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Phosphorus partitioning and recovery of low-phosphorus iron-rich compounds through physical separation of Linz-Donawitz slag

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International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 751-759页

作者： Dilip Makhija Rajendra kumar Rath Kaushik Chakravarty Abhay Shankar Patra Asim kumar Mukherjee akhilesh kumar Dubey Research and Development Division Tata Steel Ltd. Mineral Processing Division CSIR-National Metallurgical Laboratory Raw Material Blending and Bedding Section Tata Steel Ltd.

The Linz-Donawitz（LD） steelmaking process produces LD slag at a rate of about 125 kg/t. After metallic scrap recovery, the non-metallic LD slag is rejected because its physical/chemical properties are unsuitable for recycling. X-ray diffraction（XRD） studies have indicated that non-metallic LD slag contains a substantial quantity of mineral phases such as di- and tricalcium silicates. The availability of these mineral phases indicates that LD slag can be recycled by iron（Fe）-ore sintering. However, the presence of 1.2wt% phosphorus（P） in the slag renders the material unsuitable for sintering operations. Electron probe microscopic analysis（EPMA） studies indicated concentration of phosphorus in dicalcium silicate phase as calcium phosphate. The Fe-bearing phases（i.e., wustite and dicalcium ferrite） showed comparatively lower concentrations of P compared with other phases in the slag. Attempts were made to lower the P content of LD slag by adopting various beneficiation techniques. Dry high-intensity magnetic separation and jigging were performed on as-received samples with particle sizes of 6 and 3 mm. Spiral separation was conducted using samples ground to sizes of less than 1 and 0.5 mm. Among these studies, grinding to 0.5 mm followed by spiral concentration demonstrated the best results, yielding a concentrate with about 0.75wt% P and 45wt% Fe.

关键词： steelmaking slag dephosphorization recycling

Friction and wear behavior of Cu-4 wt.％Ni-TiC composites under dry sliding conditions

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Friction 2017年第4期5卷 437-446页

作者： Pushkar JHA Rakesh kumar GAUTAM Rajnesh tyagi Department of Mechanical Engineering Indian Institute of Technology(Banaras Hindu University)Varanasi 221005India

The present study synthesized Cu-4 wt％ Ni matrix composites reinforced with different percentages of TiC (0,2,4,6,and 8 wt％) through high-energy ball milling,followed by compaction and *** friction and wear behavior was examined at four different normal loads of 5,10,15,and 20 N.A constant sliding speed of 1.25 m/s was maintained while sliding against a hardened counterface made of EN31 steel (HRC 60) under ambient conditions using a pin-on-disk test *** composite hardness increased until the addition of 4 wt％ of TiC,beyond which it was observed to *** a trend may be attributed to the TiC agglomeration in the composites containing relatively larger amounts of TiC (i.e.,6 and 8 wt％).The wear rate linearly increased with the ***,the composites exhibited a lower rate of wear than the matrix alloy,which may have resulted from the relatively higher hardness of *** observed friction and wear behavior has been explained on the basis of hardness and presence of the transfer layer on the worn surface and its nature,i.e.,loose or well *** of 4 wt％ TiC showed the optimum performance in terms of friction and wear caused by its higher hardness and ability to hold a transfer layer of a relatively larger thickness compared to the other *** wear mechanism for the Cu4Ni matrix alloy was a mix of adhesive and oxidative wear and primarily abrasive for the composites containing hard TiC particles.

关键词： sliding wear composites TiC particles friction

Probiotics media: significance, challenges, and future perspective - a mini review

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Food Production, Processing and Nutrition 2022年第1期4卷 211-223页

作者： Vijay kumar Bindu Naik akhilesh kumar Naresh Khanduri Sarvesh Rustagi Sanjay kumar Department of Biosciences Swami Rama Himalayan UniversitySwami Rama NagarJolly GrantDehradun248016UttarakhandIndia Department of Life Sciences Graphic Era(Deemed to Be)UniversityBell RoadClement Town DehradunUttarakhand248001India Department of Food Technology UCALSUttaranchal UniversityDehradunUttarakhandIndia

The health benefits associated with probiotics have increased their application in pharmaceutical formulations and functional food development. High production of probiotic biomass requires a cost-effective production method and nutrient media optimization. The biomass production of probiotics can be enhanced by optimizing growth parameters such as substrate, pH, incubation time, etc. For economical industrial production of probiotic biomass, it is required to design a new medium with low cost. Wastes from the food industries are promising components for the development of the low-cost medium. Industrial wastes such as cheese whey and corn steep liquor are excellent examples of reliable sources of nitrogen for the biomass production of probiotic bacteria. The increased yield of biomass reduced the cost of production. This review focuses on the importance of probiotic media for biomass production and its challenges.

