Pressure Plate Research Articles

Engagement/Disengagement Characteristics of Pull-Type Diaphragm Spring Clutch for Heavy-Duty Commercial Vehicles

Considering that the clutch cover assembly and driven disc assembly show common effect on the engagement/disengagement characteristics of the pull-type diaphragm spring clutches for heavy-duty commercial vehicles, the diaphragm spring, cushion plate, and friction plate, are thoroughly analyzed in this paper. The A-L method and the micro-element method are used to analyze the mechanical properties of diaphragm spring and cushion plate, respectively. The mechanical characteristics are obtained via numerical simulation, and the deformation and load mechanical characteristics of the cushion plate are verified by experimental tests. According to the relationship between the pressure plate temperature and the friction coefficient of the friction plate, the influence of the change of the friction coefficient on the transmission torque characteristics of the clutch is analyzed. In view of the torque fluctuation in the process of engagement/disengagement, the mathematical model of torsional characteristics is established with consideration of the torsional characteristics of torsional damper. Modeling and simulation of the handling characteristics are carried out to evaluate the influence of the boosting characteristics of the hydraulic operated pneumatic booster on the clutch pedal operating force separation characteristics. Specific tests are also conducted, and the effectiveness of the established models is verified.

Identification of plant soil water and soil aeration corequisites: A management tool

AbstractPlant‐available soil‐water and adequate soil aeration within the root zone are essential corequisites for successful plant growth. Characterization of these two requirements for plant growth is generally done by independent measurements of water and air phase properties and functions in soil, with limited emphasis on their combined effect. This study investigated soil‐water characteristic (SWC) measurements in vadose soil profiles (up to 117‐cm depth) in six pasture soils to examine the combined behavior of soil‐water and diffusion‐controlled aeration within the root zone. The soil moisture measurements were made over matric potentials ranging from −1 to −1500 kPa using tension table and pressure plate apparatus. The van Genuchten model was used to parameterize the measured SWC curve, while the Millington–Quick model was used to derive soil‐gas diffusivity from measured soil physical properties. Based on two simple indices, derived to represent plant‐available soil‐water and soil aeration status at a given moisture content, we propose an assessment matrix, which illustrates how a soil satisfies the corequisites for successful plant growth, as it drains to different matric potentials upon irrigation. Results show a pronounced effect of soil texture and, to a lesser extent, soil structure on satisfying these corequisites. With the aid of the assessment matrix, we observed that loam, sandy loam textures exhibited a good overall performance, while sand, clay loam, and clay soils struggled to meet these corequisites during drainage.

Soil Water Characteristics Curves (SWCC) of Residual Soils Stabilized using Emerging and Novel Bioinspired Technique

The development of unsaturated soil mechanics stemmed from the inadequacies of classical soil mechanics in addressing the partial pore spaces found in real-world soil systems. However, assessing soil parameters under partial saturation is resource-intensive. To streamline this, the Soil-Water Characteristic Curve (SWCC) theory was introduced. Widely applied across geotechnical engineering, water resources, and agriculture, SWCC predicts parameters of unsaturated soil systems. In geotechnical engineering, SWCC is vital for designing systems near the Earth's surface, like slopes, clay liners and foundations. Furthermore, most of conventional soil improvement techniques pose a lot of environmental concerns. thus, emergence of green construction materials widely known as bio mediated and bioinspired soil improvement techniques like Enzymatic induced calcite precipitation (EICP). EICP, an emerging eco-friendly as it employs use of simply chemical compound that reduces carbon footprints, bioinspired technique as it mimics natural forming process, was applied to stabilize tropical soil for SWCC determination. SWCC parameters were derived by subjecting EICP-treated soils at varying concentration of cementation solutions (0 – 1.00 M) using pressure plate method. Results revealed that saturated water content θs, retention water content θr, and air entry value Ψa increased with higher cementation solution concentration. The values of θs, θr, and Ψa improved from of 0.663, 0.23405, and 3.4832 at 0 concentration of cementation solution to 0.701, 0.22864, and 7.7086, respectively upon treatment with 1.00 M cementation solution. Finally, it has been demonstrated EICP is capable of improving the SWCC parameters of residual soil, thus the EICP technique can be exploited in stabilization of residual for construction of compacted clay liner.

