Bi‑directional non‑isolated impedance converter for extra low‑voltage battery system safety

Aditya Narula,Vishal Verma 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.8

For bi-directional power converters, modularity, low leakage currents, low ripple, and a simple bi-directional control that utilizes storage eff ectively with low-voltage stress are required. This paper proposes a new configuration for converters that meet all of the above requirements to realize a robust converter for both vehicle to low-voltage DC microgrid (V2G) and low-voltage DC microgrid (LVDC-MG) to vehicle (G2V) technologies. The proposed power-dense modular-impedance source configuration employs coupled inductors, which ensures a power-dense modular architecture configuration with low current ripple and negligible leakage currents. The new auxiliary boost capability of the impedance source provides a wide operating range. A unifi ed bi-directional control algorithm enables operation to/from battery stacks at customized rates, based on the state of charge (SoC). Based on the requirements of the control scheme, this automatically invokes the use of the impedance network to cater to the low charge conditions of the battery stack or the transient conditions on the LVDC microgrid. The proposed bi-directional converter is tested through both simulations and experimental studies on a developed prototype to confirm high efficiency operations over a wide range of duty cycles.

Comparative Analysis of DWT and DWT-SVD Watermarking Techniques in RGB Images

Neha Narula,Deepak Sethi,Partha Pratim Bhattacharya 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.4

Digital watermarking is an application associated with copyright protection. Any digital object can be used as a carrier to carry information. If the information is related to object then it is known as a watermark which can be visible or invisible. In the era of digital information, there are multiple danger zones like copyright and integrity violation of digital object. In case of any dispute during violation, content creator can prove ownership by recovering the watermark. In this paper, a comparative study of two most recent digital watermarking techniques namely DWT and DWT-SVD over RGB images is presented. In case of DWT (Discrete Wavelet Transform) watermarking technique, decomposition of the original image is done to embed the watermark and in case of DWT-SVD watermarking technique, firstly original image is decomposed according to DWT and then watermark is embedded in singular values obtained by applying SVD (Singular Value Decomposition). The performances of the proposed techniques are compared on the basis of PSNR values.

Experimental and Kinetic Studies of Esterification of Glycerol Using Combustion Synthesized SO₄^2-/CeO₂-Al₂O₃

Veluturla, Sravanthi,Narula, Archna,Rao, D. Subba,Indraja., S,Kulkarni, Rajeswari. M. The Korean Institute of Chemical Engineers 2018 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.56 No.4

An increase in the global production of biodiesel has resulted in the newfound significance of its byproduct, glycerol. The synthesis of acetins is an economical avenue to enhance the value of glycerol derived from biodiesel. WE developed an eco-friendly process for the synthesis of fuel additives from glycerol using a mixed oxide $SO{_4}^{2-}/CeO_2-Al_2O_3$ as catalyst. The $CeO_2-Al_2O_3$ mixed oxide was synthesized by the combustion method and then sulfated. The characterization of the catalyst was by means of XRD, BET, FTIR, and SEM. The influence of temperature, mole ratio and catalyst loading on yield and selectivity of the acetins was studied for the esterification of glycerol. The reaction rate constants ($k_1$, $k_2$ and $k_3$) were estimated using optimization method in MAT lab, and the activation energies ($E_1$, $E_2$ and $E_3$) were determined by the Arrhenius equation. Furthermore, a kinetic model was developed.

Platelet-rich fibrin along with a modified minimally invasive surgical technique for the treatment of intrabony defects: a randomized clinical trial

Ahmad, Nabila,Tewari, Shikha,Narula, Satish Chander,Sharma, Rajinder Kumar,Tanwar, Nishi Korean Academy of Periodontology 2019 Journal of Periodontal & Implant Science Vol.49 No.6

