bluuebunny/crossref_metadata_2025 huggingface dataset:
Harmony in Health: A Narrative Review Exploring the Interplay of Mind, Body, and Diabetes with a Special Emphasis on Emotional Stress
Authors: Balakrishnanpillai Jayakrishnan , Kesavadev Jothydev , Saboo Banshi
Published: June 2024

This comprehensive review explores the intricate connections between mind, body, and diabetes, with a particular focus on the profound impact of emotional stress on individuals managing this chronic condition. Drawing on a wealth of research spanning the intersection of psychology, physiology, and diabetes care, the review delves into the multifaceted ways, in which emotional stress can influence glycemic control, insulin sensitivity, and overall well-being. It extends beyond traditional biomedical perspectives to encompass psychosocial dimensions and emphasizes the reciprocal relationship between emotional well-being and diabetes outcomes. Insightful discussions are provided on the role of stress hormones, neurotransmitters, and inflammatory processes in mediating the complex interplay between mental health and metabolic regulation. Evidence-based strategies and interventions designed to empower individuals with diabetes in effectively navigating emotional stressors. This review aims to offer a holistic perspective on the intricate dynamics between the mind, body, and diabetes, shedding light on the significance of addressing emotional stress as an integral component of comprehensive diabetes care. The practical recommendations contribute to a deeper understanding of the nuanced relationship between emotional well-being and the intricate tapestry of diabetes management.
Coronavirus Disease 2019, a Popup Differential to the Postoperative Inflammatory State and its Impact on Outcomes after Cardiac Surgery – A Single-Center Experience
Authors: Ram Kiran K S , Trivedi Visharad , P. Venuthurupalli Rajesh S , Gehlot Deepika , Ninama Sunil
Published: June 2024

Introduction:

Coronavirus disease 2019 (COVID-19) affected care among surgical patients. Considering the underlying comorbidities, physical status, and intricate perioperative course, the cardiac surgery patient represents a vulnerable cohort. This study describes baseline characteristics, laboratory findings, diagnosis, postoperative course, and their correlation with immediate outcomes in patients undergoing cardiac surgery.

Methodology:

Patients who underwent cardiac surgery at our institute for 1 year were screened for COVID-19 with the reverse transcription-polymerase chain reaction swab test and then were posted for surgery only after corroborating negative reports, except for emergency cases. Dedicated preoperative areas and COVID-appropriate measures were taken. Data from the electronic patient records of those diagnosed with COVID-19 in the immediate postoperative period were reviewed retrospectively. Continuous normal distributed variables are presented as mean ± standard deviation, alternatively as median ± interquartile range, and categorical variables as percentages.

Results:

A total of 22 patients were infected in the immediate postoperative period in spite of appropriate screening and had a high mortality of 36.36% (vs. non-COVID 6.27%,P< 0.001). Days from index surgery to diagnosis were 6 (±3.75). The median stay in the intensive care unit and hospital stay was 6 (±2.75) and 10 (±3.2) days, respectively. The moderate and high-risk categories of the European System for Cardiac Operative Risk Evaluation II showed mortality of 33.3% (vs. 2.69% in non-COVID, odds ratio of 18.42) and 71.4% (vs. 11.2% in non-COVID, odds ratio of 19.65). Patients with C-reactive protein >100 mg/lit, D dimer >1000 ng/ml, and neutrophil/lymphocyte ratio >3.5 showed very high mortality. Noninvasive and invasive ventilation in 27.27% and 31.8%, respectively. Two patients acquired acute kidney injury that required hemodialysis.

Conclusions:

Despite requisite measures, COVID infection still remains a momentous differential to postoperative complications affecting early outcomes. Therefore, more robust preoperative protocols, better strategies for the COVID-free environment, and early clinical suspicion and workup are required to mitigate its effect on this cohort.
An Unusual Presentation of a Benign Giant Mature Intrathoracic Mediastinal Teratoma with Right Ventricular Failure and Cardiac Cachexia
Authors: Mohanty Satyapriya , Banerjee Anindya , Kumar Abhinav , Deb Pranjit , Singh Shashikant , Gupta Jaideep Das , Das Debasish
Published: June 2024

Mature mediastinal teratomas are infrequent, slow growing, and often asymptomatic. Traditionally, they present in the fourth decade or earlier and are found in the anterior mediastinum. These teratomas are often found incidentally on imaging, and surgical resection can be a challenge due to the size and location of the tumor; however, complete surgical excision is usually curative. Our case represents an infrequent benign giant (25 cm × 18 cm × 12 cm) mature intrathoracic mediastinal teratoma with uncommon clinical presentation of congestive heart failure and cardiac cachexia. The rare location of the tumor in the mid posterior mediastinum, very large teratoma, clinical presentation with right ventricular failure and cardiac cachexia, preoperative diagnostic dilemma, perioperative surgical challenge, and management marks this case unique.
Immature Mediastinal Teratoma Mimicking as Pulmonary Stenosis – A rare Presentation
Authors: Sarkar Shibsankar , Majumder Biswajit , Mohapatra Debasish , Ghosh Ratul
Published: June 2024

