http://nopr.niscpr.res.in/handle/123456789/64832 2026-10-11T04:23:11Z 2026-10-11T04:23:11Z Güngör, Kadir Demirer, Ahmet http://nopr.niscpr.res.in/handle/123456789/64843 2024-11-08T06:46:52Z 2024-11-01T00:00:00Z

Title: Dry Friction and Wear of Graphite-Filled PTFE Composites using Taguchi Approach Authors: Güngör, Kadir; Demirer, Ahmet Abstract: Composite plain-bearing specimens with a porous structure were produced from spherical bronze powders (100–200 μm) using sintering technology. Pure Polytetrafluoroethylene (PTFE) and PTFE composites were then impregnated into the porous bronze structure and coated onto the surface. The PTFE mixtures were reinforced with graphite particles, with the graphite powder (average particle size: 200 μm) incorporated into the PTFE solution at varying ratios. This process was applied using the spray coating technique. Wear experiments were conducted based on a design created using the Taguchi method. The experimental parameters were optimized using the L27 Taguchi orthogonal array to achieve optimal friction coefficient and wear loss. The results showed that the experimental and verification test results were highly consistent. The material type/graphite content had the most significant impact on the friction coefficient and wear loss (71.6% and 30.88%, respectively). Sliding speed had the greatest effect (55.06%) on bearing temperature. Elemental analysis and chemical characterization of the composite plain bearing specimens were conducted using Energy Dispersive Spectroscopy (EDS). The wear surfaces were examined via Scanning Electron Microscope (SEM).The study concluded that the most significant factor affecting bearing wear is the material type. The 10% graphite additive, which reduces friction in the material, yielded optimal results in the study. An increase in sliding speed leads to a rise in bearing temperature, which in turn accelerates wear. Compared to industrially used bearings, the study found that more graphite lubricant was impregnated into the pores of bronze, and the optimal 10% additive provided a positive advantage in wear performance. Page(s): 1161-1171

2024-11-01T00:00:00Z Barve, Purushottam S Deshpande, Yogesh V Zanwar, D R Bhoyar, Sunil Pund, S S http://nopr.niscpr.res.in/handle/123456789/64842 2024-11-08T06:43:34Z 2024-11-01T00:00:00Z

Title: Development of an Innovative Assembly Fixture for Machining Synchronization of Multi Fuse Parts on Vertical Machining Center and Productivity Enhancement Authors: Barve, Purushottam S; Deshpande, Yogesh V; Zanwar, D R; Bhoyar, Sunil; Pund, S S Abstract: Manufacturing fuse bodies for defence applications demand precision and efficiency, posing challenges due to the complexity of machining operations. This study proposes a novel fixture design to address these challenges on vertical machining center. The study highlights the practical utility of tailored fixture designs in defence manufacturing, offering a replicable framework for productivity enhancement. Two fixture types were modelled using SolidWorks, with the Type-B fixture selected for its superior production capabilities. The study focuses on a specialized Type-B fixture design for fuse body machining, supported by rigorous analysis and testing, distinguishes it and underscores its potential impact on defence manufacturing processes. ANSYS software, stress, strain, and deformation analysis guided the design and simulation process. The novel Type-B fixture reduced entire manufacturing time to 5.41 minutes per part, 33.76% quicker than conventional methods, resulting in a 34.02% increase in production rate (77 parts/shift). This research concludes critical efficiency concerns in defence manufacturing, offering a practical solution to improve productivity while maintaining quality standards. This research highlights the fixture's potential towards significant improvements in productivity and operational efficiency. The detailed comparison of performance of existing manufacturing process with the process using Type-B fixture is presented in this study. Page(s): 1172-1183

2024-11-01T00:00:00Z Xu, Wenjing Singh, Vineeta Swarup, Shivam Kant, Kamal Dwivedi, Abhishek Mamoria, Pushpa Virmani, Amit Kumar, Alok Agrahari, Omkar Kaushik, Vandana Dixit http://nopr.niscpr.res.in/handle/123456789/64841 2024-11-08T06:40:24Z 2024-11-01T00:00:00Z

