Experimental Test Methods Research Articles

RAdam-Backpropagation-Based Model for Predicting Propped Fracture Conductivity

Summary Hydraulic fracturing is an effective method for enhancing both the initial reservoir production and ultimate recovery. Nevertheless, the conductivity of proppant fractures is a pivotal factor in the optimization of fracture designs within the context of fracture modification. Experimental testing methods for proppant fracture conductivity are costly and time-consuming, and the physical model is excessively complex and incomplete to account for all the influencing factors, resulting in low computational efficiency. A backpropagation neural network (BPNN) model was constructed using the RAdam optimization algorithm to identify a more efficacious method for predicting the conductivity of proppant fractures. The model was used to predict the fracture conductivity of two data types pertaining to the experimental data on the conductivity of geothermal and volcanic reservoirs. The prediction model is enhanced for three key areas. First, an isolated forest algorithm is used to assess and discard anomalous data points. Second, the objective function is optimized by employing the RAdam optimization algorithm, which has the advantages of both Adam and stochastic gradient descent (SGD). This guarantees rapid convergence and prevents the initial training phase from converging to a locally optimal solution. Moreover, this approach enhances the stability of the model training process. Finally, the rectified linear unit (ReLU) activation function may result in issues related to neuronal activity, including the potential for its disappearance. This study addresses this problem by employing the Kaiming initialization method. The experiments used a series of evaluation metrics, including the mean square error and coefficient of determination, to assess the predictive performance of the two data sets in the two distinct models. The experimental results indicate that the BPNN with RAdam optimization is a more effective approach for data pertaining to volcanic and geothermal reservoirs. Moreover, the prediction of the geothermal reservoir data is more precise than that of the volcanic reservoir data. This model can be used for rapid predictions based on existing fracture conductivity data, which can better guide the design of fracture modifications and is of great importance.

Development of a test method for adhesive tapes certification and application

Sufficient airtightness of a building envelope is important both to ensure the overall energy efficiency of a building and to prevent moisture-related damage to the structure. Air leakages typically occur in the context of joints and perforations in vapor barriers installed inside walls and roofs. It is essential to give proper attention to details to achieve sufficient airtightness of building envelopes and joint’s durability. Sealing such building details with durable solutions is essential for ensuring sufficient airtightness overall. In recent years, adhesive tapes have increasingly been used for this application. However, there remains uncertainty regarding its performance in the long-term. The study offers an overview of the current state of the art by incorporating findings from a literature review including an analysis of established methods currently being used for evaluation of tape joint durability, as well as other experimental test methods. The aim of research presented in this paper is to contribute to the development of a test method with sufficient accuracy, reproducibility, and repeatability to be used in the development and certification of tape products and systems. Although the method in development displays limitations in terms of reproducibility, it is regarded as a promising concept. Through further development, the method is believed to be suitable for potential integration into wider evaluation programs addressing adhesive tape durability, supplementary to existing methods.

Design and Development of a Smart Trash Bin to Minimize Odor from Household Waste Based on the Internet of Things

The problem that occurs is that household waste continues to increase along with the development of population and the number of increasingly dense settlements. The existence of this household waste is of concern to the community and the government because it can cause various negative impacts. Based on the results of observations of the existing trash cans, the accumulation of household waste is the source of this unpleasant odor. Smell is connoted as something that tends to disturb comfort, and gives the impression of being unclean and the like, such as fishy, rotten, urine, rancid, and so on. The smell of burning garbage is also dangerous because it contains H2 which reduces the amount of oxygen in the air. This study aims to prevent the occurrence of unpleasant odors from garbage. The tool will be designed using the NodeMCU microcontroller with website-based monitoring and Whatsapp notifications automatically when the trash can is full and automatic deodorizing powder spraying according to the concentration of gas released by the stench. This study uses the Experimental and Comparative Testing method in designing an IoT-based Smart Trash Bin tool and conducting tests on the built system and comparing the test results with the expected system. The results of this study indicate that the Smart Trash Bin tool can work and function as expected, namely being able to minimize the unpleasant odor emitted by the trash can and being able to monitor the sprinkling of deodorizing powder, the status of the height of the trash can and can provide notifications both automatically and manual to officers through the website.

