effect of demographic variables and perception of school support in initial resistance to RPO, and (3) to analyse the effect of demographic variables and perception of school support and role performance in final resistance to RPO, after controlling for initial resistance. The Teachers' Resistance to Reciprocal Peer Observation Scale was validated and used as pretest‐posttest. Student's paired sample t‐test was carried out to compare the two scores, and linear regression was used for the second and third aim. Firstly, results show a significant decrease in resistance to RPO. Secondly, initial resistance to the observer and observee role is moderated by teaching experience and feeling properly trained, with additional variables moderating resistance towards being observed (i.e., gender, being part of the school management team, prior experience, school time arrangement). Thirdly, final resistance to both roles is moderated by initial resistance, teaching experience, and variables referring to judging oneself and the partner as capable of successfully participating in the intervention. Limitations and implications for research and practice are discussed. The changes in the quality of teaching that RPO may generate are contingent on reducing teacher resistance.

A SiC membrane resistance recovery methodology based on dynamically dust cake layer analysis

Filter cake-induced resistance is a significant contributor to energy consumption in dust filtration processes. This can be optimized by adjusting inlet gas composition, membrane characteristics, and back-flushing parameters. In this study, calcium carbonate (CaCO3) dust with varying hygroscopicity was utilized to investigate the evolution mechanism of the filter cake on SiC membranes under different humidity conditions. The interacting force between particles and between the cake and membrane were analyzed to elucidate the fragmentation mechanism of the cake. It was observed that particles at higher relative humidity (increased RH from 40 % to 85 %) tend to form a more loosely packed cake (hydrophilic filter cake porosity and hydrophobic filter cake porosity increased from 70.8 % to 80.5 % and from 61.4 % to 69 %, respectively) with greater fragility (reduced cohesive force). This characteristic is advantageous for efficient backflushing operations. The strong adhesion between the filter cake and membrane hindered the recovery of the initial filtration resistance. For SiC membrane, the optimized back-flushing parameter is reservoir pressures of 0.2 and 0.15 MPa and pluse-jet intervals of 40 min to hydrophilic and hydrophobic dusts, respectively.

Development of Graphite Anodes from Coal Derived Carbon

As demand for energy storage expands, securing reliable supply-chains for raw battery materials is critical in mitigating the threats of delayed manufacturing and inflated manufacturing costs. These issues have pushed researchers and industry to consider alternative sources for traditional lithium-ion battery materials, such as graphite. Commonly available sources of graphite for Li-ion anodes include natural graphite and petroleum coke derived synthetic graphite. While many carbon sources have been studied, most require complicated processing and result in sub-par graphite anode materials. This talk highlights raw coal and coal derived materials as promising graphite sources thanks to their abundance of sp2 hybridized carbon, resulting in simpler processing, and low material costs.We show that coal derived graphite can be implemented as a lithium-ion anode, however, many chemical, microstructural, and morphological considerations are necessary to compare with commercial graphite performance. Key topics of this talk include i) the processing steps necessary for achieving high-performing coal-derived graphite, ii) chemical, microstructural, and morphological graphite characterization, and iii) comparative performance of coal-derived graphites and commercial graphite as lithium-ion anodes. Characterization of the anodes’ performance includes gravimetric capacity, initial capacity loss, coulombic efficiency, internal resistance, intercalation energetics, and pseudo-open circuit potential characterization. Emphasis is placed on the careful consideration and effects of fundamental anode properties (particle size, surface area, etc.) because they are crucial in determining the viability of alternative graphite sources for lithium-ion battery anodes.

Study of flashlamp annealing to promote crystallization of indium tin oxide thin films

The use of flashlamp annealing as a low-temperature alternative or supplement to thermal annealing is investigated. Flashlamp annealing and thermal annealing were conducted on 100 nm thick indium tin oxide (ITO) films deposited on glass to compare the properties of films under different annealing methods. The ITO samples had an average initial sheet resistance of 50 Ω/sq. After flashlamp annealing, the sheet resistance was reduced to 33 Ω/sq only, while by thermal annealing at 210 °C for 30 min, a sheet resistance of 29 Ω/sq was achieved. Using a combination of flashlamp annealing and thermal annealing at 155 °C for 5 min, a sheet resistance of 29 Ω/sq was achieved. X-ray diffraction analysis confirmed that flashlamp annealing can be used to crystallize ITO. Flashlamp annealing allows for low-temperature crystallization of ITO on a time scale of 1–3 min. Through electrical and optical characterizations, it was determined that flashlamp annealing can achieve similar electrical and optical properties as thermal annealing. Flashlamp offers the method of low-temperature annealing, which is particularly suitable for temperature sensitive substrates.

Effect of infill walls on progressive collapse behavior of self-centering precast concrete frame

To study the effect of infill walls on the progressive collapse resisting-performance of self-centering precast concrete (PC) frame structures, three 1/2 scaled, two-span and two-story self-centering PC frame specimens with and without infill walls were tested under quasi-static pushdown loading regime. The test results showed that the failure modes of self-centering PC frames were governed by concrete cracking and local spalling at the beam ends under progressive collapse scenario. Compared with self-centering bare frame, the presence of infill walls provided additional load path, thereby reducing the concrete damage at the beam ends to some extent. The full infill walls with lower strength could still increase the initial stiffness and peak resistance of self-centering bare frame to 2.47 times and 1.33 times, while the infill walls with 20% opening ratio could increase to 2.21 times and 1.19 times, respectively. Nevertheless, the infill walls also reduced the self-centering capacity of the structures. Numerical analyses further indicated that the magnitude of prestress force of steel strands between beams and columns, the strength of bed joints as well as the width of infill walls had a great effect on the progressive collapse of self-centering infilled frames. Finally, based on numerical results, a reduction factor formula was proposed to quickly estimate the structural resistance of self-centering infilled frames with different opening ratios.

Energy evolution analysis of heat-treated hydrated shale

To verify the effect of hydrated shale treated by different heat treatment conditions (including heating temperature, heating rate and holding time) on shale gas exploitation efficiency. In this study, uniaxial compression tests were carried out on shale treated under different conditions, and the energy evolution in the process of shale deformation and failure was analysed. According to the energy dissipation and energy accumulation in the process of deformation and failure, the initial porosity, deformation resistance and rock strength of shale sample are discussed and analysed. The results indicate that after high-temperature heating treatment, the initial porosity, ability to resist deformation during elastic deformation stage, and brittleness characteristics of hydrated shale are all improved. The total input energy decreases by 23.16 %, and the peak dissipated energy decreases by 45.89 %, while the proportion of elastic strain energy to total energy in the compaction stage increases by 31.58 %. After thermal treatment, the hydrated shale exhibits increased initial damage, increased rock porosity, and enhanced ability to resist deformation. Therefore, high-temperature heat treatment of hydrated shale is conducted before shale gas exploitation, which enhances both the extraction efficiency and safety during the extraction process. This method is theoretically feasible.