Design of Safety Critical and Control Systems of Nuclear Power Plants using Petri Nets

Pooja Singh,Lalit Kumar Singh 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.5

Non-functional requirements plays a critical role in designing variety of applications domain ranges fromsafety-critical systems to simple gaming applications. Performance is one of the crucial non-functionalrequirement, especially in control and safety systems, that validates the design. System risk can bequantified as a product of probability of system failure and severity of its impact. In this paper, we devisea technique to do the performance analysis of safety critical and control systems and to estimate performancebased risk factor. The technique elaborates Petri nets to estimate performability to ensuresystem dependability requirements. We illustrate the technique on a case study of Nuclear Power Plantsystem. The technique has been validated on 17 safety critical and control systems of Nuclear PowerPlant.

Instrumentation and control systems design for nuclear power plant: An interview study with industry practitioners

Singh, Pooja,Singh, Lalit Kumar Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.11

Instrumentation and Control systems (I&C) play a significant role in nuclear power plants (NPP) and other safety critical systems (SCS). We have conducted a rigorous study and discussions with experienced practitioners worldwide the strategy for the development of I&C systems to investigate the several aspects related to their dependability. We discussed with experienced practitioners that work on nuclear domain with the intention of knowing their approach, they use day-to-day for the development of such systems. The aim of this research is to obtain to provide guidance to those building I&C systems of NPP and have implications on state engineering licensure boards, in the determination of legal liability, and in risk assessment for policymakers, corporate governors, and insurance executives.

Adsorption behaviour of o-hydroxy acetophenone benzoyl hydrazone on mild steel/hydrochloric acid interface

Ashish Kumar Singh,Pooja Singh 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.21 No.1

The effect of synthesised o-hydroxy acetophenone benzoyl hydrazone (HABH) on the corrosion of mildsteel in 1 MHCl was investigated using potentiodynamic polarisation (PDP), electrochemical impedancespectroscopy (EIS), thermogravimetric analysis, contact angle measurement and weight loss methods. The inhibition efficiency of HABH increases with surface roughness of emery paper up to 800 grits andthereafter it decreases with additional increase in surface roughness. TGA results also indicated that theinhibitor film on the surface had a relatively good thermal stability. The adsorption behaviour of HABH isexperimentally investigated by contact angle measurement of acid solution on metal surface.

Energy and nutrient recovery from agro-wastes: Rethinking their potential possibilities

Barkha Vaish,Vaibhav Srivastava,Prabhat Kumar Singh,Pooja Singh,Rajeev Pratap Singh 대한환경공학회 2020 Environmental Engineering Research Vol.25 No.5

Agricultural sector has inescapably drawn attention towards itself due to growing concern over population explosion, changing climate and depletion of resources. Advancements in technology have caused rapid boost in farm productivity and hence huge production of agro-wastes. There have been massive deteriorating impacts of agro-wastes on existing environmental conditions, creating wide scale environmental pollution as well as biodiversity loss. Since, agro-wastes have huge potential in the form of energy and nutrient recovery (ENR), amalgamations of different technologies would promote sustainability. ENR not only adjoins an added profitable product but also facilitates to close environmental nutrient cycles. This provides a substitute to existing unsustainable approaches that are energy demanding and reliant on nonrenewable sources of energy. This review underpins why ENR from agro-waste must be key concern in production of array of higher value products.

Aedes aegypti container preference for oviposition and its possible implications for dengue vector surveillance in Delhi, India

Pooja Prasad,Suman Lata,Sanjeev Kumar Gupta,Pawan Kumar,Rekha Saxena,Deepak Kumar Arya,Himmat Singh 한국역학회 2023 Epidemiology and Health Vol.45 No.-

OBJECTIVES: Dengue is a mosquito-borne viral disease globally transmitted by Aedes aegypti. The most effective method to prevent the transmission of the disease is proficient vector control. Understanding the breeding behaviour of the responsible vectors is very pertinent in this regard; therefore, the present study was conducted to understand Ae. aegypti behaviour regarding the selection of containers for oviposition in the megacity of Delhi. METHODS: A household survey in different localities within Delhi was carried out during 2018-2019. All available containers were inspected for the presence of immature Ae. aegypti. In entomological surveillance, the ovipositional preference of Aedes was computed using the breeding preference ratio, container index in the field, and laboratory settings, and associations of dengue cases with monthly variation in environmental factors and container type were also calculated. RESULTS: The household larval survey in 40 localities showed that 40% of 27,776 water-holding containers in 3,400 houses were plastic, followed by overhead tanks (26.2%), and coolers (12.1%). The most preferred breeding habitat was clay pots (9.3%), followed by metallic containers (8.5%) and solid waste (7.1%). A laboratory-based study showed that Aedes preferred clay containers (81.8%) over 4 other types of containers (plastic, paper, metal, and glass). CONCLUSIONS: The present study provides a rationale for using clay containers as a possible surveillance tool (ovitraps) or as a vector control tool. This information might aid researchers in developing novel traps and targeting preferred containers for larval control activities during transmission and non-transmission seasons.

