Beam-Hopping and Resource Allocation for NOMA Based LEO Satellite Network: Genetic Algorithm

Shruti Sharma,Mesut Toka,Wonjae Shin 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.2

Non-destructive evaluation of steel and GFRP reinforced beams using AE and DIC techniques

Gaurav Sharma,Shruti Sharma,Sandeep K. Sharma 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.77 No.5

The paper presents an investigation of the widely varying mechanical performance and behaviour of steel and Glass Fibre Reinforced Polymer (GFRP) reinforced concrete beams using non-destructive techniques of Acoustic Emission (AE) and Digital Image Correlation (DIC) under four-point bending. Laboratory experiments are performed on both differently reinforced concrete beams with 0.33%, 0.52% and 1.11% of tension reinforcement against balanced section. The results show that the ultimate load-carrying capacity increases with an increase in tensile reinforcement in both cases. In addition to that, AE waveform parameters of amplitude and number of AE hits successfully correlates and picks up the divergent mechanism of cracking initiation and progression of failure in steel reinforced and GFRP reinforced concrete beams. AE activity is about 20- 30% more in GFRP-RC beams as compared to steel-RC beams. It was primarily due to the lower modulus of elasticity of GFRP bars leading to much larger ductility and deflections as compared to steel-RC beams. Furthermore, AE XY event plots and longitudinal strain profiles using DIC gives an online and real-time visual display of progressive AE activity and strains respectively to efficaciously depict the crack evolution and their advancement in steel-RC and GFRP-RC beams which show a close matching with the micro-and macro-cracks visually observed in the actual beams at various stages of loading.

Moment-Curvature behavior of steel and GFRP reinforced beam using AE and DIC Techniques

Gaurav Sharma,Shruti Sharma,Sandeep K. Sharma 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.84 No.2

Using non-destructive Acoustic Emission (AE) and optical Digital Image Correlation (DIC) methods, the momentcurvature behavior of steel and GFRP bars reinforced concrete beams under flexure was explored in this study. In the tension zone, laboratory studies were carried out on steel-RC and GFRP-RC beams with varying percentages of longitudinal reinforcement ratios of 0.33 %, 0.52%, and 1.11%. The distinct mechanism of cracking initiation and fracture progression of failure in steel-RC and GFRP-RC beams were effectively correlated and picked up using AE waveform characteristics of the number of AE hits and their amplitudes, AE energy as well as average frequency and duration. AE XY event plots and longitudinal strain profiles using DIC gives an online and real-time visual display of progressive AE activity and strains respectively to efficaciously depict the crack evolution and their advancement in steel-RC and GFRP-RC beams. They display a close matching with the micro and macro-cracks visually observed in the actual beams at various stages of loading.

Nutrient recycling of source-separated human faeces using biochar immobilized indigenous psychrotrophic bacteria for sustaining the agroecosystems of north-western Himalaya

Borker Shruti Sinai,Thakur Aman,Pandey Krishna Kanta,Sharma Pallavi,Manyapu Vivek,Khatri Abhishek,Kumar Rakshak 한국응용생명화학회 2024 Applied Biological Chemistry (Appl Biol Chem) Vol.67 No.-