Analysis of Thickness Variation in 2219 Aluminum Alloy Ellipsoid Shell with Differential Thickness by Hydroforming

The process of spinning and machining for heavy plates has the problems of a large amount of machining, large springback, and easy cracking. Aiming to address these issues, we proposed a deep drawing forming method for a plate with differential thickness to manufacture an integral ellipsoid component with a thin zone in the middle and a thick zone in the periphery. The plate with a differential thickness was initially produced through machining, followed by the execution of deep drawing deformation. During the deformation process of plates with differential thickness, the thin zone is prone to rupture defects. Therefore, a hydroforming method utilizing an elastic auxiliary plate was adopted to solve this problem. Through mechanical analysis and deep drawing experiments, the influences of hydraulic pressure and elastic auxiliary plate on the distributions of thickness and strain were studied, and the influence of friction on hydroforming was analyzed. The results indicate that increasing the hydraulic pressure and setting elastic auxiliary plates can increase the interfacial friction, reduce the thickness thinning rate, and improve the thickness distribution and deformation uniformity within the thin zone. When the hydraulic pressure is 5.2 MPa and the thickness of the elastic plate is 5 mm, the maximum thickness thinning rate of the ellipsoid shell is 8.8%, which is 34% lower than that of the ellipsoid shell obtained via conventional deep drawing.

Effects of carbon dioxide blasting on hot dry rock reservoirs considering thermal damage

A cutting-edge technique for igniting hot dry rock (HDR) reservoirs is carbon dioxide blasting. The cooling effect of the drilling fluid was taken into consideration during a numerical simulation of the action range of carbon dioxide blasting-induced cracking. A temperature difference was used to determine the reservoir's material properties. Additionally, temperature distribution functions were used to create the temperature field in the reservoir. The blasting load is calculated using the pertinent theories and formulas of explosive blasting, and the process of blasting carbon dioxide to excite the HDR reservoir is modeled using COMSOL. The findings show that several stress concentrations take place during the blasting process. The fracture zone is created by the tensile stress concentration outside of the crushing zone, whereas the compressive stress concentration close to the blast hole creates the crushing zone. Furthermore, the effectiveness of carbon dioxide blasting fracturing would be affected by the beginning temperature and pressure plate thickness. Although the scope of the fracture zone is mostly unchanged, the initial temperature has a significant impact on the blasting crushing zone. The size of the crushing zone, which determines how the blasting fracture zone is distributed, is unaffected by the pressure plate's thickness.

Design and development of an IoT-based trolley for weighing the patient in lying condition.

An immobile patient cannot be weighed on a stand-on weighing machine, i.e., a bathroom scale. They have to get weighed while lying, which is not easy. The main objective of this research is to design a medical apparatus that measures the patient's weight in a lying condition. To achieve this the apparatus is designed as a stretcher to carry the patient in and around the hospital. The stretcher has four load cells to measure the patient's weight; it can bear a weight of 500 kg and has a self-weight of 20 kg. A Microcontroller unit (MCU) is embedded into the apparatus to weigh the patient lying on it. The stretcher comprises the top frame, middle frame, and base frame. The top frame can be detached and mounted back to the middle frame; this will help the medical personnel shift the patients from a medical bed. The middle frame is a plate structure where the four load cells are mounted at the corners of the lower plate. The upper plate functions as a pressure plate on the load cell. The base plate has four heavy-duty wheels that can bear the load. The middle frame and base frame, together, form a single structure, giving mobility to the structure. A control panel is employed with reset, tare, and on-off buttons to control the embedded platform. The LCD panel on the side of the apparatus shows the weight when the patient is placed on top of the apparatus. A prototype trolley equipped with a wireless data logging system was tested on 10 healthy participants. The device accurately measured weight within ±50 g across a scale range of 2-140 kg, with data captured every 30 s over a 5-min testing period. Wireless communication was successfully demonstrated over a 100-m range. The important add-on feature of this work is the apparatus is connected to the internet, transforming it into an IoT-based medical device.