Characterization of aircraft landing impact loads: Effects on vertical tire-pavement contact characteristics and pavement performance

The comprehensive understanding of the mechanistic behavior of airport pavements under aircraft landing loads is essential for ensuring safety and durability. Addressing the limited understanding on the interaction between aircraft landing gear and airport pavement during landing, this study proposed a measurement method for the vertical dynamic contact characteristics of tire-pavement interface and internal dynamic responses based on a laboratory dynamic test device. This involved the experimental design and testing method for the dynamic characteristics of landing gear landing loads, utilizing the Tekscan pressure measurement system to evaluate the vertical dynamic contact characteristics between the aircraft tires and pavement during landing. Through comparative analysis with the static results, the study revealed the importance of landing load measurements for mechanical response analysis and durability design of airport pavements. Additionally, the study investigated the dynamic response of airport pavements under different simulated aircraft landing speeds and weights, and further quantified the impact effects of aircraft landing loads on airport pavements. The results show that the vertical tire-pavement contact characteristics under landing impact are significantly different from those under static conditions, and need to be considered. The proposed quantitative equations with acceptable good fitting effect provided more accurate and efficient vertical load inputs for numerical simulation and durability design of airport pavements, which laid the foundation for understanding the failure mechanisms of airport pavement and enhancing the safety of aircraft and airport operation.

Effect of amygdala on the pore-crack structure and mechanical properties of Permian tuff and breccia during hydration

The Permian volcanic rocks in the Sichuan Basin are rich in oil and gas resources. However, during volcanic rock exploitation, the working fluid fully contacts with the volcanic rocks, and hydration reaction will occur, which destroys the pore structure of the rock, makes the rock layer loose and fragile, increases the risk of wellbore collapse, and causes the loss of volcanic rock production. However, the reasons for the change of pore structure of volcanic rocks after hydration and the understanding of the hydration mechanism of volcanic rocks are not clear. Therefore, this paper uses microscopic and mechanical experimental testing methods combined with digital core technology to study the changes of pore-crack structure, amygdale structure and mechanical characteristics of Permian tuff and breccia in Sichuan Basin before and after hydration. The research results show that during the hydration process of volcanic rocks, pores, cracks, and amygdales are transformed into each other. The hydration process of the volcanic rocks is characterized by the disappearance of isolated pores, the generation of small cracks, and the generation and transformation of new pores into amygdales. Amygdales also have an important impact on the mechanical properties and hydration of volcanic rocks. When the content of amygdales in volcanic rocks is high, the rocks are more prone to breakage. In addition, amygdales promote the hydration reaction of volcanic rocks, and the size and number of amygdales determine the strength of volcanic rock hydration ability. When the content of amygdales in the rock is higher, the rock is more prone to hydration reactions. Therefore, in the process of gas reservoir development, understanding the distribution and characteristics of amygdale is helpful to optimize the composition of the working fluid and enhance drilling technology. It aims to maximize the productivity gas wells.

Robust biomimetic strain sensor based on butterfly wing-derived skeleton structure

A biomimetic strain sensor was designed and constructed based on Ir nanoparticles-modified multi-wall carbon nanotubes (Ir NPs@MWCNTs) and parallel Pt layer/dragon skin with carbonized butterfly wing patterns. This sensor exhibits high gauge factor (∼515.4), extensive tensile range (0%–96%), and swift response (∼300 ms), especially remarkable stability up to 60 000 cycles. The work mechanism has been proposed based on the experimental test and finite-element method. Some important applications such as human motion and micro-expression recognition have been confirmed using 3 × 3 flexible biomimetic sensor array.