The Himalayan composting toilets (CTs) offer a sustainable solution for converting human faeces (HF) into com post, supplementing the low-fertile land of the region. However, CTs face challenges such as delayed composting processes (6–8 months), increased heavy metal content, and foul odour. Therefore, the current study evaluated biochar-amended psychrotrophic bacteria for HF degradation under low-temperature conditions (10 ± 2 °C). Out of 153 psychrotrophic bacteria isolated from HF compost, 17 bacterial strains were selected based on highest and two or more hydrolytic activities. Furthermore, considering the isolation source, bacterial strains were exam ined for haemolytic activity, biofilm formation, cytotoxicity and seed germination assay. In total, 14 potential strains belonging to Pseudomonas, Microbacterium, Arthrobacter, Streptomyces, Glutamicibacter, Rhodococcus, Serratia, Exig uobacterium, and Jeotgalicoccus genera were considered safe for both human handling and plants. The composting process was conducted in modified plastic drums at 10 ± 2 °C for 90 days through two treatments: Treatment 1 (T1) involving HF, non-immobilized biochar and cocopeat, and Treatment 2 (T2) involving HF, consortium-immobilized biochar and cocopeat. The consortium-immobilized biochar (T2) degraded HF within 90 days with hemicellulose and cellulose degradation ratios of 73.9% and 62.4%, respectively (p ≤ 0.05). The compost maturation indices like C/N ratio (16.5 ± 1.85), total nitrogen (2.66 ± 0.07), total phosphate (0.4 ± 0.005), total potassium (1.8 ± 0.05) also improved in T2 treatment (p ≤ 0.05). Additionally, T2 was more effective in achieving safe levels of faecal coliforms (< 1000 MPN g−1) and reducing heavy metal content compared to T1. 16S rRNA amplicon-based analysis demonstrated an enhancement of bacterial community diversity in T2, with the presence of Rhodococcus, Pseudomonas, Arthro bacter, and Streptomyces at the end of the composting period promoting HF degradation. Furthermore, T2-fertilized soil showed a germination index (121 ± 0.4, p ≤ 0.05) and stimulated root, shoot and yield by 110%, 45.2%, and 288%, respectively, in pea (Pisum sativum var. AS-10) compared to T1 (49.6%, 19%, and 5.8%, respectively) (p ≤ 0.05). In con clusion, the developed biochar-based formulation proved effective in degrading HF at low temperatures, mitigating foul odours, reducing heavy metals, and enhancing the agronomic value of the final compost. This study presents a promising approach for the sustainable management of HF that can supplement the non-nutritive soil of high altitude regions.

Analysis of behavior of bare and in-filled RC frames subjected to quasi static loading

Balvir Sandhu,Shruti Sharma,Naveen Kwatra 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.73 No.4

Study on the inelastic response of bare and masonry infilled Reinforced Concrete (RC) frames repaired using Carbon Fibre Reinforced Polymers (CFRP) and Glass Fiber Reinforced Polymers (GFRP) subjected to quasi- static loading is presented in the work. The hysteresis behaviour, stiffness retention, energy dissipation and damage index are the parameters employed to analyze the efficacy of FRP strengthening of bare and brick in-filled RC frames. It is observed that there is a significant improvement in load carrying capacity of brick infilled frame over bare RC frame. Also FRP strengthened brick infilled frame performs much better than FRP repaired bare frame under quasi static loading. Repair and retrofitting of brick infilled RC frame shows an improved load carrying and damage tolerance capacity than control frame.

Aberrant DNA Double-strand Break Repair Threads in Breast Carcinoma: Orchestrating Genomic Insult Survival

Azad Kumar,Shruti Purohit,Nilesh Kumar Sharma 대한암예방학회 2016 Journal of cancer prevention Vol.21 No.4

Breast carcinoma is a heterogeneous disease that has exhibited rapid resistance to treatment in the last decade. Depending genotype and phenotype of breast cancer, there are discernible differences in DNA repair protein responses including DNA double strand break repair. It is a fact that different molecular sub-types of breast carcinoma activate these dedicated protein pathways in a distinct manner. The DNA double-strand damage repair machinery is manipulated by breast carcinoma to selectively repair the damage or insults inflicted by the genotoxic effects of chemotherapy or radiation therapy. The two DNA double-strand break repair pathways employed by breast carcinoma are homologous recombination and non-homologous end joining. In recent decades, therapeutic interventions targeting one or more factors involved in repairing DNA double-strand breaks inflicted by chemo/radiation therapy have been widely studied. Herein, this review paper summarizes the recent evidence and ongoing clinical trials citing potential therapeutic combinatorial interventions targeting DNA double-strand break repair pathways in breast carcinoma.