Anterior mediastinal teratoma can externally compress the pulmonary artery, which can present with symptoms of pulmonary stenosis rarely. We have reported a case of a 47-year-old male with immature mediastinal teratoma presenting as pulmonary stenosis. Initial physical examination revealed an ejection systolic murmur in the pulmonary area. With suspicion of valvular heart disease, the patient was referred to our cardiology department. Chest X-ray shows mass just above the left hilar zone. Two-dimensional echocardiography shows a mediastinal mass compressing the pulmonary trunk causing an obstruction. Contrast-enhanced computed tomography of thorax and magnetic resonance study confirmed the mediastinal mass. Fine-needle aspiration cytology of the mass suggestive of immature teratoma. The patient was transferred to the cardiothoracic vascular surgery department for further management. Mediastinal mass can mimic valvular heart disease with symptoms of cardiovascular pathology. Proper investigations for diagnostic clarity and prompt management are crucial in these conditions.
The behavior of mill tailings produced from a uranium extraction plant adapted an indigenously developed alkaline leaching-assisted process
Authors: Rana Barendra Kumar , Molla Samim , Dhumale M. R. , Jha S. K. , Kulkarni M. S.
Published: June 2024

The potential impact of tailings with respect to uranium and its associated toxic metals in the surrounding environment is assessed by identifying their concentrations and physicochemical behavior in the tailings. Tessier's sequential extraction method was used to study the speciation of U, Co, Zn, Mn, Fe, Pb, Cr, and Cd in different geochemical fractions of the alkaline mill tailings of the Tummalapalle process plant. The study indicated that uranium and other toxic metals present in the tailings have different chemical forms. Most of the toxic elements are not readily available in an exchangeable phase; rather, they are present in the tailings in stable complex form. However, a few elements, such as Co, Pb, and Cd, showed significantly higher concentrations in the oxidizing phase. The elements present in the oxidizing phases can be labile after prolonged exposure to atmospheric conditions. U (nat.) and Fe associated with the tailings are indicated to be mostly distributed in the residual phase. Radioactive disequilibrium of 238U and 232Th series radionuclides in the ore, waste rock, and tailings were studied. Disequilibrium was mostly noticed in the 238U series radionuclides in these matrices; however, the 232Th series radionuclides showed a radioactive equilibrium between their parents and daughters.
Theoretical evaluation of calibration factor for LR-115 cellulose nitrate solid state nuclear track detectors
Authors: Das Biswajit , Deb Argha
Published: June 2024

Alpha-sensitive solid-state nuclear track detectors (SSNTDs) are used successively for decades for determining the alpha-radiation level in various environmental materials. A model for measurement of total alpha-radioactivity in natural water by using alpha-sensitive LR-115 type II cellulose nitrate (CN) film SSNTDs has been developed in the present work. The LR-115 CN films in bare mode are assumed to be immersed into a water sample for alpha-exposure. During the exposure time period, the alpha-particles that are emitted from the alpha-emitters present in the water sample will interact with the CN film and create their latent trails in the film. These latent trails will be manifested as pits of alpha-tracks after chemical etching of the exposed film. For alpha-radioactivity measurement, calibration factor (CF) for LR-115 type II SSNTDs has been evaluated theoretically by using the range of alpha-particles of residual energies situated between 1.6 MeV and 4.7 MeV in natural water and the actual geometry of experimental setup for alpha-exposure. The evaluated CF is found to be 204.93 Bq.l − 1.(tracks. cm − 2.h − 1)−1. The evaluated CF and experimental procedure can reliably be utilized in monitoring the alpha-radioactivity of natural water and in other radioactivity field measurements.
Sustainable Microalgae-Membrane Photobioreactor System for Onboard Oxygen Production in an Aircraft
Authors: Subrahmanya Shreesha , Kumar Naveen , Ranjan Jayant , Kotnadh Shivaprasad
Published: June 2024

The purpose of the Air Generation System is to provide a constant supply of conditioned fresh air to meet the necessary oxygen availability and to prevent CO2 concentrations for the occupants in an aircraft. The engine bleed energy or electrical load energy consumed towards this circumstance accounts to be approximately 5% of total fuel burn and in turn, contributes to the global emissions of greenhouse gases.

This paper studies the improvement areas of the present conventional system such as fuel burn consumption associated with an aircraft ECS depending on the amount of bleed, ram air usage and electric power consumption. Improved systems for sustainability and hybridization in environmental control systems are desirable in aircraft.

This paper explains how a new design of the sustainable hybrid module assists the conventional system, by using a proposed modular MPBR. The MPBR system generates oxygen-enriched air, which is mixed with the traditional fresh air generated from conventional air generation systems.

MPBR system revitalizes the existing air and establishes more air recirculation when compared to a conventional system. It will reduce the demand for fresh air from the engine bleed in case of engine bleed aircraft or reduce the electrical load in case of more electric aircraft, which hereby improves engine efficiency.

The proposed system can also be used for redundant life support purposes during an emergency.