Pot Skirt Configuration on the UB-03 Biomass Stove: Taguchi Approach Optimization

A biomass stove is a technology that can utilize biomass fuel as an alternative energy source. This stove is considered effective for saving fossil energy because it uses fuels such as wood, waste, and plants so that it can reduce the effects of global warming because it can minimize the emissions it produces. In its technological development, UB-03 is a biomass stove product with compact construction and affordable prices for rural communities. However, there needs to be an increase to produce more efficient performance. In this case, additional configurations in the form of a pot skirt can be used to increase the efficiency of the biomass stove. The pot skirt is a device that focuses the fire’s direction on the load to minimize wasted heat and increase the efficiency of the biomass stove. This study used the Water Boiling Test (WBT) method for experimental testing. In addition, the Taguchi method was used to analyze the data obtained. This study aims to determine the optimum conditions of the biomass stove with the addition of a pot skirt using the Taguchi method with orthogonal array L9 (33) with three factors, namely angle (64°, 65°, 66°), number of holes (9,10,11) and hole diameter (0.8 cm, 1 cm, 1.2 cm). The results of this study indicate that the optimal configuration obtained is by adding a pot skirt at an angle of 65° with 9 holes and a hole diameter of 1 cm, where the highest efficiency value is obtained, namely 21.19%.

Enhancing MPPT efficiency in PV systems under partial shading: A hybrid POA&PO approach for rapid and accurate energy harvesting

Partial shading in operational environments introduces multiple peaks in the output characteristics of photovoltaic (PV) systems, presenting significant challenges to energy harvesting. This study introduces a novel meta-heuristic algorithm, termed POA&PO, which aims to address the maximum power point tracking (MPPT) issues in PV systems. The algorithm capitalizes on the global search capability of the POA method to quickly pinpoint the range with the maximum power, followed by the fast convergence of the PO method to ensure both rapidity and accuracy of the solution. Extensive simulation tests, conducted in MATLAB/SIMULINK, have demonstrated the efficacy of the POA&PO algorithm, achieving an average tracking efficiency of 99.97 % with a convergence time of 0.3 s in step response tests; under the EN50530 test standard, the algorithm also showed sustained and stable tracking of ramp signals. Moreover, practical testing utilizing a new, low-cost indoor PV simulator confirmed the algorithm’s high performance under controlled conditions, yielding an average tracking efficiency of 97.03 % and a convergence time of 0.18 s. This paper highlights the capacity of the developed algorithm to reliably, accurately, and swiftly achieve high energy transfer efficiency. Additionally, the innovative and economical experimental testing methods employed are emphasized, contributing to the practical applicability and cost-effectiveness of the proposed solution.

A Novel Fractal Model for Contact Resistance Based on Axisymmetric Sinusoidal Asperity

In this paper, a novel fractal model for the contact resistance based on axisymmetric sinusoidal asperity is proposed, which focuses on the resistance characteristics of the rough interface at a microscopic scale. By introducing the unique geometric shape of axisymmetric sinusoidal asperity, and combining it with a three-dimensional fractal theory, the micro-morphology characteristics of the rough interface can be characterized more precisely. Subsequently, by conducting a theoretical analysis and numerically solving the deformation mechanisms of asperities on the rough interface, a refined model for contact resistance is constructed. This research comprehensively employs theoretical analysis, numerical simulation, and experimental testing methods to deeply explore the current transmission mechanisms during the contact process of the rough interface. The findings suggest that the proposed model is capable of precisely capturing the intricate interplay of various factors, including contact area, contact load, and material properties, with the contact resistance. Compared to the existing models, the presented model demonstrates significant advantages in terms of prediction accuracy and practicality. This research provides an important theoretical basis and design guidance for optimizing the electrical performance of the rough interface, which has great significance for engineering applications.

Novel auxetic metamaterials inspired from geometry patterns of an Iranian Mosque with improved energy absorption capability

Recent developments in auxetic metamaterials have positioned them as highly effective energy absorbers, offering superior energy absorption and specific energy absorption (SEA) properties. Meanwhile, the fascinating geometric patterns and motifs found in historical arts have emerged as a valuable source of inspiration for designing innovative auxetic unit cells. This research proposes a novel auxetic unit cell inspired by the geometric patterns exhibited in the Isfahan Jameh Mosque in Iran. Two distinct auxetic structures are designed with different arrangements of the proposed unit cell and fabricated via the fused deposition modeling (FDM) additive manufacturing technology. Their negative Poisson’s ratio (NPR), energy absorption capability, and SEA are evaluated through both experimental testing and finite element method (FEM). The comparative analysis of the results shows that the designed structures exhibit significantly enhanced energy absorption compared to the other two different re-entrant auxetic structures. Consequently, these novel auxetic structures hold great promise in replacing conventional re-entrant structures as highly efficient energy absorber devices.