关键词： Probiotics Media Health benefits Production

Critical review of EPS production, synthesis and composition for sludge flocculation

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Journal of Environmental Sciences 2018年第4期30卷 225-245页

作者： Klai Nouha Ram Saurabh kumar Sellamuthu Balasubramanian Rajeshwar Dayal tyagi Universite du Quebec Institut national de la Recherche Scientifique Centre Eau Terre & Environnement 490 de la CouronneQuebec G1K 9A9 Canada Institut Armand-Frappier 531 boul. des Prairies Laval Quebec H7V 1B7 Canada

Extracellular polymeric substances（EPS） produced by microorganisms represent biological macromolecules with unfathomable potentials and they are required to be explored further for their potential application as a bioflocculant in various wastewater sludge treatment. Although several studies already exist on biosynthetic pathways of different classical biopolymers like alginate and xanthan, no dedicated studies are available for EPS in sludge. This review highlights the EPS composition, functionality, and biodegradability for its potential use as a carbon source for production of other metabolites. Furthermore, the effect of various extraction methods（physical and chemical） on compositional, structural, physical and functional properties of microbial EPS has been addressed. The vital knowledge of the effect of extraction method on various important attributes of EPS can help to choose the suitable extraction method depending upon the intended use of EPS. The possible use of different molecular biological techniques for enhanced production of desired EPS was summarized.

关键词： Extracellular polymeric substances Metabolic pathways Extraction methods Flocculation properties

Dynamic parameters of vehicles under heterogeneous traffic stream with non-lane discipline:An experimental study

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Journal of Traffic and Transportation Engineering(English Edition) 2018年第5期5卷 386-405页

作者： Geetimukta Mahapatra akhilesh kumar Maurya Department of Civil Engineering Indian Institute of Technology Guwahati

On the heterogeneous and no lane disciplined traffic, the abreast maneuver of vehicles depends upon the driver behavior, vehicle type and most importantly the traffic parameters such as vehicle speed and acceleration. Hence, the drivers have two basic tasks while driving, first is to control the vehicle＇s position along longitudinal direction of motion and second is to control the vehicle＇s position along lateral direction i.e. the width of the roadway. The relation between the dynamic parameters （speed and lateral/longitudinal acceleration）, can very well represent the driving behavior of vehicles in mixed with weak or no lane disciplined traffic. Hence, the study of longitudinal and lateral control of vehicles in a comprehensive manner is necessary. In the present paper, driving behavior of vehicles are studied by analyzing longitudinal and lateral acceleration/deceleration （A/D） with operating speed of vehicles on different straight roadway sections. Data are collected from five major cities of India using GPS based instrument （Video-VBOX） mounted on five different type of vehicles. The probability distribution of longitudinal A/D and the lateral acceleration are analysed, and their relationship with operating speed of vehicles are studied on roads with a different number of lanes for different vehicle types. A two-term exponential and linear relationship with operating speed are observed for lateral and longitudinal A/D respectively.

关键词： Non-lane discipline traffic Mixed traffic Driving behavior Dynamic parameters Operating speed g-g diagram

A detailed study on trust management techniques for security and privacy in IoT:challenges,trends,and research directions

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高置信计算(英文) 2023年第2期3卷 71-82页

作者： Himani tyagi Rajendra kumar Santosh Kr Pandey Department of Computer Science Jamia Millia IslamiaNew Delhi 110025India Department of EC&IT MeityNew Delhi 110003India

The Internet of Things is a modern technology that is directed at easing human life by automating most of the things used in daily *** never-ending dependency on the network for communication is attracting adversaries to exploit the vulnerabilities of ***,this technology is facing some serious issues and challenges concerning security and *** issues and challenges are the real motivation behind considering this ***,this survey includes a discussion about security and privacy challenges as well as available solutions for IoT based wireless sensor *** systematic literature review(SLR)focuses particularly on a popular and applicable security approach known as Trust Management System(TMS).Firstly,all aspects of trust management,including trust indicators,trust properties,trust evaluation,trust building,trust models and the importance of those models for security and privacy,trust prediction methodologies,and ultimately trust-based attacks,are covered in this ***,trust management schemes are classified into four groups based on the methodology used for trust-based security solutions in the IoT:cryptography-based,computational and probabilistic-based,information theory-based,and ***,an understanding of the problems and difficulties with current methodologies is given,along with suggestions for further ***,the SLR is concluded by formulating the desirable characteristics of a trust management system in the IoT and proposing a trust model suitable for IoT networks.