Many-body dissipative particle dynamics analysis: Generation and stability of bulk nanobubbles under the influence of pressure

Bulk nanobubbles can be generated through various methods such as ethanol-water exchange, vacuum method, and pressure method. However, the mechanisms and stability of nanobubble generation under pressure are unknown. In this study, a new pressure control method is proposed by combining the pressure control advantages of dissipative particle dynamics (DPD) with molecular dynamics (MD). The effectiveness and rationality of the new pressure control method are validated by using system temperature and pressure as indicators. Furthermore, based on the Ferralo experiment, the experimental process is decomposed and abstracted into specific simulation processes to investigate the effect of pressure on the stability of bulk nanobubbles. The results show that the pressure changes in the two-phase flow can be well controlled by the pressure plate and the pressure regulator based on DPD. A large amount of bulk nanobubble generation occurs during depressurization in a confined space, while pressurization leads to the dissolution of unstable bulk nanobubbles, while stable bulk nanobubbles persist.

Horseshoe effects on equine gait-A systematic scoping review.

To provide an overview of available research about effects of horseshoes on equine kinetics and kinematics. The terms, "horse/equine," "hoof," "shoes/horseshoes," "kinetics," and "kinematics" were searched in PubMed, Web of Science, Center for Agriculture and Bioscience International, and United States Department of Agriculture National Agricultural Library for manuscripts from first availability to 2024. Independent reviewers used preferred reporting items for systematic reviews and meta-analyses guidelines to map and extract evidence-based data from sources. Metrics included participant demographics, research methods, major findings, and study limitations. Knowledge gaps were also identified. A total of 46 studies were included. Most utilized non-lame horses to compare original shoe designs or modifications to unshod or a standard open-heel shoe. Horse demographics and gait, study design and outcome measures varied widely. Prevalent data collection equipment included force platforms and pressure plates, wearable force measuring technology, and videography. Many studies reported shoeing effects on limb forces and motion, but there was little consensus among unrelated studies. Common limitations included insufficient data resolution, no randomization, small sample size, single breed, and outcome measures specific or unique to the study. Knowledge gaps included data collection from all limbs and the impact of conformation and limb and hoof morphology and health condition on outcomes. Information from manuscripts that met inclusion criteria confirmed distinct, variable effects of shoe characteristics on equine gait parameters. Details from published work can serve as resource for clinical decisions and to guide standardization among investigations on shoe configuration effects on equine motion.

Model Modification of the Soil–Water Characteristic Curve of Unsaturated Weak Expansive Soil

This study evaluates the impact of compaction on the soil–water characteristic curve of unsaturated remodeled weakly expansive soils by assessing changes in soil pore structure resulting from variations in compaction. The remodeled weakly expansive soil in the Xinjiang Hami area is taken as the research subject to investigate how compaction affects microscopic pore structure using mercury intrusion testing. Subsequently, mercury intrusion porosimetry is employed to examine pore structure and distribution patterns at different dry densities. Based on the capillary principle and experimental methods (filter paper method and pressure plate method test), modified soil–water characteristic curves are obtained by fitting them with a three-parameter model law. The results indicate that higher dry density leads to an increased air intake value and significantly reduces the total volume of large pores within samples. Both the Fredlund and Xing model and the three-parameter model effectively capture the influence of initial dry density on the development pattern of the soil–water characteristic curve.

POWER ACCUMULATOR FOR STABILIZATION OF THE PRESSING PRESSURE OF THE CORE OF A POWERFUL TURBOGENERATOR WITH BUILT-IN METER