Purpose: The modified minimally invasive surgical technique (M-MIST) has been successfully employed to achieve periodontal regeneration. Platelet-rich fibrin (PRF) is known to enhance wound healing through the release of growth factors. This study aimed to observe the outcomes of periodontal surgery when M-MIST was used with or without PRF for the treatment of isolated intrabony defects. Methods: This randomized clinical trial was conducted on 36 systemically healthy patients, who had chronic periodontitis associated with a single-site buccal probing pocket depth (PPD) and clinical attachment level of ≥5 mm. Patients were randomly divided into 2 groups: the test group treated with M-MIST and PRF, and the control group treated with M-MIST alone. The primary periodontal parameters analyzed were PPD, relative attachment level (RAL), and relative gingival margin level. The radiographic parameters analyzed were change in alveolar crest position (C-ACP), linear bone growth (LBG), and percentage bone fill (%BF). Patients were followed up to 6 months post-surgery. Results: Intragroup comparisons at 3 and 6 months showed consistently significant improvements in PPD and RAL in both the groups. In intergroup comparisons, the improvement in PPD reduction, gain in RAL, and the level of the gingival margin was similar in both groups at 3 and 6 months of follow-up. Furthermore, an intergroup comparison of radiographic parameters also demonstrated similar improvements in C-ACP, LBG, and %BF at 6 months of follow-up. Conclusions: M-MIST with or without PRF yielded comparable periodontal tissue healing in terms of improvements in periodontal and radiographic parameters. Further investigation is required to confirm the beneficial effects of PRF with M-MIST.

Superior Vena Cava Echocardiography as a Screening Tool to Predict Cardiovascular Implantable Electronic Device Lead Fibrosis

S. Jeffrey Yakish,Arvin Narula,Robert Foley,Andrew Kohut,Steven Kutalek 한국심초음파학회 2015 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.23 No.1

Background: Currently there is no noninvasive imaging modality used to risk stratify patients requiring lead extractions. Wereport the novel use of superior vena cava (SVC) echocardiography to identify lead fibrosis and complex cardiac implantableelectronic device (CIED) lead extraction. With an aging population and expanding indications for cardiac device implantation,the ability to deal with the complications associated with chronically implanted device has also increased. Methods: This was a retrospective analysis of Doppler echocardiography recorded in our outpatient Electrophysiology/DeviceClinic office over 6 months. Images from 109 consecutive patients were reviewed. Results: 62% (68/109) did not have a CIED and 38% (41/109) had a CIED. In patients without a CIED, 6% (4/68) displayedturbulent color flow by Doppler in the SVC, while 22% (9/41) of patients with a CIED displayed turbulent flow. Fisher’s exacttest found a statistically significant difference between the two groups (p value < 0.05). The CIED group was subdivided into 2groups based on device implant duration (< 2 years vs. ≥ 2 years). Of the CIED implanted for ≥ 2 years, 27% (9/33) hadturbulent flow in the SVC by Doppler, while no patients (0/8) with implant durations < 2 years demonstrated turbulent flow. Nine patients underwent subsequent lead extraction. A turbulent color pattern successfully identified all 3 patients that hadsignificant fibrosis in the SVC found during extraction. Conclusion: Our data suggests that assessing turbulent flow using color Doppler in the SVC may be a valuable noninvasivescreening tool prior to lead extraction in predicting complex procedures.

Electrochemical Sensing of Cd(II) Ions Using Polypyrrole hybrid with meso-tetra(4-carboxyphenyl)porphyrin

Shruti Peshoria,Anudeep Kumar Narula 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Determination of caffeic acid using fabricated nano-bio-hybrid films electrode

Salma Khan,Anudeep K Narula 한국고분자학회 2016 한국고분자학회 학술대회 연구논문 초록집 Vol.41 No.2

Impact of iron deficiency anemia on chronic periodontitis and superoxide dismutase activity: a cross-sectional study

Chakraborty, Souvik,Tewari, Shikha,Sharma, Rajinder Kumar,Narula, Satish Chander,Ghalaut, Pratap Singh,Ghalaut, Veena Korean Academy of Periodontology 2014 Journal of Periodontal & Implant Science Vol.44 No.2

