Nikhil Kumar Thakur - Academia.edu (original) (raw)

Papers by Nikhil Kumar Thakur

Engineering materials, 2021

Ferrite nanoparticles have a significant impact in determining the dielectric behaviour and are p... more Ferrite nanoparticles have a significant impact in determining the dielectric behaviour and are promising materials for microwave and high frequency antenna applications. Thus chapter presents the frequency as well as temperature reliant dielectric properties of Mn 2+ doped Mg 0.5 Zn 0.5−x Mn x Fe 2 O 4 (where, x = 0.125, 0.250, 0.375, 0.500) nano-ferrites synthesized by co-precipitation. In comparison to that at higher frequencies, the dielectric constant falls dramatically at low frequencies. For every sample, the loss tangent was found to be minimal. The temperature reliant dielectric analysis of prepared samples reveals that the dielectric relaxation occurs at higher temperatures of approximately 531-667 K. The nano-ferrites being studied have minimal loss tangent values, making them potential candidates for microwave device applications.

Zenodo (CERN European Organization for Nuclear Research), Mar 30, 2022

Throughout the globe, abiotic stress is a serious threat to agriculture. Moreover, the extreme cl... more Throughout the globe, abiotic stress is a serious threat to agriculture. Moreover, the extreme climatic conditions like drought, flooding, global warming and others are the major yieldlimiting factors for crop plants and impacts forceful challenges to global crop production. Contribution of Brassica Napus is more towards the oilseed industry and has also achieved worldwide acceptance. It is the third most important source for vegetable oil for human consumption after palm and soybean oils. Canola crop is widely used as vegetable oil and meals for animals and is one of the first genetically modified crops to reach commercial markets of Canada. Genetic modification is required to protect these kinds of crops from various kinds of stress such as metal stress, extreme climatic conditions, drought and saltiness. In this review, we have discussed the current and future role of genetic engineered canola to sustainable agriculture systems.

Journal of Alloys and Compounds, Sep 1, 2023

Journal of energy storage, Jun 1, 2022

Physica Scripta, May 4, 2023

Lead-free Perovskite materials have acquired a lot of interest owing to their potential to overco... more Lead-free Perovskite materials have acquired a lot of interest owing to their potential to overcome the stability and toxicity concerns compared to traditional perovskite solar cells. Chalcogenide perovskites (ABX3, where A = Ba, B = Zr, X = S and/or Se) are emerging materials for photovoltaic (PV) applications. Computer-based designing of metal chalcogenide semiconductors, resulting in the identification of extremely appealing ABX3 substances and their derivatives that may be used as absorbers in thin-film PV devices. In this context, here the numerical studies are performed using the SCAPS-1D simulator for designing of chalcogenide perovskites-based solar cells. We used FTO (Fluorine-doped tin oxide), TiO2 as electron transport layer (ETL), BaZrS3, and BaZrSe3 as an absorber layer, Spiro-OMeTAD as a hole transport layer (HTL), and Au as a metal back contact. The simulations are conducted under AM 1.5G solar spectrum designed to maximise the efficiency of the proposed solar cell. The selection of the optimal parameters such as thickness, defect density and temperature for all the layers including absorber, FTO, ETM, and HTM is examined. The parameters are considered, keeping in mind their impact on solar cell performance, budget effectiveness, and the physics of the entire solar cell architecture. The effect of temperatures between 300 K to 450 K is studied. The results indicate that the power conversion efficiency (PCE), FF (fill factor), Voc (Open Circuit Voltage) and Jsc for BaZrS3 is 12.12%, 79.40%, 0.70 V, 22.00 mA cm−2, respectively, whereas for BaZrSe3 it is 25.84%, 77.32%, 0.72 V, 46.65 mA cm−2, respectively. This shows that BaZrSe3 has the potential to replace BaZrS3.

Materials Today: Proceedings

International Journal of Research Publication and Reviews

The present work aims at improve the Frequency of NSD (Nash Shell Damper) muffler by controlling ... more The present work aims at improve the Frequency of NSD (Nash Shell Damper) muffler by controlling the noise level of a diesel engine by developing an exhaust muffler for the same, since exhaust noise is the single largest contributor to the overall noise from the engine.

Cost estimation is an important activity for advanced understanding of product/process knowledge ... more Cost estimation is an important activity for advanced understanding of product/process knowledge that is used to plan activities accordingly. For composite material parts, choices of materials and their methods of manufacturing are broad and thus complexity is high. Design is complex too involving tight tolerances leading to need of a new and advanced costing system. Proper knowledge management followed by improving the current cost estimation methods is a viable solution. This paper proposes a logical knowledge-based advanced cost estimation methodology that uses a mathematical set theory-based knowledge management system designed by utilising a generic product life-cycle for Knowledge Information & Data collection. This acquired KID is represented as parent sets, subsets and elements. The knowledge structure so created is coupled to a mixed method of cost estimation for developing logical advanced cost estimation system that can be used for both composite and conventional costing....

