• Title/Summary/Keyword: Basu

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A frequency tracking semi-active algorithm for control of edgewise vibrations in wind turbine blades

  • Arrigan, John;Huang, Chaojun;Staino, Andrea;Basu, Biswajit;Nagarajaiah, Satish
    • Smart Structures and Systems
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    • v.13 no.2
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    • pp.177-201
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    • 2014
  • With the increased size and flexibility of the tower and blades, structural vibrations are becoming a limiting factor towards the design of even larger and more powerful wind turbines. Research into the use of vibration mitigation devices in the turbine tower has been carried out but the use of dampers in the blades has yet to be investigated in detail. Mitigating vibrations will increase the design life and hence economic viability of the turbine blades and allow for continual operation with decreased downtime. The aim of this paper is to investigate the effectiveness of Semi-Active Tuned Mass Dampers (STMDs) in reducing the edgewise vibrations in the turbine blades. A frequency tracking algorithm based on the Short Time Fourier Transform (STFT) technique is used to tune the damper. A theoretical model has been developed to capture the dynamic behaviour of the blades including the coupling with the tower to accurately model the dynamics of the entire turbine structure. The resulting model consists of time dependent equations of motion and negative damping terms due to the coupling present in the system. The performances of the STMDs based vibration controller have been tested under different loading and operating conditions. Numerical analysis has shown that variation in certain parameters of the system, along with the time varying nature of the system matrices has led to the need for STMDs to allow for real-time tuning to the resonant frequencies of the system.

Impact of spar-nacelle-blade coupling on the edgewise response of floating offshore wind turbines

  • Dinh, Van-Nguyen;Basu, Biswajit;Nielsen, Soren R.K.
    • Coupled systems mechanics
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    • v.2 no.3
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    • pp.231-253
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    • 2013
  • The impact of spar-nacelle-blade coupling on edgewise dynamic responses of spar-type floating wind turbines (S-FOWT) is investigated in this paper. Currently, this coupling is not considered explicitly by researchers. First of all, a coupled model of edgewise vibration of the S-FOWT considering the aerodynamic properties of the blade, variable mass and stiffness per unit length, gravity, the interactions among the blades, nacelle, spar and mooring system, the hydrodynamic effects, the restoring moment and the buoyancy force is proposed. The aerodynamic loads are combined of a steady wind (including the wind shear) and turbulence. Each blade is modeled as a cantilever beam vibrating in its fundamental mode. The mooring cables are modeled using an extended quasi-static method. The hydrodynamic effects calculated by using Morison's equation and strip theory consist of added mass, fluid inertia and viscous drag forces. The random sea state is simulated by superimposing a number of linear regular waves. The model shows that the vibration of the blades, nacelle, tower, and spar are coupled in all degrees of freedom and in all inertial, dissipative and elastic components. An uncoupled model of the S-FOWT is then formulated in which the blades and the nacelle are not coupled with the spar vibration. A 5MW S-FOWT is analyzed by using the two proposed models. In the no-wave sea, the coupling is found to contribute to spar responses only. When the wave loading is considered, the coupling is significant for the responses of both the nacelle and the spar.

Diverse characters of Brennan's paw incision model regarding certain parameters in the rat

  • Kumar, Rahul;Gupta, Shivani;Gautam, Mayank;Jhajhria, Saroj Kaler;Ray, Subrata Basu
    • The Korean Journal of Pain
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    • v.32 no.3
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    • pp.168-177
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    • 2019
  • Background: Brennan's rodent paw incision model has been extensively used for understanding mechanisms underlying postoperative pain in humans. However, alterations of physiological parameters like blood pressure and heart rate, or even feeding and drinking patterns after the incision have not been documented as yet. Moreover, though eicosanoids like prostaglandins and leukotrienes contribute to inflammation, tissue levels of these inflammatory mediators have never been studied. This work further investigates the antinociceptive effect of protein C after intra-wound administration. Methods: Separate groups of Sprague-Dawley rats were used for quantitation of cyclooxygenase (COX) activity and leukotriene B4 level by enzyme-linked immunosorbent assay, as well as estimation of cardiovascular parameters and feeding and drinking behavior after paw incision. In the next part, rats were subjected to incision and $10{\mu}g$ of protein C was locally administered by a micropipette. Both evoked and non-evoked pain parameters were then estimated. Results: COX, particularly COX-2 activity and leukotriene B4 levels increased after incision. Hemodynamic parameters were normal. Feeding and drinking were affected on days 1 and 3, and on day 1, respectively. Protein C attenuated non-evoked pain behavior alone up to day 2. Conclusions: Based upon current observations, Brennan's rodent paw incision model appears to exhibit a prolonged period of nociception similar to that after surgery, with minimal interference of physiological parameters. Protein C, which is likely converted to activated protein C in the wound, attenuated the guarding score, which probably represents pain at rest after surgery in humans.