International inter-laboratory comparison of solar heat gain coefficient of building-integrated photovoltaic modules results of tests with or without power generation and tests with PV cell coverage ratios

The solar heat gain coefficient is one of the important indicators to evaluate the performance of the building envelope components. In a BIPV module, secondary heat transfer to the indoors is reduced, compared to conventional glazing, due to the shielding effect of the PV cells and energy conversion by power generation. There is a difference in SHGC between power-generating (MPP) and effectively open-circuit (OC) states. In this paper, in order to prepare a calorimetric SHGC evaluation methodology for BIPV modules, we documented the current status of the experimental calorimetric test methods and test apparatus adopted by test laboratories in four different countries and identified the differences. Differences between the test laboratories were found in to the applied test methods, solar simulator types, spectral distributions, DC or AC power supplies for the solar simulator, irradiation inhomogeneity on the light-receiving surface of the test sample, temperature conditions between the test chamber and the metering box, and surface heat transfer coefficients. Especially, the round-robin test results obtained in an interlaboratory comparison clarified that the differences in the characteristics of the Calorimetic Hot Box and the Heat Flux Metering methodologies with a cooled plate, the differences in irradiation inhomogeneity on the light-receiving surface of the test sample and differences in surface heat transfer coefficients significantly affect the SHGC evaluation for BIPV modules. In addition, for the SHGC test in the MPP state, it was confirmed that an absolute SHGC reduction effect of 0.02 to 0.04 was obtained for a PV laminate with 81 % cell coverage, for all SHGC test methods and test apparatus. Pe characterises the effect of converting part of the sunlight absorbed by the PV cell into electric power and extracting it from the BIPV module, reducing the heat re-radiated indoors compared to the OC state. Due to this mechanism, the reduction effect Pe always occurs during power generation, regardless of the type of PV cell technology and whether the PV cells are opaque or transparent. In addition, the decrease in SHGC for a given glazing configuration was found to be proportional to the increase in PV cell coverage ratio. SHGC tests with four different cell coverage ratios confirmed that the relationship between PV cell coverage ratio and SHGC is linear to a high degree of accuracy when no electric power is extracted (OC state), provided that the incident radiation is spatially homogeneous. The results obtained will be useful when proposing a calorimetric SHGC evaluation methodology for international standardization, as they document the differences due to a range of test facilities and testing conditions, differences caused by power generation and extraction, and the effect of varying PV cell coverage ratios. The insights gained were valuable in identifying which aspects of test methodology and boundary conditions must be specified with particular attention to detail when calorimetric testing standards are extended to explicitly address the SHGC determination of BIPV modules.

Fabrication, Modeling, and Testing of a Prototype Thermal Energy Storage Containment

Abstract Increasing penetration of variable renewable energy resources requires the deployment of energy storage at a range of durations. Long-duration energy storage (LDES) technologies will fulfill the need to firm variable renewable energy resource output year round; lithium-ion batteries are uneconomical at these durations. Thermal energy storage (TES) is one promising technology for LDES applications because of its siting flexibility and ease of scaling. Particle-based TES systems use low-cost solid particles that have higher temperature limits than the molten salts used in traditional concentrated solar power systems. A key component in particle-based TES systems is the containment silo for the high-temperature (>1100 ∘C) particles. This study combined experimental testing and computational modeling methods to design and characterize the performance of a particle containment silo for LDES applications. A laboratory-scale silo prototype was built and validated the congruent transient finite element analysis (FEA) model. The performance of a commercial-scale silo was then characterized using the validated model. The commercial-scale model predicted a storage efficiency above 95% after 5 days of storage with a design storage temperature of 1200 ∘C. Insulation material and concrete temperature limits were considered as well. The validation of the methodology means the FEA model can simulate a range of scenarios for future applications. This work supports the development of a promising LDES technology with implications for grid-scale electrical energy storage, but also for thermal energy storage for industrial process heating applications.