VOCs related to fuel consumption, maintenance, and global emissions of greenhouse gases can be addressed with the proposed solution. It applies to most of the aircraft variants and enhances sustainability, hybridization, reliability, and cost-effective features which would be of value and interest in a business case for the Suppliers, Manufacturers, and Customers side.
Consensus Based Air Transport System for Strategic Deconfliction for Urban Air Mobility
Authors: KG Sreenivasan , Suseelan SunilRaj , Huncha Pradeep
Published: June 2024

Urban Air Mobility (UAM) envisions heterogenous airborne entities like crewed and uncrewed passenger and cargo vehicles within, and between urban and rural environment. To achieve this, a paradigm shift to a cooperative operating environment similar to Extensible Traffic Management (xTM) is needed. This requires the blending of traditional Air Traffic Services (ATS) with the new generation UAM vehicles having their unique flight dynamics and handling characteristics. A hybrid environment needs to be established with enhanced shared situational awareness for all stakeholders, enabling equitable airspace access, minimizing risk, optimized airspace use, and providing flexible and adaptable airspace rules. This paper introduces a novel concept of distributed airspace management which would be apt for all kinds of operational scenarios perceived for UAM.

The proposal is centered around the efficiency and safety in air space management being achieved by self-discipline. It utilizes Blockchain’s core concepts like Distributed Ledger, Consensus, and Immutable Smart Contracts. The concept blends harmoniously to the Concept of Operations (CONOPS) recently published by Federal Aviation Administration (FAA), though the degrees of involvement by various actors of the eco system are primed for the very adaptation soon when fully autonomous aircraft are expected to dominate the urban skies. Strategic deconfliction and cooperative management are effectively realized with distribution of airspace knowledge, participative decision making and mutual trust. The concept is scalable to the foretold autonomy in this area. Trend predictors extrapolate a massive increase in dynamics, interactions and decision making as the flying vehicles count occupying a city's airspace, is set for exponential growth with personally owned flying vehicles. Proposed solution would operate efficiently with current computing technologies and can be scaled to be resident onboard or offboard the vehicle.
Assessing the Structural Feasibility and Recyclability of Flax/PLA Bio-Composites for Enhanced Sustainability
Authors: B S Dakshayini , Kancherla Kishore Babu , Raju Benjamin , Roy Mahapatra Debiprosad
Published: June 2024

Bio-composites have gained significant attention within the aerospace industry due to their potential as a sustainable solution that addresses the demand for lightweight materials with reduced environmental impact. These materials blend natural fibers sourced from renewable origins, such as plant-based fibers, with polymer matrices to fabricate composite materials that exhibit desirable mechanical properties and environmental friendliness. The aerospace sector's growing interest in bio-composites originates from those composites’ capacity to mitigate the industry's carbon footprint and decrease dependence on finite resources.

This study aims to investigate the suitability of utilizing plant-derived flax fabric/PLA (polylactic acid) matrix-based bio-composites in aerospace applications, as well as the recyclability potential of these composites in the circular manufacturing economy. The bio-composite laminate is produced through a compression molding process involving interleaved layers of PLA and flax fiber mats. We discuss the manufacturing technique, mechanical behavior, thermal characteristics properties of the bio-composite. A thorough comparison is drawn between these properties and those of similar bio-composites. Moreover, the study emphasizes the recycling of these bio-composites using mechanical milling, and their subsequent use as additives in the original fiber mat laminated composites. A comprehensive evaluation is conducted, contrasting the attributes of the original laminate with those of the laminate containing recycled additives.

The outcomes of this study will contribute to understanding and assessing the sustainability of bio-based polymer applications. By examining the performance of flax/PLA bio-composites in aerospace composite material qualification settings and investigating their recyclability, this research reveals the viability as an eco-friendly alternative in the aerospace industry, aligning with the industry's ongoing efforts to adopt greener practices and materials.
Buckling Knockdown Factor Estimation of Externally Pressurized Cylindrical Shells
Authors: Ramarathnam Santhosh , Jain Prakash Chand , Raju Gangadharan
Published: June 2024

Thin cylindrical shells under compressive loads typically experience failure through buckling. The buckling phenomenon in these structures often demonstrates a notable disparity between theoretical predictions and experimental outcomes. In the design of such structures, the theoretically determined critical load undergoes a reduction through a factor known as the Buckling Knockdown Factor (KDF). Traditionally, KDF has been empirically derived, and conservative lower bounds are established in industry standards. Recognizing the importance of minimizing structural mass, recent literature has presented promising results for estimating KDF using numerical methods in the context of cylinders under axial compression. This paper addresses the novel challenge of estimating KDF for cylinders subjected to external pressure using numerical techniques. A comprehensive survey of various methods for KDF estimation is conducted, and the Single Perturbation Load Analysis (SPLA) method, a deterministic lower-bound approach, is employed to determine the KDF. The investigation delves into the selection of imperfection shapes for SPLA under external pressure loading, considering two worst-case imperfection shapes: dimple and longitudinal dent. The findings suggest that SPLA can serve as an effective tool for estimating KDF under external pressure loading. Both the imperfection shapes yield similar KDF estimates, and the collapse behavior at the critical load is comparable. Importantly, the numerically estimated KDF is found to be less conservative than the industry standard KDF, indicating the potential for designing lighter structures.
Buckling and Post-Buckling Response of 3D Printed Cylindrical Shell with Circular Cutout under Axial Compression
Authors: Ravulapalli Vineeth , Raju Gangadharan , Manoharan Ramji , Naryanamurthy Vijayabaskar
Published: June 2024