Can platelet-rich plasma injections provide better pain relief and functional outcomes in persons with common shoulder diseases: a meta-analysis of randomized controlled trials

  • Barman, Apurba;Mishra, Archana;Maiti, Rituparna;Sahoo, Jagannatha;Thakur, Kaustav Basu;Sasidharan, Sreeja Kamala
    • Clinics in Shoulder and Elbow
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    • v.25 no.1
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    • pp.73-89
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    • 2022
  • Background: To evaluate the efficacy of autologous platelet-rich plasma (PRP) injections in the treatment of common shoulder diseases. Methods: The PubMed, Medline, and Central databases and trial registries were searched from their inception to October 2020 for randomized controlled trials of autologous PRP injections for shoulder diseases versus placebo or any control intervention. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed in the selection, analysis, and reporting of findings. The primary outcome was pain intensity (visual analog scale), and secondary outcomes were changes in function and quality of life (QoL). Results: A total of 17 randomized controlled trials of PRP versus control were analyzed. From 8-12 weeks to ≥1 year, PRP injections were associated with better pain relief and functional outcomes than control interventions. PRP injections were also associated with greater QoL, with an effect size of 2.61 (95% confidence interval, 2.01-14.17) at medium-term follow-up. Compared with placebo and corticosteroid injections, PRP injections provided better pain relief and functional improvement. In subgroup analyses, trials in which PRP was prepared by the double centrifugation technique, the platelet concentration in the PRP was enriched ≥5 times, leucocyte-rich PRP was used, or an activating agent was used before application reported the most effective pain relief at 6-7 months. Conclusions: PRP injections could provide better pain relief and functional outcomes than other treatments for persons presenting with common shoulder diseases. PRP injections have a greater capacity to improve shoulder-related QoL than other interventions.

Utility of Subjective Global Nutritional Assessment Tool for the Assessment of Malnutrition in Pediatric Patients with Chronic Liver Disease

  • Anwesha Ray;Srikanta Basu;Praveen Kumar
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.26 no.6
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    • pp.346-354
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    • 2023
  • Purpose: Approximately 30% of children with chronic liver disease (CLD) are malnourished. However, proper assessment of their nutritional status is difficult. The subjective global nutritional assessment (SGNA) is a comprehensive approach that uses nutrition-focused history and examination, followed by grading of malnourishment. We aimed to study the prevalence of malnutrition in children with CLD using the SGNA tool. Methods: This cross-sectional observational study included patients aged <18 years with CLD. Nutritional assessments were recorded using SGNA tool. Conventional anthropometric measurements were performed and corroborated with nutritional status using SGNA tool. Results: A total of 85 children with CLD and mean age of 62 months were enrolled in this study. The prevalence of malnourished children according to SGNA was 34%; 22% were moderately malnourished and 12% were severely malnourished. We found statistically significant differences in anthropometric parameters among the three groups. A moderate degree of agreement was found between SGNA and weight-for-age (W/A) (p=0.020), mid-upper arm circumference (MUAC) (p<0.001), and triceps skin-fold thickness (TSF)-for-age (p=0.029). Furthermore, a fair degree of agreement was found between height-for-age (H/A) (p=0.001) and weight-for-height (W/H) (p<0.001). The sensitivity of W/A for detecting malnutrition was 93%, H/A was 90%, MUAC was 86%, and TSF was 88%. The sensitivity was much lower for W/H and body mass index for age (55% for both). Conclusion: In our study, more than one-third of children with CLD were malnourished. Nutritional assessment using SGNA is a reliable method for evaluating nutritional status and is significantly correlated with common anthropometric measurements.