Title: Gradient One-to-One Optimizer and Deep Learning based Student Stress Level Prediction Model Authors: Xu, Wenjing; Singh, Vineeta; Swarup, Shivam; Kant, Kamal; Dwivedi, Abhishek; Mamoria, Pushpa; Virmani, Amit; Kumar, Alok; Agrahari, Omkar; Kaushik, Vandana Dixit Abstract: Student stress-based issues are considered as the most common reason in the student environment. Student stress level prediction is the major source for students’ academic performance and health. Students' stress levels increase the prevalence of psychological as well as physical challenges like nervousness, anxiety, and depression. Over the past years, different machine learning and deep learning based models have been proposed for student stress level prediction but they suffer certain limitations such as complex structure, less efficiency, high chance of misclassification, high chance of making mistakes. Predicting stress levels at early stage may help to minimize its impact and various serious health problems pertaining to this mental state. For this, automated frameworks are needed to predict stress levels accurately. This study proposes a hybrid approach named as GOOBO: DSNN (Gradient One-to-One Based Optimization: Deep Spiking Neural Network), that may identify stress accurately and efficiently utilizing optimization based hybrid of deep learning techniques. Here, the GOOBO is designed by incorporating Stochastic Gradient Descent (SGD) and One-to-One Based Optimization (OOBO). Here DSNN has been used which uses spiking neurons having different learning dynamics compared to traditional artificial neurons. Here proposed stress prediction model’s effectiveness has been enhanced by bio-inspired nature of DSNN simulating biological neural systems. The performance of the proposed GOOBO-DSNN is analyzed for its effectiveness using evaluation metrics such as accuracy, sensitivity, specificity, and precision. The proposed GOOBODSNN attained the maximum accuracy, sensitivity, specificity, and precision as compared to recently developed models. The proposed GOOBO-DSNN accomplished the higher accuracy, sensitivity, specificity, and precision of 90.976 %, 91.698 %, 91.336 %, and 90.179 % respectively. Duplicate attributes have been deleted, and missing values are filled in during the preprocessing step of the dataset. Page(s): 1184-1193

2024-11-01T00:00:00Z Prasad, Yashwant Saha, Subir Kumar Ravi, M R http://nopr.niscpr.res.in/handle/123456789/64840 2024-11-08T06:35:38Z 2024-11-01T00:00:00Z

Title: Design of Devices for Making Beads from the Stems of Holy Basil Authors: Prasad, Yashwant; Saha, Subir Kumar; Ravi, M R Abstract: This paper addresses the challenges faced by artisans in India who rely on traditional hand-operated lathes to craft beads from the stems of Holy Basil for making garlands, resulting in discomfort, physical strain, and fatigue. The research focuses on the design improvements of a wood-turning lathe specifically customized for this purpose. It details the design of two bead-making devices: one incorporating a timing belt and pulley system and another with an electronic drive mechanism. The design methodology employed the Systems Engineering Process along with Human-Centered Design approach. A participatory design process was followed, with the design team collaborating closely with bead-making artisans, local entrepreneurs, and manufacturing partners to develop the devices. The effectiveness and performance of the new devices were assessed by comparing them to traditional hand-operated lathes based on productivity, maintenance requirements, earnings, and affordability. Results indicated that artisan productivity and earnings doubled with the new devices. Affordability was demonstrated through the sale of over 90 units, with increased earnings justifying the investment. This integrated design approach facilitated the broader adoption of the new bead-making devices, thereby promoting livelihoods of artisans and the sustainability of the design intervention. Drawing on over three years of experience, this paper presents a framework for designing products for Base of the Pyramid sectors. The framework can be applied to develop similar cluster-specific technologies for resource-constrained communities in rural areas. Page(s): 1194-1205

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