Analisis Redaman Sistem Vibrasi Paksa Satu Derajat Kebebasan Pada Simple Vibration Apparatus

Vibration testing in the field of mechanical engineering has an important role in planning and maintaining machines to determine whether the design is safe and suitable for application. Newton's second law is a reference for back-and-forth movement around equilibrium both within the system and from outside the system which affects the machine itself, if the frequency of stimulation is equal to one of the system's natural frequencies, then resonance occurs, and dangerously large oscillations, resonance can cause damage to the system. The solution to avoid excessive resonance requires a damper. Forced vibration oscillations are applied by excitation using an unbalanced mass installed on a DC motor unit, the response is a mass deviation to obtain oscillations or time relationships with amplitude, the natural frequency of the system, mass-spring deviation, and characteristics of vibration. This activity aims to analyze the effect of the vibration amplitude of a forced vibration simulator under conditions without damping and using damping. The experimental test method was applied to a forced vibration system with one degree of freedom with an oil and air damper in a simple vibration apparatus simulator, 2 types of unbalanced masses, regulated by rotation up to 500rpm, tested under conditions without a damper, using an oil and air damper. The results of the activity showed that the air-dampening media can limit greater amplitude compared to the oil-dampening media.

Prediction and optimization of pure electric vehicle tire/road structure-borne noise based on knowledge graph and multi-task ResNet

Pure electric vehicles (PEVs) offer a significant advantage in their lower interior noise levels compared to traditional combustion engines, making them increasingly popular among consumers. However, the absence of engine noise has brought attention to other sources of noise, particularly tire/road structure-borne (TRS) noise, which significantly impacts the sound quality of the PEV interior and passengers’ psychological comfort. To address this issue, numerous studies have employed simulation analysis, data-driven approaches, and experimental test methods for the prediction and optimization of TRS noise. Nevertheless, the optimization and rectification of TRS noise problems present recurring challenges and difficulties due to the involvement of numerous variables and the weak correlation between TRS noise and vibration. In response to these challenges, this paper introduces a novel approach that combines knowledge graph and multi-task ResNet for predicting and optimizing PEV TRS noise. The proposed method has been experimentally validated and has demonstrated superior effectiveness and robustness compared to three commonly used prediction and optimization methods. The paper’s main contributions are twofold: Firstly, it introduces a novel mechanism that fuses mechanism-driven and data-driven approaches by utilizing a knowledge graph to establish dependency and correlation relationships among TRS entities. This fusion, together with the multi-task ResNet, enhances the interpretability of the solution results while improving computational efficiency. Secondly, it introduces a multi-task ResNet prediction method, named TCGC-ResNet, which incorporates a Task-Conditional Gate Control (TCGC) technique. By explicitly separating shared components from task-common components and implementing a gate control mechanism, TCGC-ResNet enables the gradual extraction and separation of task conditional information knowledge. These advancements contribute to a more comprehensive and effective solution for predicting and optimizing PEV TRS noise.

The Effect of Balance Training on Physical Motor Functions TO 11-12 Year Old Female Football Players