A Study on the Effect of the Thematic Audit Review on Conservative Accounting of Unbilled Revenue (테마감리가 미청구공사의 보수적 회계처리에 미치는 영향에 관한 연구)

  • Park, Yeon Ho;Um, Jae Yeon;Jeon, Seong Il
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.16 no.2
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    • pp.177-188
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    • 2021
  • On December 2015, Financial Supervisory Service(FSS) announced the four key thematic audit review areas, one of them is an appropriation of unbilled revenue. Accounting of unbilled revenue is intertwined with a percentage of completion, that is concerned about discretionary decision by manager. Therefore, if manager motivated by income-increasing manipulation is exaggerating percentage of completion, unbilled revenue is excessively recognized. This problem is caused the serious accounting issues(e.g., shock at a loss for 2013 fiscal year by some construction firms, malpractice of accounting in order-made production industry). Distrust of accounting was grown because the shipbuilding and construction industries successively went poor management and bad accounting of them is revealed. Those accounting issues were the trigger for problem recognition of unbilled revenue, they were background for the designation of appropriation unbilled revenue as thematic audit review areas by FSS. Therefore, this study verified effectiveness of thematic audit review by empirically analyzing whether designation of thematic audit review makes the firm increases conservative behavior. Conservative accounting is estimated by using Basu(1997) model. We analyzed the effect of the thematic audit review on conservative accounting of unbilled revenue by comparing with reflecting unbilled revenue or not. The sample for test consists of firm-years the manufacturing and construction industries from 2012 to 2017. The test results of this study suggested that the conservative accounting of unbilled revenue after designation of the thematic audit review was significantly increased. We also tested again by classifying whether or not it is construction industry. We found that construction industry is more conservative than the other industry only for the designated year of the thematic audit review, otherwise there was not any evidence for significantly increasing conservatism. This study contributes to the literature by empirically analysing relationship of the unbilled revenue to the thematic audit review from the perspective of the conservatism and verifying effectiveness of the thematic audit review.

Chronic persistent post-surgical pain following staging laparotomy for carcinoma of ovary and its relationship to signal transduction genes

  • Saxena, Ashok Kumar;Chilkoti, Geetanjali T;Chopra, Anand K;Banerjee, Basu Dev;Sharma, Tusha
    • The Korean Journal of Pain
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    • v.29 no.4
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    • pp.239-248
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    • 2016
  • Background: The present study was undertaken to evaluate the incidence of chronic persistent post-surgical pain (CPPP) and the role of signal transduction genes in patients undergoing staging laparotomy for carcinoma ovary. Methods: The present observational study was undertaken following institutional ethical committee approval and informed consent from all the participants. A total 21 patients of ASA grade I to III with age 20-70 years, scheduled for elective staging laparotomy for carcinoma ovary were included. Patients were excluded if had other causes of pain, cognitive dysfunction or chronic neurological disorders. Statistical analysis of pool data was done using SPSS version-17. For various scales like GPE, PDQ, NPSI, the visual analogue scale (VAS), global perceived effect (GPE), the pain DETECT questionnaire (PDQ), and neuropathic pain symptoms inventory (NPSI), one factor repaeted measure ANOVA applied with simple contrast with baseline as on post-operative day 1 (considered as reference and compared with subsequent time-interval), and the P values were adjusted according to "Bonferroni adjustments". In patients with CPPP, the ${\Delta}ct$ values of mRNA expressions of genes at the end of postoperative day 90 were compared with the baseline control values by one factor repeated ANOVA. P value < 0.005 significant. Results: The present study demonstrates 38.1% (8 out of 21 patients) incidence of CPPP. The functional status and quality of life as were observed to be significantly diminished in all patients with chronic pain. An up-regulation in the mRNA expression of signal transduction and a positive correlation was noted between the mRNA expression of signal transduction genes and VAS score in all patients with CPPP at the end of postoperative day 90. Conclusions: The reported incidence of CPPP in patients with carcinoma ovary was 38.1%. An up-regulation and positive correlation between mRNA expression of signal transduction genes and VAS score depicts its potential role in the pathogenesis of CPPP.