Thin cylindrical shells are ubiquitous structural elements in aerospace structures, and they experience catastrophic buckling under axial compression. The recent advancements in theoretical and numerical studies aided in realising the role of localisation in shell buckling. However, the instantaneous buckling made it unfeasible for the experimental observations to corroborate the numerical results. This necessitates high-fidelity shell buckling experiments using full-filed measurement techniques. Cutouts are deliberate and inevitable geometrical imperfections in actual structures that could dictate the buckling response. Additive manufacturing makes fabricating shells with tailored imperfections and studying various conceivable designs feasible. Consequently, to comprehend the effect of circular cutout on the buckling response, cylindrical shells are 3D printed in thermoplastic polyurethane (TPU) with a circular cutout of a specific size that could significantly shorten the buckling resistance and tested under axial compression. The full-field response during the pre-buckling, buckling and post-buckling is captured using a Multi-Digital Image Correlation (mDIC) setup. The flexibility of TPU allows repeatability of the experiments, and the viscous characteristic of TPU slows down the pace of the buckling phenomenon, allowing the mDIC setup to capture the full-filed buckling and post-buckling even at a lower frame rate. The effect of loading imperfections on the final stable mode shape in the post-buckling regime is also captured. The acquired mode shapes and the strain fields can be used to develop accurate digital twin models to investigate the response of cylindrical shells with specific imperfection signatures and circular cutouts.
Design and Manufacturing of an Inclinometer Sensing Element for Launch Vehicle Applications
Authors: Shaju Tony M , Krishna Nirmal , Rao G Nagamalleswara , Kumar T Suresh , K Pradeep
Published: June 2024

Indian Space Research Organisation (ISRO) uses indigenously developed launch vehicles like PSLV, GSLV, LVM3 and SSLV for placing remote sensing and communication satellites along with spacecrafts for other important scientific applications into earth bound orbits. Navigation systems present in the launch vehicle play a pivotal role in achieving the intended orbits for these spacecrafts. During the assembly of these navigation packages on the launch vehicle, it is required to measure the initial tilt of the navigation sensors for any misalignment corrections, which is given as input to the navigation software. A high precision inclinometer is required to measure these tilts with a resolution of 1 arc-second. In this regard, an indigenous inclinometer is being designed. The sensing element of this design comprises of a compliant mechanism which is designed to sense the tilt by measuring the displacement of a proof mass occurring due to the respective component of earth’s gravitational acceleration force at a given inclination. This displacement is measured in terms of capacitance change, and is then used to calculate the tilt. The optimum design of this member is arrived upon by choosing the right material and by varying the section and geometry of the sensing element which influences the displacement of the proof mass. It is required to maximise the obtained displacement with high precision in order to achieve robust inclination measurements. A Design study is conducted to design an optimal geometry of the sensing element to meet the requirement of measuring the inclination with a resolution of 1 arc-second with a range of 1 degree. The results of the design study and the optimal input parameters selected for the final design are elaborated in this technical paper. The optimum design resulted in a proof mass displacement of more than 20 microns for a tilt of 1 degree (full range). Subsequently, the methods adopted for the precision manufacturing of the microfeatures on the sensing element are also discussed.
High Frequency Unsteady Pressure Measurement System for Aerodynamic Characterization
Authors: Varma Rekhanshi , SB Vidya , Jogi Deepak , MM Nandakishor , KC Finitha
Published: June 2024

Unsteady pressure fluctuations in launch vehicles can induce aerodynamic instabilities, potentially resulting in vibration, structural fatigue, and even catastrophic failure. These risks undermine structural integrity and jeopardize payload delivery, threatening mission success and crew safety. Therefore, precise measurements of unsteady pressure are vital for understanding dynamic pressure distribution and flow behaviour caused by phenomena like shock waves, vortices, boundary layer interactions, and flow separation. While ground-based wind tunnel tests have conventionally provided these insights, this paper presents an on-board system designed for real-time unsteady pressure data acquisition. The system addresses the challenge of accurately resolving high-frequency pressure variations over very high base pressure values. It can be integrated into re-entry vehicles and stage recovery experiments, providing confidence in acquiring data for complex geometrical shapes. Moreover, the capability to store and process data as per requirement during flight enhances its utility in practical scenarios. The system incorporates an 8-channel Sigma-Delta Analog to Digital Converter (Σ-Δ ADC) with necessary signal conditioning. A reprogrammable Field Programmable Gate Array (FPGA) handles data acquisition, ADC configuration and required processing for telemetry-based transfer and storage. Post-processing involves a Cascaded Integrator-Comb (CIC) compensation filter to enhance the overall frequency response within the intended bandwidth. This approach promises invaluable insights into launch vehicle dynamics and unsteady flow phenomena, with the system offering an accuracy of about 0.1% of full scale input range and supporting bandwidths up to 8 kHz.
Development of an Autonomous Blimp (Airship) for Indoor Navigation
Authors: S Syam Narayanan , Gangurde Yogesh , Marella Hitesh , Rannee Thivya , Rajalakshmi P
Published: June 2024