The focus of this research is divided into two different independent fields. First is to recogniz... more The focus of this research is divided into two different independent fields. First is to recognize hand gestures captured from a webcam in real-time, and then using the gestures to control real-world applications (in our case, apply its output to control Operating System operations). Gestures can be used to communicate much more information by itself compared to mice, keyboard etc. This comes under static hand recognition system. Second is to dynamically track the hand movements and control the mouse using these movements. Further functionalities in static as well as dynamic implementation can be increased to make the project much more effective.

Cost estimation is a technique wherein the cost related to a product or a project is predicted we... more Cost estimation is a technique wherein the cost related to a product or a project is predicted well in advance to make planning easy and simple. For composite components, stakeholders’ requirements and technical requirements are complex. Large number of cost drivers with very little knowledge of composite technology makes cost estimation a difficult task. Uncertainty in information is another problem in cost estimation. Proper KM and automation are necessary for making cost estimation models simple and flexible. KBE is a cyclic process where knowledge is captured, assimilated, refined, coded, automated and reused in a desired format to save time. This paper presents a review of the current knowledge about composite materials, their cost estimation techniques and use of KBE in cost modeling. This paper also shows the drawbacks of the current system which can be overcome by applying the benefits of KBE.

Cost estimation for a composite material part requires cost driver information from various activ... more Cost estimation for a composite material part requires cost driver information from various activities just like any other material part. Every process involved to convert the product from raw material to finished state requires the consumption of certain cost value. The activities that are responsible for these cost changes are termed as cost drivers. Process cycle or life-cycle is a way to represent the processes necessary in a products complete journey. It is important to map different phases in a processes and include them in the life-cycle for proper analysis and management. The present work reviews the importance of different phases in a processes and quantifies the contribution of various processes in the composite material part overall cost. This contribution is represented in a tabular form and then compared to conventional method of life-cycle. The importance of including carbon footprint in the life-cycle is also reviewed and finally a generic process/ project life-cycle ...

Composites have been used all over the world when it comes to developing advanced light weight an... more Composites have been used all over the world when it comes to developing advanced light weight and highly efficient components. Companies like Boeing and Airbus have successfully used more than 50% composites by weight in their aircraft’s structural and non-structural parts, which has been found to increase efficiency, cut down weight by 30% and absorbed vibrations. This triggered a need to develop new and advanced engines that are both light in weight and efficient and can support these aircrafts. Hence, to cope with this new engineering requirement, companies like Rolls-Royce and General Electric are developing advanced engines using composite materials. The use of composites in aero-engines has brought forth certain challenges. One of the main challenge is to predict cost of the composite part very early in the decision making phase so as to improve design efficiency. The current methods/techniques of Cost Estimation (CE) have been designed taking a product or a manufacturing pro...

Background: The postoperative wound hematoma after anterior cervical spinal surgery is a very cri... more Background: The postoperative wound hematoma after anterior cervical spinal surgery is a very critical complication. We aim to explore the risk factors independently associated with postoperative wound hematoma in patients who have undergone anterior cervical spine surgery. Methods: Clinical data of patients with cervical spondylosis or cervical disc herniation who underwent anterior cervical spine surgery by the senior author from January 2011 to December 2017 were evaluated. A multivariate logistic regression was conducted to compare the hematoma group and the non-hematoma group in order to find out which factors that were independently associated with hematoma formation. Mann-Whitney U test was conducted to compare the Neck disability Index score in two groups. Results: A total of 678 patients met the criteria who underwent anterior cervical spine surgery. 13 patients were identified as wound hematoma who have undergone hematoma evacuation, in which hemorrhage sites were found. M...

World Neurosurgery: X, 2019

BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-... more BACKGROUND: Neurosurgical task shifting and task sharing (TS/S), delegating clinical care to non-neurosurgeons, is ongoing in many hospital systems in which neurosurgeons are scarce. Although TS/S can increase access to treatment, it remains highly controversial. This survey investigated perceptions of neurosurgical TS/S to elucidate whether it is a permissible temporary solution to the global workforce deficit.-METHODS: The survey was distributed to a convenience sample of individuals providing neurosurgical care. A digital survey link was distributed through electronic mailing lists of continental neurosurgical societies and various collectives, conference announcements, and social media platforms (July 2018eJanuary 2019). Data were analyzed by descriptive statistics and univariate regression of Likert Scale scores.-RESULTS: Survey respondents represented 105 of 194 World Health Organization member countries (54.1%; 391 respondents, 162 from high-income countries and 229 from low-and middle-income countries [LMICs]). The most agreed on statement was that task sharing is preferred to task shifting. There was broad consensus that both task shifting and task sharing should require competency-based evaluation, standardized training endorsed by governing organizations, and maintenance of certification. When perspectives were stratified by income class, LMICs were significantly more likely to agree that task shifting is professionally disruptive to traditional training, task sharing should be a priority where human resources are scarce, and to call for additional TS/S regulation, such as certification and formal consultation with a neurosurgeon (in person or electronic/telemedicine).-CONCLUSIONS: Both LMIC and high-income countries agreed that task sharing should be prioritized over task shifting and that additional recommendations and regulations could enhance care. These data invite future discussions on policy and training programs.