Using Implementation Science to Advance Cancer Prevention in India

  • Krishnan, Suneeta;Sivaram, Sudha;Anderson, Benjamin O.;Basu, Partha;Belinson, Jerome L;Bhatla, Neerja;D' Cruz, Anil;Dhillon, Preet K.;Gupta, Prakash C.;Joshi, Niranjan;Jhulka, PK;Kailash, Uma;Kapambwe, Sharon;Katoch, Vishwa Mohan;Kaur, Prabhdeep;Kaur, Tanvir;Mathur, Prashant;Prakash, Anshu;Sankaranarayanan, R;Selvam, Jerard M;Seth, Tulika;Shah, Keerti V;Shastri, Surendra;Siddiqi, Maqsood;Srivastava, Anurag;Trimble, Edward;Rajaraman, Preetha;Mehrotra, Ravi
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3639-3644
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    • 2015
  • Oral, cervical and breast cancers, which are either preventable and/or amenable to early detection and treatment, are the leading causes of cancer-related morbidity and mortality in India. In this paper, we describe implementation science research priorities to catalyze the prevention and control of these cancers in India. Research priorities were organized using a framework based on the implementation science literature and the World Health Organization's definition of health systems. They addressed both community-level as well as health systems-level issues. Community-level or "pull" priorities included the need to identify effective strategies to raise public awareness and understanding of cancer prevention, monitor knowledge levels, and address fear and stigma. Health systems-level or "push" and "infrastructure" priorities included dissemination of evidence-based practices, testing of point-of-care technologies for screening and diagnosis, identification of appropriate service delivery and financing models, and assessment of strategies to enhance the health workforce. Given the extent of available evidence, it is critical that cancer prevention and treatment efforts in India are accelerated. Implementation science research can generate critical insights and evidence to inform this acceleration.

Prevalence of Human Papillomavirus and Co-Existent Sexually Transmitted Infections among Female Sex Workers, Men having Sex with Men and Injectable Drug abusers from Eastern India

  • Ghosh, Ishita;Ghosh, Pramit;Bharti, Alok Chandra;Mandal, Ranajit;Biswas, Jaydip;Basu, Partha
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.3
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    • pp.799-802
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    • 2012
  • Background: Human papillomavirus (HPV) is a very common sexually transmitted disease affecting both men and women and is responsible for different ano-genital cancers in either sex. Co-existing sexually transmitted infections (STI) including HIV have been considered as important co-factors for carcinogenesis induced by HPV. The purpose of this study was to determine the prevalence of any HPV, HPV 16 and HPV 18 and also concomitant STIs among female sex workers (FSW), men having sex with men (MSM) and injectable drug users (IDU). Material and Method: This cross-sectional study was conducted among 45 FSWs, 26 MSMs and 58 IDUs who attended the STI or de-addiction clinics. Genital scrape samples collected from glans penis and coronal sulcus in males and cervical squamo-columnar junction in females were tested for HPV DNA by PCR using HPV L1 consensus primer. Type specific PCR to detect HPV 16 and 18 was done on the samples positive on consensus PCR. All participants were tested for associated STIs including HIV and hepatitis B and cervical cytology was done on all females. Results: Among the FSWs, HPV was detected in 73.3% and HPV 16 and 18 was detected in 25.7%. Though the HPV prevalence was similarly high among MSMs (69.2%) and IDUs (72.4%), the prevalence of HPV 16 and 18 was much lower in these groups compared to the FSWs. Prevalence of cervico-vaginal infection with Trichomonas vaginalis and syphilis was significantly higher in the HPV positive women compared to the HPV negative women. There was no statistically significant difference in the prevalence of other STIs among HPV positive and negative women and men. Conclusion: HPV infection is highly prevalent among FSW, MSM and IDUs. Trichomonas vaginalis infection is more frequent in HPV positive women.