Unmanned Aerial Vehicles (UAVs) are useful for a multitude of applications in today’s age, covering a wide variety of fields such as defense, environmental science, meteorology, emergency responders, search and rescue operations, entertainment robotics, etc. One such category of UAVs is the lighter-than-air aircraft that provides advantages over the other types of UAVs. Blimps are among the participants of the lighter-than-air category that are expected to offer advantages such as higher endurance and range and safer and more comfortable human-machine interactions, as compared to fixed-wing and rotor-wing UAVs due to their design. This study details the development of a Robot Operating System (ROS)-based control system designed for the autonomous operation of the blimp. The paper explores the integration and implementation of ultrasonic sensors and Inertial Measurement Unit (IMU) technology to enhance collision avoidance capabilities during flight. Furthermore, the research includes an in-depth analysis of the blimp's stability under various operational conditions. The controller’s performance was found to be reliable, with a deficient cross-track error in different directions and altitudes. An integrated sensing module has been affixed to the experimental blimp, serving the purpose of capturing a comprehensive set of data, including video feed, temperature, humidity, and atmospheric pressure. This sophisticated sensing apparatus enhances the blimp's functionality, especially when deployed in external or outdoor environments. The video feed facilitates visual monitoring while collecting environmental parameters such as temperature, humidity, and pressure and provides valuable insights into the external conditions in which the blimp operates.
CFD Analysis of Cavitation in Flow through a Gerotor Pump and the Prediction of Erosion Zone due to Cavitation
Authors: Vasudevan Dinesh Babu , Turaga Vijay Kumar
Published: June 2024

A Gerotor pump is a positive displacement pump consisting of inner and outer rotors, with the axis of inner rotor offset from axis of outer rotor. Both rotors rotate about their respective axes. The volume between the rotors changes dynamically, due to which suction and compression occurs. Due to their high-speed rotations, a Gerotor pump may be subjected to erosion due to cavitation. This paper details about the Computational Fluid Dynamics (CFD) based methodology that has been used to capture cavitation bubbles, which might form during the operation of Gerotor pump and to identify the erosion zone which might be occur due to cavitation bubble getting burst near the surface layers of the gears. A full scale (3D) transient CFD model of a Gerotor pump has been developed using commercial CFD code ANSYS FLUENT. The most challenging part of this CFD flow modeling is to create a dynamic volume mesh that perfectly represents the dynamically changing rotor fluid volume of the Gerotor pump. Two different approaches have been used to model this dynamic mesh analysis in the Ansys Fluent tool – one method by using the traditional UDF script and, another method by using Python automation script. This CFD methodology includes complex geometry of the Gerotor along with moving fluid volume between two rotors. The complex flow through Gerotor has been successfully modeled using dynamic mesh & Volume of Fluid (VOF) model for entire 8 rotations. This paper helps an engineer to choose an easy and quick alternative method to model a complex flow through a Gerotor, understanding the flow physics and helps the engineers to improve the design by reducing erosion & increasing its life cycle.
Analysis for Effect of Angle of Attack on Coefficient of Lift of Wing Structure
Authors: Hujare Pravin P , Hujare Deepak P , Choudhary Prateek , Sakat Abhishek , Karanjkar Rushil
Published: June 2024

Dimensional optimization has always been a time-consuming process, especially for aerodynamic bodies, requiring much tuning of dimensions and testing for each sample. Aerodynamic auxiliaries, especially wings, are design dependent on the primary model attached, as they influence the amount of lift or reduction in drag which is beneficial to the model. This study aims to reduce the time period taken to finalize the design parameter for the same. For a wing, the angle of attack is essential in creating proper splits to incoming winds, even under high velocities with larger distances from the separation point. In the case of a group of wings, each wing is then mentioned as a wing element, and each wing is strategically positioned behind the previous wing in terms of its vertical height and its self-angle of attack to create maximum lift. At the same time, its drag remains variable to its shape ultimately maximizing the CL/CD ratio. A high value of CL indicates a significant component of horizontal drag is converted into a vertical lift. While the value of CD remains variable to different design factors, adjusting the angle of attack can minimize the drag forces caused by reducing the frontal area of impact. In this study two winged elements were considered for the front wing. Three parameters with 5 levels each were used for the parametric optimization. Twenty-five sets of setup designs were considered as a part of the Taguchi optimization study. The CL/CD ratio of X5 model obtained by CFD analysis is 15.78 and by experimental testing is 15.32. It is found that the CL /CD ratio obtained by Numerical analysis and Experimental investigation are well corroborated.
Development of Deployment Mechanism for RAMBHA-LP Payload Onboard Chandrayaan-3 Lander
Authors: Alam Mohammed Sabir , Paul Johns , Upadhyay Nirbhay Kumar , Nalluveettil Santhosh J , Sateesh Gollangi , A Jothiramalingam
Published: June 2024