关键词： Trust Trust management approaches IoT Security Privacy Reliability Attacks Trust attributes Systematic literature review Cybersecurity

Characteristics of lateral vehicular interactions in heterogeneous traffic with weak lane discipline

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Journal of Modern Transportation 2017年第2期25卷 74-89页

作者： Anuj Kishor Budhkar akhilesh kumar Maurya Department of Civil Engineering Indian Institute of Technology Guwahati Guwahati Assam 781039 India

Heterogeneous traffic conditions prevail in developing countries. Vehicles maintain weak lane discipline which increases lateral interactions of vehicles significantly. It is necessary to study these interactions in the form of maintained lateral gaps for modeling this traffic scenario. This paper aims at determining lateral clearances maintained by different vehicle types while moving in a heterogeneous traffic stream during overtaking. These data were collected using an instrumented vehicle which runs as a part of the stream. Variation of obtained clearance with average speed of interacting vehicles is studied and modeled. Different instrumented vehicles of various types are developed using （1） ultrasonic sensors fixed on both sides of vehicle, which provide inter-vehicular lateral distance and relative speed; and （2） GPS device with cameras, which provides vehicle type and speed of interacting vehicles. They are driven on different roads in six cities of India, to measure lateral gaps maintained with different interacting vehicles at different speeds. Relationships between lateral gaps and speed are modeled as regression lines with positive slopes and beta-distributed residuals. Nature of these graphs （i.e., slopes, intercepts, residuals） are also evaluated and compared for different interacting vehicle-type pairs. It is observed that similar vehicle pairs maintain less lateral clearance than dissimilar vehicle pairs. If a vehicle interacts with two vehicles （one on each side） simultaneously, lateral clearance is reduced and safety of the vehicles is compromised. The obtained relationships can be used for simulating lateral clearance maintaining behavior of vehicles in heterogeneous traffic.

关键词： Ultrasonic sensors - Heterogeneous traffic Lateral gaps Lateral vehicular interactions Weak lane discipline

An integrated fuzzy production inventory model for manufacturer–retailer coordination under simple carbon tax system

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Journal of Management Analytics 2023年第1期10卷 38-88页

作者： G.Durga Bhavani G.S.Mahapatra akhilesh kumar Department of Mathematics National Institute of Technology PuducherryKaraikalIndia Department of Mathematics Arignar Anna Government Arts and Science CollegeKaraikalIndia

This paper develops twin models towards integrated production inventory planning for manufacturer–retailer ecosystem in a sustainable supply chain ***-making models are developed in fuzzy environment and under purview of carbon taxation *** conception of Fermatean fuzzy numbers is introduced for handling parameters *** first model addresses planning problem without considering green investments,whereas the second one additionally identifies optimal green investments for each player of *** are formulated as nonlinear optimization problems with objective of maximizing *** of results from both models enables decision-makers to figure out the profitability of green investment *** instance with data from the existing literature is solved using Mathematica *** results for studied case report profitability of green investments for supply chain partners and significant reduction in carbon emissions as *** analysis demonstrates stability of the proposed *** models equip small-scale retailer-manufacture tie-ups prevalent in developing economies for discussed decisions.

关键词： sustainable supply chain carbon emission reduction production and inventory systems green investments organic ingredients Fermatean fuzzy numbers

Load shedding scheme for the two-area system with linear quadratic regulator

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Frontiers in Energy 2013年第1期7卷 90-102页

作者： D. tyagi Ashwani kumar Saurabh CHANANA Department of Electrical Engineering National Institute of Technology Kurukshetra 136119 India

The power system is prone to many emergency conditions which may lead to emergency state of operation with decay in the system frequency. The dramatic change in the frequency can result in cascaded failure of the system. In order to avoid power system collapse, load shedding （LS） schemes are adopted with the optimal amount of load shed. This paper proposed a methodology in a two-area thermal-thermal system for finding the required amount of load to be shed for setting the frequency of the system within minimum allowable limits. The LS steps have been obtained based on the rate of change of frequency with the increase in load in steps. A systematic study has been conducted for three scenarios： the scheme with a conventional integral controller; the scheme with a linear quadratic regulator （LQR）; and the scheme with an LQR and superconducting magnetic energy storage devices （SMES）. A comparison of the results has been presented on the two-area system.

关键词： critical load frequency response load shed- ding (LS) multi-area system rate of change of frequency linear quadratic regulator (LQR) superconducting magnetic energy storage devices (SMES)