In this paper present described features of stabilization and restoration of pressing force of the stator core of a powerful turbogenerator (TG). Weakening of the pressing forces is the cause of a number of negative phenomena, such as increased vibration and loosening of the core sheets with their subsequent destruction (cracking), which is often the cause of generator damage. It is shown that to assess the state of the pressing force in the core of the TG stator, force meters in the clamping prisms of the core, built into the design of the power accumulator (PA) for stabilizing the pressing force of the core, can be used. The design of the package of disc springs used in PA consists of a package of plate springs and allows to stabilize the pressure in the stator core of a powerful TG to a given level without additional control with probes and fixation by tightening the adjustment nuts. Describes the advantages and features of using PA with a package of disc springs for pressure stabilization, installed under the tightening nuts or instead of them on the threaded ends of the tightening prisms. Proposed to use a built-in force measuring transducer, which consists of an elastic sensitive element (ESE) and a capacitive sensor (CS) into PA structure. The purpose of this article is to create a force meter in the clamping prisms of the stator core of a powerful TG using an elastic sensitive element and a capacitive sensor built into the design of a "caseless" power battery to stabilize the pressing pressure of the stator core of a powerful turbogenerator. A number of TG and PA parameters, which should know to calculate the mechanical characteristics of the disc spring unit outlined. The dependence of the force of the spring block on the displacement of the pressure plate of the stator core is determined. Showing that the assessment of the force in the tightening prism performed by measuring the electrical capacity between the potential electrode CS and the grounded element of PA. Measuring the height of the block during planned repairs or operation of the turbogenerator allows you to determine with high accuracy the amount of tension on each tightening prism and therefore the compression force of the core and, if it necessary to adjust the pressing force by tightening the springs. The conversion function of the force converter is determined, taking into account the geometric dimensions of the ESE and CS. The calculation of ESE for mechanical strength was carried out. The use of pressure gauges in tightening prisms allows you to effectively restore and maintain the pressing force of the final packages of the stator core, control the pressure during operation and adjust it without stopping the turbogenerator. The obtained results can be used in systems for stabilizing the pressing force of the stator core with power accumulators and in the system for assessing the current state of the stator core of powerful turbogenerators of the TGV-200 and TGV-300 type. Increasing the accuracy of measurements and reducing operational risks will contribute to the rapid and effective restoration of critical infrastructure and ensure the stable operation of energy facilities.

Research on the anti-slip performance of arc groove cable clamps

Cable clamps are crucial for connecting component and transmitting prestress in cable structures. The anti-slip performance of the cable clamp is an important factor affecting the stability and safety of the structure. This paper introduces a novel test device to evaluate the anti-slip performance of arc groove cable clamps, and anti-slip performance experiments are performed on four arc groove cable clamps and four straight groove cable clamps. Long-term high strength bolt preload loss tests are conducted to investigate the loss pattern. Furthermore, seventeen parametric finite element models are developed to analyze the effects of groove bending angle, bolt length, cable force, and pressure plate stiffness on the anti-slip performance of arc groove cable clamps. It is found that the arc groove cable clamp exhibits a higher anti-slip bearing capacity, with a friction coefficient equivalent to that of the straight groove cable clamp, both exceeding 0.2. The bolt preload stabilizes at a certain value after 96 h of screwing the bolt, while it stabilizes after 24 h of tensioning the cable. The increase in the bolt length and angel of arc groove, as well as the reduction in the stiffness of the pressure plate, have a positive impact on the anti-slip bearing capacity of the arc groove cable clamp. There is a critical cable force that results in the lowest anti-slip bearing capacity of the arc groove cable clamp. These research results provide valuable insights for the design and engineering application of arc groove cable clamps.

Leafina: Potency of Kakawate leaves, fishbone meal and saba banana peel compost soil amendment to the water holding capacity of loam soil

In tropical regions like the Philippines, drought susceptibility is caused by high evaporation rates and poor soil water retention. To deal with this, soil amendments are crucial, enhancing soil properties to aid plant growth. In this study, LeaFiNa, a compost soil amendment composed of Kakawate leaves (KL), fishbone meal (FB), and Saba banana peels (BP) was introduced, aiming to boost soil water holding capacity (SWHC) of loam. Different LeaFiNa ratios were tested, including 3KL:1FB:2BP, 6KL:4FB:1BP, and 3KL:8FB:1BP, alongside vermicast and commercial soil amendment (neem cake) as positive controls, and plain loam soil as the negative control. Percolation method and pressure plate extraction was performed. One-way ANOVA showed a significant difference among the experimental treatments (α=0.05) in which 6KL:4FB:1BP ratio emerged with the highest SWHC of 49.60%. Meanwhile, Tukey’s HSD test revealed no significant difference between 6KL:4FB:1BP and vermicast, yet a significant difference with the negative control. Moreover, the experimental treatments, particulalry the 6KL:4FB:1BP, also exhibited ideal results on other SWHC parameters such as the soil moisture content at saturation and wilting points, and in terms of gravitational water and plant available water. These findings suggest the LeaFiNa’s potential in alleviating drought stress in tropical soils by enhancing water retention, offering promising outcomes for sustaining agricultural productivity in water-scarce regions.