RAMBHA-LP (Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere—Langmuir Probe) was one of the key scientific payloads onboard the Indian Space Research Organization’s (ISRO) Chandrayaan-3 mission. Its objectives were to estimate the lunar plasma density and its variations near the lunar surface. The probe was initially kept in a stowed condition attached to the lander. A mechanism was designed and realized for deploying the probe at a distance of 1 meter to avoid the plasma sheath effect in the moon’s plasma environment. The RAMBHA-LP deployment system consists of a metallic spherical probe with Titanium Nitride coating on its surface, a long carbon-fiber-reinforced polymer boom, a spring-assisted deployment mechanism, a dust-protection subsystem, and a hold release mechanism (HRM) based on a shape-memory alloy-based actuator. The entire RAMBHA-LP system weighed nearly 1.3 kilograms. The system had undergone many sub-system and system-level tests in ambient, dynamic, and thermo-vacuum environments, simulating interplanetary mission conditions. After completion of all developmental, qualification, and acceptance level tests, the system was integrated with the ‘Vikram’ Lander and launched using ISRO’s Launch Vehicle Mark III (LVM 3) on July 14, 2023. The Chandrayaan-3 lander made history by landing on the lunar south pole on August 23rd, 2023. The RAMBHA-LP payload was successfully deployed the next day. The deployment of the payload was confirmed by two status confirmation switches in the mechanism. This paper describes the design and configuration of the payload deployment mechanical system, with a focus on the design of the various mechanical subsystems, the results of software simulation and analysis, and the details of the large number of tests conducted to make the deployment system ready for the mission.
Design of Mini-Hexapod Rover System for Future Lunar Exploration
Authors: Shanbhag Sushanth Suresh , Sharma Shachindra , Damurothu Krishna , Sandeep R
Published: June 2024

Lunar tubes, natural underground structures on the Moon formed by ancient volcanic activity, offer natural protection from extreme temperatures, radiation, and micro-meteorite impacts, making them prime candidates for future lunar bases. However, the exploration of lunar tubes requires a high degree of mobility. Given the Moon's gravity, which is approximately six times weaker than Earth's, efficient navigation across rugged terrains within these lava tubes is achievable through jumping. In this work, we present the design of subsystems for a miniature hexapod rover weighing 1 kg, which can walk, jump, and stow. The walking system consists of two subsystems: one for in-plane walking, employing four single-degree-of-freedom (DoF) legs utilizing the KLANN walking mechanism, and another for directional adjustments before jumping. The latter employs a novel three-DoF mechanism with the cable-pulley system to optimize space utilisation. The design of these legs prioritizes functionality, minimizing the number of actuators and mass. Furthermore, we introduce a jumping mechanism featuring a spring-based energy storage system and a sector-gear-based release mechanism. This mechanism is engineered to enable jumps with a maximum horizontal range of 1 meter on the Moon. It has been 3D printed and independently demonstrated. Our work encompasses a comprehensive system-level design study, with a focus on sub-system-level functions for various mechanisms. The innovative mechanisms designed and demonstrated in this work hold potential for broader aerospace applications, including payload separation systems, pushing mechanisms, and door opening and closing mechanisms, among others.
Automatic Maneuver Detection in Flight Data Using Wavelet Transform and Deep Learning Algorithms
Authors: Parihar Pratik , Kumar Utsav , Kaliyari Dushyant , Tk Khadeeja Nusrath
Published: June 2024

Aircraft performance, certification and safety hinge on the precise analysis of flight maneuvers, necessitating a methodical approach to extract critical insights from flight data. This research outlines a systematic methodology that combines signal processing with machine learning techniques for the detection and analysis of aircraft maneuvers. The core of this methodology involves the Wavelet Transform, which meticulously unveils temporal intricacies within flight data, shedding light on pivotal time-frequency attributes crucial for aviation safety assessments. Augmenting this approach, Long Short-Term Memory (LSTM) models are employed to capture intricate temporal dependencies, extending the capability beyond that of standalone machine learning. This methodology not only enhances aviation safety but also finds wide-ranging applications. By examining flight attitudes during actions and extracting multi-parameter time histories, it establishes standardized time histories for each maneuver type, which are performed for system identification, air-data calibration, and performance analysis. This standardized technique significantly reduces the time needed for data pre-processing, enabling analysts to focus on in-depth analysis. The interdisciplinary collaboration underlying this research highlights the immense potential of combining signal processing and machine learning to shape the future of aviation research and applications, for example. It provides a versatile framework to analyze flight data and glean insights into pilot maneuvering, which can be instrumental in enhancing aviation safety, pilot training, and decision-making processes. This approach transcends the limits of conventional maneuver detection and analysis, laying the foundation for more precise and efficient flight operations. Its implications extend to various sectors of aviation research, emphasizing the pivotal role of integrated methodologies in shaping the trajectory of aviation safety and performance.
Synergized Mixed-Signal System-on-Chip (SoC) Design and Development Using System-Level Modeling and Simulation
Authors: Savithri G , Saritha T , Bhargavi M Bindu , Teza BS , Poreddy Sushma , Kumar M Madhava , Durga G Vijaya , Verma Usha P , Siddani Kishore , Viswanathan Vidya
Published: June 2024