The aim of this study was to investigate the effect of balance training on the physical motor function of adolescent female football players. Thirty female football players aged 11-12 years were selected from Ausheng Football Club as the study subjects, and they were divided into a test group and a control group of 15 each using experimental testing and mathematical statistics methods. The experimental group received balance training intervention for a period of 5 weeks while the control group did not receive any intervention. The Y-Balance test and FMS test were used as assessment indicators to evaluate the balance and body movement function of the athletes respectively. Differences in performance between the two groups before and after training were compared and the relationship between balance ability and physical motor function was analyzed by methods such as paired samples t-test and independent samples t-test. The results showed that compared with the control group, the experimental group showed significant improvement in all balance indicators, especially in medial back and overall balance. In addition, the experimental group showed significant improvement in hurdle stride, linear lunge, and rotational stability indicators. The overall motor function of the experimental group improved significantly as assessed by the Functional Movement Screen (FMS), which indicated that the balance training was very effective. The Y-balance test further confirmed that the experimental group showed a substantial improvement in balance, while the control group showed little change. In addition, the results of the Y-balance test showed a moderate positive correlation with the results of the FMS test, suggesting a relationship between balance and functional movement. These findings emphasize the positive impact of balance training on the physical motor function of young female footballers, demonstrating the importance of balance training in motor development and injury prevention.

PENGARUH LAMA WAKTU TAHAN NORMALIZING PADA BAJA ST 41 PENGELASAN FRICTION WELDING TERHADAP SIFAT MEKANIS

The development and application of science and technology, especially in the industrial world, is currently experiencing very rapid progress, especially in the world of welding. Welding is the process of joining two or more metal parts using heat energy. In the current era, welding developments are increasingly developing, such as liquid welding, resistance welding, solid welding, and forging welding. For solid welding, there are friction welding and cold welding. The joining process using friction welding involves friction factors, pressing force, and surface quality. To improve the mechanical properties of steel after welding, Normalizing heat treatment is carried out, namely a heat treatment process on steel which aims to refine the grain, homogenize the structure and obtain steel with mechanical properties as desired, or called normalization. This research method uses the Experimental Testing method. This sample was obtained from the normalizing friction welding process which was tensile tested, namely samples with varying holding times of 15 minutes, 30 minutes and 45 minutes with an engine speed of 2100 rpm and a pressure of 35 MPa with tensile testing of the material and microphotographs. The results of the friction welding research are as follows. The normalizing holding time of 15 minutes produces a maximum tensile stress value of 325.16 N/mm2, the fracture that occurs is in the form of a ductile fracture, the normalizing holding time of 30 minutes produces a maximum tensile stress value of 327.66 N/mm2, the fracture that occurs is in the form of a fracture ductile, the normalizing holding time of 45 minutes produces a maximum tensile stress value of 329.53 N/mm2, the fracture that occurs is in the form of a ductile fracture. The long holding time of normalizing will increase the tensile strength of the steel and tensile test fractures mostly occur in the weld area

Experimental Method to Determine the Draping Behavior of Auxiliary Materials for the Vacuum Bagging of CFRP Parts on Doubled-Curved Surfaces

The production costs of aircraft primary structures made of carbon fibre reinforced polymer (CFRP) are significantly higher than for comparable metal-based structures. Today substantial effort is made to achieve a sufficient reproducibility and parts’ quality in manufacturing processes of CFRP structures. Especially the sub process vacuum bagging for infusion processes is still expensive. One of the reasons is the complex positioning of the flexible auxiliary materials which have to be stacked on the preform. During the positioning on doubled-curved surfaces these materials tend to form wrinkles, which can lead to defects of the composite part. Yet, a defined description of the wrinkling behavior of the auxiliary materials on doubled-curved surfaces does not exist. In this work a characterization of the wrinkling behavior on doubled-curved surfaces is investigated for the auxiliary materials of the Vacuum Assisted infusion Process (VAP®): release film, perforated peel ply, flow media, membrane and vacuum foil. Therefore, an experimental test method is derived similar to established hemisphere deformation test methods. The wrinkling behavior for the specific VAP auxiliary materials is empirically determined on differently curved surface geometries. It is shown that the draping behavior can be characterized by partial wrinkle-free surfaces between the wrinkles. A material specific threshold is derived to determine the appearance of wrinkles. The work shows that a characterization of the draping behavior of auxiliary materials on doubled-curved surfaces is possible. With the gained knowledge the potential for an increase of the vacuum bagging reproducibility is given.