Deep learning based fault detection of automobile dry clutch system using spectrogram plots

Dry friction clutches are extremely important in the context of power transmission systems. Continuous exposure to extreme heat and loading makes clutch extremely susceptible to various faults. The timely detection and diagnosis of such faults are of utmost importance to prevent any damage to internal components and also helps in avoiding transmission system failures. In this research study, a novel approach that leverages the power of transfer learning (a famous deep learning technique) is proposed to diagnose multiple types of clutch faults including, worn release fingers, fractured pressure plates, deteriorated pressure plates, loss of friction material and distorted tangential strips using spectrogram plots. To train and validate the diagnostic system, vibration readings were taken from a specially designed test rig with the help of piezoelectric accelerometer while the clutch system was operated under different load conditions of 0 (no load), 5 and 10 kg This procedure of data collection was then repeated to acquire the vibration data for all of the fault conditions by replacing the good with fault components individually. These vibration signals were further processed and transformed into spectrogram plots that serves as the input data for the deep learning models considered. Fine-tuning techniques were applied on pretrained networks to maximise the prediction accuracy of the models to effectively determine and diagnose faults in the clutch system. For this study 12 pre-trained networks were chosen namely, Xception, InceptionResNet, DenseNet, AlexNet, VGG16, GoogLeNet, VGG19, ResNet101, ResNet50, InceptionV3, MobileNetV2 and ShuffleNet. To optimize the performance of deep learning models, a systematic adjustment of hyperparameters such as the train-test split ratio, learning rate, optimizer and batch size for each network model was carried out. Through careful experimentation and analysis, significant improvements in fault classification accuracy were achieved thereby enhancing the reliability and effectiveness of the diagnostic system. From the results it was noted that 100% classification accuracy was displayed by AlexNet (for the no load condition and the 10 kg load condition) and GoogLeNet (for 5 kg load condition) with extremely low computation times.

Irrigation scheduling needs to consider both plant‐available water and soil aeration requirements

AbstractGlobal food production relying on irrigated agriculture accounts for >70% of the global freshwater withdrawal. A thorough understanding of soil–water characteristics (SWCs) and critical soil–water values in the soil and subsoil is important for effective management of irrigated water. A critical soil–water “window” for plants is generally taken as the plant‐available water window without considering diffusion‐dominated soil aeration as a co‐requisite. This study examined SWC curves in vadose soil profiles (up to 1.5‐m depth) in eight pasture soils. The soil moisture measurements were made over matric potentials ranging from −1 to −1500 kPa using tension table and pressure plate apparatus. The van Genuchten model was used to parameterize the measured SWC curve, while the Millington‐Quirk model was used to derive soil–gas diffusivity from measured soil physical properties. We defined critical soil–water windows considering the threshold values for both plant‐available water and soil–gas diffusivity to ensure water and aeration corequisites for plant growth. The results clearly distinguished depth‐dependent regimes of gravitational, plant‐available, and unavailable water in selected profiles and their responses to soil structural changes across the depth. In some of the observed soil profiles, only 30%–60% of the plant‐available water window was able to be utilized by plants because the remainder existed under soil conditions where soil aeration was inadequate for plant growth, emphasizing the importance of considering both the plant's water and aeration requirements during irrigation scheduling. Further, the infiltration profiles in two selected soils under simulated irrigation highlighted the importance of a priori knowledge of the soil structure in deeper soil layers for scheduling irrigation.