In recent decades, innovative System-on-Chip (SoC) design has become a critical area of research, driven by emerging trends and complex application demands. SoCs, which integrate analog, digital, and mixed-signal components, along with software, present significant design and verification challenges. Modeling and Simulation constitutes a powerful method for designing and evaluating these complex systems, enabling system designers in concept realization, experimentation, optimization, and validation. This paper introduces a ‘Synergized SoC design flow with Modeling and Simulation’ applied in the design and development of SoC for a radar target emulator application. This synergized flow uniquely integrates system-level modeling and simulation with the traditional SoC design and development process to effectively address design and verification needs. Our approach not only accelerates the SoC design cycle time but also provides a comprehensive framework for future innovations in the SoC development.
Hybrid Cooling System for Thermal Management in Electric Aerial Vehicles
Authors: Nyamagoudar Vinayak , P R Namratha , Balasubrahmanyam Madireddy , Vanka Sridhar , Gattu Raghavendra , Abuheiba Ahmed , Jha Rajesh Kumar
Published: June 2024

Continuous improvements and innovations towards sustainability in the aviation industry has brought interest in electrified aviation. Electric aircrafts have short missions in which the temporal variability of thermal loads is high. Lithium-ion (Li-ion) batteries have emerged as prominent power source candidate for electric aircrafts and Urban Air Mobility (UAM). UAMs and Electric aircrafts have large battery packs with battery capacity ranging in hundreds or thousands of kWh. If the battery is exposed to temperatures outside the optimum range, the life and the performance of the battery reduces drastically. Hence, it is crucial to have a Thermal Management System (TMS) which would reduce the heat load on battery in addition to the cabin thermal loads.

Thermal management can be done through active or passive cooling. Adding a passive cooling system like Phase Change Material (PCM) to the TMS reduces the design maximum thermal loads. However, the added weight of the PCM module may at times outweigh the benefit of energy savings. This research studies thermal management of electric aircrafts/UAMs using Vapor Cycle System (VCS), Phase Change Material (PCM) and combination thereof (Hybrid). The three TMS architectures are compared for different UAM/electric air vehicle, and the results will help us conclude the best method of cooling. The analysis of the results quantifies the impact of the architecture on the weight and size metrics on the UAM/electric air vehicles. Also, three representative UAM/electric air vehicles of different capacities are simulated using MATLAB, and their results will help us to optimize the best TMS that can be applied to electric aerial vehicles of varying passenger capacity depending on its heat loads. The simulated results show for lower heat loads PCM alone, and for higher heat loads hybrid TMS provide best cooling solution.
Formal Technique for Fault Detection and Identification of Control Intensive Application of Stall Warning System Using System Theoretic Process Analysis
Authors: Kale Alexander , Madhuranath Ganesh , Shanmugham Viswanathan , Nanda Manju , Singh Giresh , Durak Umut
Published: June 2024

Faults if not detected and processed will create catastrophe in closed loop system for safety critical applications in automotive, space, medical, nuclear, and aerospace domains. In aerospace applications such as stall warning and protection/prevention system (SWPS), algorithms detect stall condition and provide protection by deploying the elevator stick pusher. Failure to detect and prevent stall leads to loss of lives and aircraft.

Traditional Functional Hazard and Fault Tree analyses are inadequate to capture all failures due to the complex hardware-software interactions for stall warning and protection system. Hence, an improved methodology for failure detection and identification is proposed. This paper discusses a hybrid formal method and model-based technique using System Theoretic Process Analysis (STPA) to identify and diagnose faults and provide monitors to process the identified faults to ensure robust design of the indigenous stall warning and protection system (SWPS). The technique is implemented for the SWPS system to ensure the detection of faults due to electric, sensor and computational integrity. Once a fault is detected, a graceful degradation of system functionality is ensured, and appropriate caution/warning annunciations are provided to alert the crew. This has been analyzed and demonstrated on the simulated platform.

Proposed Methodology uses the Concept of Operations and STPA to derive the control logic model for monitors for fault detection and identification. These monitors analyze data from angle of attack sensors, Air data computational units and Attitude heading reference system for developing a robust logic for SWPS to minimize both false positives and false negatives.