Purpose: Both chronic periodontitis (CP) and iron deficiency anemia (IDA) induce oxidative stress in the body and cause an imbalance between reactive oxygen species and antioxidants, such as superoxide dismutase (SOD). This study explored the SOD enzyme activity of saliva and serum in CP patients with and without IDA and analyzed the impact of IDA on CP. Methods: A total of 82 patients were divided into four groups: control group (CG, 22), periodontally healthy IDA patients (IDA-PH, 20), CP patients (CP, 20), and IDA patients with CP (IDA-CP, 20). After clinical measurements and samplings, serum and salivary SOD levels were determined using an SOD assay kit. Results: IDA-CP patients exhibited a higher gingival index, bleeding on probing, probing pocket depth, and percentage (%) of sites with a clinical attachment loss (CAL) of ${\geq}6mm$ (P<0.008) than CP patients. The mean salivary and serum SOD levels were significantly lower in the IDA-PH, CP, and IDA-CP patients than in the CG group (P<0.008). A significant positive correlation between salivary and serum SOD activity was observed in IDA (P<0.05). Furthermore, serum and salivary SOD levels were significantly and negatively correlated with all periodontal parameters including the percentage of sites with CAL of 4-5 and ${\geq}6mm$ (P<0.05) except the significant correlation between salivary SOD activity and mean CAL and the percentage of sites with CAL of 4-5 mm (P>0.05) in these patients. Conclusions: Within the limits of this study, it may be suggested that IDA patients with chronic periodontitis have more periodontal breakdowns than patients with chronic periodontitis. Serum and salivary SOD activity levels were lower in the IDA-PH, CP and IDA-CP groups than in the CG. Iron deficiency anemia influenced the serum SOD activity but did not seem to affect the salivary SOD activity in these patients.

Is the Mongolian Health Sector Ready for a Sector-Wide Approach?

Anar Ulikpan,Tolib N. Mirzoev,Indermohan S. Narula 한국사회복지학회 2008 Asian Social Work and Policy Review Vol.2 No.2

Mongolia has experienced major social and economic changes since the early 1990s. Large-scalereforms have been introduced in all sectors over the last 10 years. Implementing health reformsrequires a more coordinated approach and the Mongolian health sector has been exploring anoption of implementing a Sector-Wide Approach (SWAp) to the health sector. This article aims todevelop and apply an analytical framework for assessing the feasibility of implementing SWAp inthe Mongolian health sector. Review of published and unpublished evidence at the national andinternational levels is undertaken and complemented by semi-structured interviews with keyrespondents from Mongolian Ministry of Health. A framework for assessing the feasibility ofSWAp in Mongolia has been developed which comprises the key elements and stages of developmentof SWAp in a particular context. This framework has been then applied to assess the feasibilityof implementing SWAp in the Mongolian health sector. The main SWAp elements are in place. Emerging central level capacity, increasing donor confidence and willingness to move towards sector-wide management is now becoming more evident in Mongolia. It looks like Mongolia is readyfor a national level government-led SWAp with the potential to implement a fully-fledged SWAp inthe health sector. The essential ground-work for starting a SWAp is in place, but further capacitystrengthening is needed. A framework for implementing health SWAp in Mongolia is suggested. It is important to consider the improvement of existing government systems in future SWAparrangements to ensure local ownership.

A Study on Fake News Subject Matter, Presentation Elements, Tools of Detection, and Social Media Platforms in India

Kanozia, Rubal,Arya, Ritu,Singh, Satwinder,Narula, Sumit,Ganghariya, Garima Center for Asian Public Opinion ResearchCollaborat 2021 Asian journal for public opinion research Vol.9 No.1

This research article attempts to understand the current situation of fake news on social media in India. The study focused on four characteristics of fake news based on four research questions: subject matter, presentation elements of fake news, debunking tool(s) or technique(s) used, and the social media site on which the fake news story was shared. A systematic sampling method was used to select a sample of 90 debunked fake news stories from two Indian fact-checking websites, Alt News and Factly, from December 2019 to February 2020. A content analysis of the four characteristics of fake news stories was carefully analyzed, classified, coded, and presented. The results show that most of the fake news stories were related to politics in India. The majority of the fake news was shared via a video with text in which narrative was changed to mislead users. For the largest number of debunked fake news stories, information from official or primary sources, such as reports, data, statements, announcements, or updates were used to debunk false claims.