Optimization, Design, and Manufacturing of New Steel-FRP Automotive Fuel Cell Medium Pressure Plate Using Compression Molding

In this work, a new plastic-intensive medium-pressure plate (MPP), which is part of a fuel-cell system, has been developed together with a steel plate meeting all mechanical and chemical requirements. This newly developed MPP had to achieve the objective of saving weight and package space. The use of compression molding as a manufacturing technique facilitated the use of glass mat thermoplastics (GMT) which has higher E-modules and strength compared to most of the injection molded materials. A steel plate was placed as an insert to help achieve the stiffness requirements. For the development, the existing MPP was benchmarked for its structural capabilities and its underlying functional features. Four different FRP materials were investigated in terms of their chemical and mechanical properties. PP-GMT material, which has both high mechanical performance and resistance against chemicals in the fuel cell fluid, had been chosen. Using the properties of the chosen PP-GMT material, topology optimization was carried out based on the quasi-static load case and manufacturing constraints, which gave a load-conforming rib structure. The obtained rib structure was utilized to develop the final MPP with adherence to the functional requirements of MPP. The developed plastic-intensive MPP exhibits a 3-in-1 component feature with a 55% reduction in package space and an 8% weight reduction. The MPP was virtually analyzed for its mechanical strength and compared with the existing benchmark values. Finally, a press tool was conceptualized and manufactured to fabricate the new plastic-intensive MPP, which was tested in a rig and validated in the FE model.

DO RUGBY BOOTS WITH A BLADED STUD INCREASE CONTACT PRESSURES THROUGH THE FIFTH METATARSAL COMPARED WITH A ROUNDED STUD? A BIOMECHANICAL STUDY

Fifth metatarsal fractures in sport are known to be associated with acceleration and cross cutting movements when running. It is also established that playing surface has an impact on the ground reaction forces through the foot, increasing the strain through the fifth metatarsal. But what impact does boot design have on these forces? Current thought is that boots that utilise a blade stud design resist sideways slipping of the planted foot more than boots with a rounded stud. This study aims to compare ground reaction forces through the fifth metatarsal in 2 two different designs of rugby boot to assess what impact stud design might have. The forces across the foot were measured using Tekscan in-shoe pressure plates in 24 rugby players. Each player was asked to complete an agility course to measure acceleration, cutting and cross-cutting in the two different designs of rugby boot, reproducing true playing conditions. The boots used were the Canterbury Phoenix Club 8 Stud boot and the Canterbury Speed Club Blade boot. The trial was conducted on an 4G artificial pitch at the Cardiff Arms Park rugby ground. Ethical approval was obtained from Bath University and a research grant was provided by British Orthopaedic Foot and Ankle Society. The blade boot had significantly higher contact pressures than the stud boot on the fifth metatarsal in the combined movements (17.909 ± 10.442 N/cm2 Blade Vs 16.888 ± 9.992 N/cm2 Boot; P < .0125; n= 864 steps in each boot group). The blade boot also produced higher pressure during cross-cutting (32.331 ± 13.568 N/cm2 Vs 27.651 ± 15.194 N/cm2 p < 0.007). Pressures were also higher in both acceleration and cutting, although not significantly so. These results will guide clinicians advising athletes in shoe design, especially those predisposed to or rehabilitating from a fifth metatarsal fracture.

An integrated approach to the assessment of balance and functional mobility in individuals with history of severe traumatic brain injury

Individuals who experienced severe Traumatic Brain Injury (sTBI) are often characterized by relevant motor dysfunctions which are likely to negatively affect activities of daily living and quality of life and often persist for years. However, detailed objective information about their magnitude are scarce. The aim of this study was to quantitatively assess the extent of motor deficits in terms of postural control effectiveness under static and dynamic conditions and to investigate the existence of possible correlations between the results of clinical tests and instrumental measures. Postural sway and functional mobility (i.e., instrumented Timed Up and Go test, iTUG) were objectively measured in 18 individuals with sTBI and 18 healthy controls using a pressure plate and a wearable inertial sensor. Additionally, participants with history of sTBI completed the Rivermead Mobility Index (RMI). One-way ANOVA and Spearman's rank correlation analysis were employed to examine differences between the two groups and determine potential correlations between the instrumental tests and clinical scales.The results show that people with sTBI were characterized by larger sway area and longer iTUG walking sub-phase. Significant correlations were also detected between RMI scores and iTUG total duration, as well as the walking phase. Taken together, these findings suggest that, even years after the initial injury, individuals with sTBI appear characterized by impaired postural control and functional mobility, which appears correlated with the RMI score. The integration of instrumental measures with clinical scales in the routine assessment and treatment of individuals with sTBI would result in more comprehensive, objective, and sensitive evaluations, thus improving precision in treatment planning, enabling ongoing progress monitoring, and highlighting the presence of motor deficits even years after the initial injury. Such integration is of importance for enhancing the long-term quality of life for individuals with sTBI.