The efficacy of the proposed hybrid technique has been demonstrated on the real time flight simulator with aircraft flight data
Inverse Approach for Metasurface Based Radar Absorbing Structure Design for Aerospace Applications Using Machine Learning Techniques
Authors: P K Anjana , V Abhilash P , Bisariya Siddharth , Sutrakar Vijay Kumar
Published: June 2024

Metasurfaces comprised of sub-wavelength structures, possess remarkable electromagnetic (EM) wave manipulation capabilities. Their application as radar absorbers has gained widespread recognition, particularly in modern stealth technology, where their main role is to minimize the radar cross-section (RCS) of military assets. Conventional radar absorber design is tedious because of its time-consuming, computationally intensive, iterative nature, and demand for a high level of expertise. In contrast, the emergence of machine/deep learning-based metasurface design for RCS reduction represents a rapidly evolving field. This approach offers automated and computationally efficient means to generate radar absorber designs. In this article, an inverse approach, using machine/deep learning methodology is presented for multilayered broadband microwave absorber. The proposed method is primarily based on geometry and absorption characteristics. The proposed design is based on an in-depth understanding of the behavior of an optimized, practically implementable impedance sheet-based meta-atom, and its electromagnetic variations relative to its overall dimensions and thickness. The meta-atom selected for this modelling is a Jerusalem cross and the data set used for the model consists of the geometry, thickness, and corresponding absorptivity. The predicted results of machine and deep learning models are further validated by simulating EM performance using full wave simulation software. The results predicted by the models are in good agreement with EM simulations from the C to K bands of frequencies. This model can be employed to create radar-absorbing structures using a single meta-atom design, tailored to various frequency bands.
Aerospace Vehicle Motion Simulation with Real-Time Telemetry Data
Authors: Shaw Sandeep Prasad , Thakur Adarsh , Nair Thara , KK Raveendra
Published: June 2024

With regards to any aerospace mission, it is very useful to have awareness about the state of vehicle, i.e., the information about its position, velocity, attitude, rotational rates and other concerned data such as control surface deflections, landing gear touchdown, working of mechanisms and so on. The sensor data from the vehicle that is communicated to the ground can be difficult to perceive and analyze. A frame work for real-time motion simulation of an aerospace vehicle from onboard telemetry data is henceforth developed in order to improve the understanding about the current state of the mission and aid in real-time decision making if required. The telemetry data, that is transmitted through User Datagram Protocol (UDP), is received and decoded to usable format. The visualization software accepts the data in a fixed time interval and applies the required transformations in order to ensure one-to-one correspondence between actual vehicle and simulation. The transformations required for missions with various scope are formulated. Data handling scheme for low frequency data and data loss are also discussed. The importance of environment design emphasized, the 3D terrain is created from satellite imagery and heightmap or digital elevation model. The shader for volumetric atmosphere useful for surface to space missions, is created using an algorithm that simulated scattering of light in the atmosphere. For larger environments required for launch vehicle missions, a scaling scheme is worked out and is implemented in combination with the floating-origin algorithm to deal with the floating-point limitations posed by current generation graphic engines. Techniques such as quad-tree structures for level of detail (LOD) rendering are used for optimization of performance. Animation of flight events are rigged and get triggered based on flags in telemetry data. The developed framework was tested in critical demonstration missions for ISRO – The Reusable Launch Vehicle Landing Experiment (RLV-LEX) and Test Vehicle Demonstration Mission -1 (TV-D1). The framework can be used for a variety of missions such as launch vehicles, spacecrafts, UAVs and even landers & rovers.
Аналіз напружено-деформованого стану втулок несучого шару від дії статичного навантаження
Authors: Деньщиков Олександр Юрійович , Гребенюк Ярослав Володимирович , Савін Олександр Борисович , Мірошніков Віталій Юрійович
Published: June 2024

Запропоновано метод розв’язання просторової задачі теорії пружності для шару на врізаних циліндричних опорах з втулками. Втулки розглядаються як товстостінні труби. На плоских поверхнях шару задані напруження, на внутрішніх поверхнях труб задані переміщення. Між шаром та трубами задані умови спряження у вигляді жорсткого з’єднання. Матеріали шару та труб пружні, однорідні з різними фізико-механічними властивостями. Шар та труби розглядаються в різних локальних системах координат (декартовій та циліндричних). Для розв’язання задачі застосовується рівняння Ламе. Поєднання базисних розв’язків рівняння Ламе в різних системах координат відбувається за допомогою аналітико-числового узагальненого методу Фур’є. Задовольняючи граничним умовам та умовам спряження створена система лінійних алгебраїчних рівнянь другого роду, до яких застосований метод редукції. Чисельний аналіз показав високу збіжність результатів до точного (точність виконання граничних умов склала 10-5 при порядку системи рівнянь m = 4 для значень від 0 до 1). Аналіз напруженого стану проведений для пластикової втулки різної товщини та шару з алюмінієвого сплаву Д16Т. Отримані результати свідчать, що при зменшенні внутрішнього радіусу втулки напруження на її поверхні значно зростають, що повинно бути враховано при застосуванні матеріалів з низькими фізико-механічними характеристиками. Запропонований метод може бути застосований для отримання високоточних результатів під час проєктування з’єднань деталей машин і механізмів, модель яких є шар на циліндричних врізаних опорах з втулками. Отримані числові результати можуть бути застосовані для прогнозування геометричних параметрів під час проєктування.