Spine, May 20, 2013

Prospective clinical study. Compare fusion rates between recombinant human bone morphogenetic pro... more Prospective clinical study. Compare fusion rates between recombinant human bone morphogenetic protein-2 (rhBMP-2) and iliac crest bone graft (ICBG) with rhBMP-2 and local bone graft (LBG) (±bone graft extenders) in posterolateral fusion. Previous reports have shown higher fusion rates when adding rhBMP-2 to ICBG in lumbar posterolateral fusion, compared with ICBG alone. We compared the fusion success rates between rhBMP-2 delivered with ICBG versus that with LBG. Fusion rates were compared in patients with degenerative spondylolisthesis (1-2 levels) with accompanying lumbar stenosis. RhBMP-2 (INFUSE, Medtronic) was delivered on an absorbable collagen sponge (6 mg/side at 1.5 mg/mL) with ICBG alone or with LBG wrapped inside the sponge. Thin slice computed tomographic scans were assessed at 6, 12, and 24 months. In a consecutive series, 16 patients (30 levels) received ICBG with rhBMP-2 and 35 patients (49 levels) received LBG with rhBMP-2. For the ICBG cohort, 80.0%, 93.4%, 96.7% of levels were fused at 6, 12, and 24 months. In contrast, for the local bone with rhBMP-2 cohort, 87.7%, 98.0%, and 98.0% were fused at 6, 12, and 24 months. There was no statistically significant difference in fusion success rates between the 2 groups at any time point. As for fusion quality, the fusion mass showed superior quality in ICBG group than in the local bone group at each time point. This study validates the high fusion success rates previously reported by adding rhBMP-2 to ICBG and shows that local bone may be safely substituted for ICBG in 1- to 2-level posterolateral fusion. The fusion rates were comparable. The avoidance of ICBG harvest has implications for operative time, blood loss, and morbidity. Lastly, this is the first study that directly compares the fusion success rate and quality using local bone with rhBMP-2 versus ICBG with rhBMP-2 at various times. 4.

American Academy of Orthopaedic Surgeon, 2011

The incidence of anterior lumbar surgery is increasing. Although adverse events are uncommon, sev... more The incidence of anterior lumbar surgery is increasing. Although adverse events are uncommon, several have been described. Complications can be categorized based on the time of occurrence (ie, intraoperative, postoperative), patient positioning, surgical exposure, and spinal procedure. Notable approach-related complications involve vascular, visceral, and neural structures. Abdominal complications have been reported. Clinically significant complications related to spinal decompression and reconstruction consist primarily of neurologic injuries and graft- and device-related problems. The rate of complications is higher in the setting of revision anterior surgery than with initial anterior lumbar surgery. A thorough understanding of the complications associated with anterior lumbar surgery will aid in prevention, recognition, and management of these rare problems. The assistance of a vascular, neurologic, or general surgeon may be helpful in avoiding or effectively managing complications.

American Academy of Orthopaedic Surgeon, 2010

The orthopaedic patient on chronic anticoagulation therapy is at risk of thromboembolism and hemo... more The orthopaedic patient on chronic anticoagulation therapy is at risk of thromboembolism and hemorrhage in the perioperative period. To establish the most effective anticoagulation regimen, patients should be stratified according to the risk of arterial or venous thromboembolism. Timing of surgery, thromboembolic risk, and bleeding risk should be considered when developing an anticoagulation protocol. Retrievable inferior vena cava filters may be a viable alternative to bridging therapy in patients at high risk of venous thromboembolism and/or bleeding.

Echocardiography is a key assessment tool for the evaluation of cardiac structure and function. T... more Echocardiography is a key assessment tool for the evaluation of cardiac structure and function. Three dimensional echocardiography allows an accurate view of the entire mitral valvular apparatus and transvalvular jets, helps in identifying the mechanism of mitral regurgitation and in turn, aids in deciding the most favorable type and timing of surgical treatment. PURPOSE: To evaluate the feasibility of real – time three-dimensional (3D) transthoracic echocardiography (TTE) in reconstruction of mitral valve for complete diagnosis of the mitral regurgitation (MR). PATIENT POPULATION • 40 patients with mitral regurgitation referred for surgery • All were evaluated by 2D and 3D TTE EXCLUSION CRITERIA Inadequate echocardiographic images, movement artifacts caused by coughing or hiccough, difficulty with ECG registration and equipment failure STUDY PROTOCOL • Complete transthoracic echocardiographic study 2D and 3D -Vivid 7 and Sonos 7500 ultrasound units with S4 and respectively S3 secto...