Assessment of Two SWCC models for predicting the curve fitting parameters of lateritic soil: bentonite mixtures

This study compares the capabilities of soil water characteristic curve (SWCC) models by Brooks-Corey (BC) and van Genuchten (vG) in estimating the curve fitting parameters for lateritic soil—bentonite mixtures. The SWCCs of soil treated with 0–10% bentonite and compacted with British standard light (BSL) energy at compaction states representing dry of optimum, optimum, and wet of optimum conditions were measured by sequential desorption using pressure plate extractor. The fitting parameters of the two equations were determined by a non-linear fitting program. The fitting capabilities of the models on the measured data were compared by statistical indices namely the root mean square error (RMSE), linearity (R2) and index of agreement (d). Results revealed that volumetric water content increased as bentonite content increased with specimens containing 10% bentonite recording the highest and therefore has greater capacity to retain water/contaminants, while the air entry value (AEV) for the various soil mixtures also increased with higher bentonite content. The study also found that the estimated volumetric water contents approximated the measured values at all suctions with a high degree of accuracy with RMSE values that ranged from 0.0035 to 0.0150 for vG model which are somewhat lower than the values for BC equation. Similarly, R2 for the vG equation (≥ 0.99) are, on average, slightly higher than those of the BC fits. However, the d values associated with the BC model which varied between 0.788 and 0.971 are higher than those of the vG (0.784–0.968). Overall, the study established that the vG model proved marginally superior in respect of goodness of fit.

PROTOTYPING OF A TWO WHEELER CLUTCH HUB USING REVERSE ENGINEERING TECHNOLOGY

A clutch hub is a critical component in a two wheeler manual transmission system, responsible for transferring rotational power from the engine to the transmission gears and providing a mechanism for disengaging the gears to allow for smooth gear changes. The clutch hub is placed between clutch basket and pressure plate. The clutch plates are mounted on it. It has teeth at center hole which rotate with main shaft. The prototyping of clutch hub using reverse engineering technique, making it essential to understand its design and functionality reverse engineering is employed to deconstruct an existing clutch hub, analyze its dimensions and materials, and create an accurate digital 3D model is created using computer aided design software, by scanning the part and prototyping of clutch hub is made by using 3D printing technology. Key Words: Clutch hub, Reverse engineering, 3D Model, Prototyping, 3D printing.

Performance of a Set of Soil Water Retention Models for Fitting Soil Water Retention Data Covering All Textural Classes

A clean environment is an essential component of sustainable development, which is based on a comprehensive understanding of the behavior of water, soil, and air. The soil water retention (SWR) curve is a crucial function that describes how soil retains water, playing a fundamental role in irrigation and drainage, soil conservation, as well as water and contaminant transport in the vadose zone. This study evaluates the accuracy, performance, and prediction capabilities of 15 SWR models. A total of 140 soil samples were collected from different sites, covering all textural classes. Standard suction tests, using both hanging column and ceramic pressure plate extractors, were conducted to compile the SWR databank. 15 SWR models were selected and fitted to the SWR data points. Soil texture, bulk density, and organic matter were used to determine their effect on the performance of the SWR models. The results indicate that the Tani and Russo models exhibit the lowest levels of accuracy and performance among the selected models. Based on the Akaike and Bayesian information criteria analysis, the van Genuchten model exhibits the lowest values among the selected models, with poor prediction capabilities in estimating the SWR curve. The significance test at the 0.05 level (95% confidence interval) shows that according to the calculated p-values for the Pearson correlation coefficient between RMSE and texture, the Brooks-Corey and van Genuchten models are poorly influenced by soil properties. The performance of the models is not significantly affected by the soil organic matter. Similarly, bulk density does not significantly affect model performance except for the Brooks–Corey, van Genuchten, Tani, and Russo models. Among the SWR models considered, the double exponential, Groenevelt and Grant, and Khlosi et al. models demonstrate superior accuracy and performance in predicting the SWR curve. This is supported by lower values for RMSE, Akaike, and Bayesian information criteria.