Non-contact damage monitoring technique for FRP laminates using guided waves

Mohit Garg,Shruti Sharma,등록되었습니다.,Rajeev Mehta 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.17 No.5

A non-contact, in-situ and non-invasive technique for health monitoring of submerged fiber reinforced polymers (FRP) laminates has been developed using ultrasonic guided waves. A pair of mobile transducers at specific angles of incidence to the submerged FRP specimen was used to excite Lamb wave modes. Lamb wave modes were used for comprehensive inspection of various types of manufacturing defects like air gaps and missing epoxy, introduced during manufacturing of FRP using Vacuum Assisted Resin Infusion Molding (VARIM). Further service induced damages like notches and surface defects were also studied and evaluated using guided waves. Quantitative evaluation of transmitted ultrasonic signal in defect ridden FRPs vis-à-vis healthy signal has been used to relate the extent of damage in FRPs. The developed technique has the potential to develop into a quick, real time health monitoring tool for judging the service worthiness of FRPs.

Monitoring degradation in concrete filled steel tubular sections using guided waves

Kumari Beena,Sharma Shruti,Sharma Sandeep,Kwatra Naveen 국제구조공학회 2017 Smart Structures and Systems, An International Jou Vol.19 No.4

Concrete filled steel tubes are extensively applied in engineering structures due to their resistance to high tensile and compressive load and convenience in construction. But one major flaw, their vulnerability to environmental attack, can severely reduce the strength and life of these structures. Degradation due to corrosion of steel confining the concrete is one of the major durability problems faced by civil engineers to maintain these structures. The problem accelerates as inner surface of steel tube is in contact with concrete which serves as electrolyte. If it remains unnoticed, it further accelerates and can be catastrophic. This paper discusses a non-destructive degradation monitoring technique for early detection corrosion in steel tubes in CFST members. Due to corrosion, damage in the form of debonding and pitting occurs in steel sections. Guided ultrasonic waves have been used as a feasible and attractive solution for the detection and monitoring of corrosion damages in CFST sections. Guided waves have been utilized to monitor the effect of notch and debond defects in concrete filled steel tubes simulating pitting and delamination of steel tubes from surrounding concrete caused by corrosion. Pulse transmission has been used to monitor the healthy and simulated damaged specimens. A methodology is developed and successfully applied for the monitoring of concrete filled steel tubular sections undergoing accelerated chloride corrosion. The ultrasonic signals efficiently narrate the state of steel tube undergoing corrosion.

Behaviour of bolted connections in concrete-filled steel tubular beam-column joints

Kumari Beena,Kwatra Naveen,Sharma Shruti 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.25 No.4

Many authors have established the usefulness of concrete filled steel tubular (CFST) sections as compression members while few have proved their utility as flexural members. To explore their prospective as part of CFST frame structures, two types of connections using extended end plate and seat angle are proposed for exterior joints of CFST beams and CFST columns. To investigate the performance and failure modes of the proposed bolted connections subjected to static loads, an experimental program has been executed involving ten specimens of exterior beam-to-column joints subjected to monotonically increasing load applied at the tip of beam, the performance is appraised in terms of load deformation behaviour of joints. The test parameters varied are the beam section type, type and diameter of bolts. To validate the experimental behaviour of the proposed connections in CFST beam-column joints, finite element analysis for the applied load has been performed using software ATENA-3D and the results of the proposed models are compared with experimental results. The experimental results obtained agree that the proposed CFST beam-column connections perform in a semi-rigid and partial strength mode as per specification of EC3.

Behavior of FRP strengthened RC brick in-filled frames subjected to cyclic loading

Balvir Singh,R. Siva Chidambaram,Shruti Sharma,Naveen Kwatra 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.5

Fiber reinforced polymer (FRP) sheets are the most efficient structural materials in terms of strength to weight ratio and its application in strengthening and retrofitting of a structure or structural elements are inevitable. The performance enhancement of structural elements without increasing the cross sectional area and flexible nature are the major advantages of FRP in retrofitting/strengthening work. This research article presents a detailed study on the inelastic response of conventional and retrofitted Reinforced Concrete (RC) frames using Carbon Fibre Reinforced Polymers (CFRP) and Glass Fiber Reinforced Polymers (GFRP) subjected to quasi-static loading. The hysteretic behaviour, stiffness degradation, energy dissipation and damage index are the parameters employed to analyse the efficacy of FRP strengthening of brick in-filled RC frames. Repair and retrofitting of brick infilled RC frame shows an improved load carrying and damage tolerance capacity than control frame.