Randomised nano-/micro- impact testing – A novel experimental test method to simulate erosive damage caused by solid particle impacts

A novel randomised nano-/micro-scale impact test method has been developed to experimentally simulate particulate erosion where statistically distributed impacts with defined energy occur sequentially within the test area. Tests have been performed on two brittle glasses (fused silica and BK7) to easily highlight the interaction between impacts, as well as on two ceramic thermal barrier coating systems (TBCs, yttria stabilised zirconia, 7YSZ, and gadolinium zirconate, GZO) that experience erosion in service. Differences in erosion resistance were reproduced in the randomised impact tests, with GZO less impact resistant than 7YSZ, and BK7 significantly worse than fused silica. The impact data show that erosion resistance is influenced by different factors for the glasses (crack morphology, longer-length interaction of radial-lateral cracks in BK7 vs cone-cracking in fused silica) and TBCs (fracture toughness).

IN VIVO ACUTE TOXICITY TEST OF ALOIN EXTRACT ON CHICKEN WHITE MENCITES (Mus musculus)

Aloin has many benefits potential as a medicine. However, it is necessary to carry out toxicity tests on experimental animals as a pre-screening test. Toxic effect parameters were seen from changes in body weight, tremors, convulsions, salivation, weakness, walking backward, walking on the stomach, death, and levels of SGOT and SGPT in experimental animals. This study aims to evaluate the in vivo acute aloin toxicity test results in mice (Mus Musculus) regarding potential toxic symptoms and animal death. A sample of 27 mice were separated into three groups for this investigation: the control group, the treatment group I at a dose of 2500 µg/kg BW, and the treatment group II at an amount of 5000 µg/kg BW, and 5 mice in the preliminary test. This study employed a laboratory experimental test method using a pre-post control group design study. Based on observations of experimental animals, it concluded neither the preliminary test nor the toxicity test revealed any toxic signs. Neither the initial test nor the toxicity test resulted in any observed animal fatalities. Before and after aloin administration, changes in body weight were significantly different. Treatment group II, treatment group I, and the control group's SGOT levels were classified from highest to lowest, with subsequent values of 22.4 U/L, 21.9 U/L, and 19.9 U/L. The highest value of 35.7 U/L, 32.1 U/L, and 26.2 U/L in the treatment groups II, I, and the control group was used to rank the SGPT levels. There were no toxic symptoms and no mortality in experimental animals, so it can be concluded that aloin did not cause harmful effects in mice, so it was categorized as a pseudo-lethal dose.

Peran Metode Pembelajaran Market Place Activity (MPA) dalam Meningkatkan Hasil Belajar Siswa Mata Pelajaran Fiqih di Kelas VIII MTs Negeri 3 Bekasi

Based on the author's observations of class VIII students at MTs Negeri 3 Bekasi, some students still have low learning outcomes in the Fiqh subject. With this data, it is necessary to improve learning methods in Fiqh subjects. The aim of this research is to find out whether there is a significant difference in improving Fiwih learning outcomes after implementing the Market Place Activity (MPA) method. The method used in this research is the Quasi Experimental Test method. The form of this research design is Nonequivalent Control Group Design, namely research to find the influence of the Market Place Activity method on student learning outcomes in Fiqh subjects in class VIII MTs Negeri 3 Bekasi. In this research, the test was given twice, namely: first, students were given an initial test (pre-test) to determine the extent of students' knowledge in both the control and experimental classes. Second, students were given a final test (post-test) using conventional methods in the control class and using the Market Place Activity method in the experimental class. From the test results, it can be concluded that there has been an increase in learning outcomes for Fiqh Subjects in class VIII at MTs Negeri 3 Bekasi, which was taught using conventional methods, with an average score of 22.74, as well as an increase in student learning outcomes for Fiqh Subjects in class VIII at MTs Negeri 3 Bekasi which is taught using the Market Place Activity method can be seen from the average score of 28.1. Meanwhile, in the T test, there was a difference in the learning outcomes of students in the Fiqh subject in class VIII MTs Negeri 3 Bekasi after the Market Place Activity method was applied. It was seen that the significance was 0.000 < 0.05, so it could be concluded that the Market Place Activity method could improve the learning outcomes of class VIII students. MTs Negeri 3 Bekasi.