An Improved Approach to Ranking Web Documents

Pooja Gupta,Sandeep K. Singh,Divakar Yadav,A. K. Sharma 한국정보처리학회 2013 Journal of information processing systems Vol.9 No.2

Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score

An Improved Approach to Ranking Web Documents

Gupta, Pooja,Singh, Sandeep K.,Yadav, Divakar,Sharma, A.K. Korea Information Processing Society 2013 Journal of information processing systems Vol.9 No.2

Ranking thousands of web documents so that they are matched in response to a user query is really a challenging task. For this purpose, search engines use different ranking mechanisms on apparently related resultant web documents to decide the order in which documents should be displayed. Existing ranking mechanisms decide on the order of a web page based on the amount and popularity of the links pointed to and emerging from it. Sometime search engines result in placing less relevant documents in the top positions in response to a user query. There is a strong need to improve the ranking strategy. In this paper, a novel ranking mechanism is being proposed to rank the web documents that consider both the HTML structure of a page and the contextual senses of keywords that are present within it and its back-links. The approach has been tested on data sets of URLs and on their back-links in relation to different topics. The experimental result shows that the overall search results, in response to user queries, are improved. The ordering of the links that have been obtained is compared with the ordering that has been done by using the page rank score. The results obtained thereafter shows that the proposed mechanism contextually puts more related web pages in the top order, as compared to the page rank score.

Mechanistic Insight into the Chemical Exfoliation and Functionalization of Ti₃C₂ MXene

Srivastava, Pooja,Mishra, Avanish,Mizuseki, Hiroshi,Lee, Kwang-Ryeol,Singh, Abhishek K. American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.36

<P>MXene, a two-dimensional layer of transition metal carbides/nitrides, showed great promise for energy storage, sensing, and electronic applications. MXene are chemically exfoliated from the bulk MAX phase; however, mechanistic understanding of exfoliation and subsequent functionalization of these technologically important materials is still lacking. Here, using density-functional theory we show that exfoliation of Ti3C2 MXene proceeds via HF insertion through edges of Ti3AlC2 MAX phase. Spontaneous dissociation of HF and subsequent termination of edge Ti atoms by H/F weakens Al-MXene bonds. Consequent opening of the interlayer gap allows further insertion of HF that leads to the formation of AlF3 and H-2, which eventually come out of the MAX, leaving fluorinated MXene behind. Density of state and electron localization function shows robust binding between F/OH and Ti, which makes it very difficult to obtain controlled functionalized or pristine MXene. Analysis of the calculated Gibbs free energy (Delta G) shows fully fluorinated MXene to be lowest in energy, whereas the formation of pristine MXene is thermodynamically least favorable. In the presence of water, mixed functionalized Ti3C2Fx(OH)(1-x) (x ranges from 0 to 1) MXene can be obtained. The Delta G values for the mixed functionalized MXenes are very close in energy, indicating the random and nonuniform functionalization of MXene. The microscopic understanding gained here unveils the challenges in exfoliation and controlling the functionalization of MXene, which is essential for its practical application.</P>

Sensitivity Evaluation of a Multi-Layered Heterostructure Blue Phosphorene/MoS 2 Surface Plasmon Resonance Based Fiber Optic Sensor: A Simulation Study

Sachin Singh,A. K. Sharma,Pooja Lohia,D. K. Dwivedi 한국전기전자재료학회 2022 Transactions on Electrical and Electronic Material Vol.23 No.3

In this study, an angular interrogation technique has been used for modeling a highly sensitive surface plasmon resonance (SPR)based biosensor. The large surface area of the heterostructure of the blue phosphorene (BP/MoS 2 ) layer facilitates the biomolecules absorption. A four-layer Kretschmann model of the SPR biosensor containing the BP/MoS 2 heterostructure with a gold layer is proposed. Compared to the traditional gold fi lmbased SPR biosensors, the sensitivity of the proposed SPR biosensor has been signifi cantly improved. An enhanced sensitivity 224.57°/RIU has been achieved by optimizing the proposed structure with 50 nm thick gold layer and a monolayer of heterostructure BP/MoS 2 with a thickness of 0.75 nm. Moreover, the proposed BP/MoS 2 heterostructure off ers extremely small FWHM, high detection accuracy, and highquality factor parameters. The highest sensitivity of 252°/RIU was found with two-layers of BP/MoS 2 heterostructure confi guration. It is observed that, compared to previously reported sensitivity, the proposed SPR biosensor shows better results.

Corrosive poisoning and its implications on pediatric airways

Payal Yashwant Singh,Sogal P Sachin,CS Pooja 대한마취통증의학회 2023 Korean Journal of Anesthesiology Vol.76 No.6

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