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Rare earth metal doped CeO_2-based catalytic materials for diesel soot oxidation at lower temperatures

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Journal of Rare Earths 2015年第11期33卷 1162-1169页

作者： A.rangaswamy Putla Sudarsanam Benjaram M.Reddy Inorganic and Physical Chemistry Division CSIR-Indian Institute of Chemical Technology Centre for Advanced Materials and Industrial Chemistry (CAMIC) School of Applied Sciences RMIT University

In this work, the influence of trivalent rare-earth dopants（Sm and La） on the structure-activity properties of CeO2 was thoroughly studied for diesel soot oxidation. For this, an optimized 40% of Sm and La was incorporated into the CeO2 using a facile coprecipitation method from ultra-high dilute aqueous solutions. A systematic physicochemical characterization was carried out using X-ray diffraction（XRD）, transmission electron microscopy（TEM）, Brumauer-Emmett-teller method（BET） surface area, X-ray photoelectron spectroscopy（XPS）, Raman, and H2-temperature programmed reduction（TPR） techniques. The soot oxidation efficiency of the catalysts was investigated using a thermogravimetric method. The XRD results suggested the formation of nanocrystalline single phase CeO2-Sm2O3 and CeO2-La2O3 solid solutions. The Sm- and La-doped CeO2 materials exhibited smaller crystallite size and higher BET surface area compared with the pure CeO2. Owing to the difference in the oxidation states of the dopants（Sm3＋ and La3＋） and the Ce4＋, a number of oxygen vacancies were generated in CeO2-Sm2O3 and CeO2-La2O3 samples. The H2-TPR studies evidenced the improved reducible nature of the CeO2-Sm2O3 and CeO2-La2O3 samples compared with the CeO2. It was found that the addition of Sm and La to the CeO2 outstandingly enhanced its catalytic efficiency for the oxidation of diesel soot. The observed 50% soot conversion temperatures for the CeO2-Sm2O3, CeO2-La2O3 and CeO2 were ~790, 843 and 864 K（loose contact）, respectively, and similar activity order was also found under the tight contact condition. The high soot oxidation efficacy of the CeO2-Sm2O3 sample was attributed to numerous catalytically favourable properties, like smaller crystallite size, larger surface area, abundant oxygen vacancies, and superior reducible nature.

关键词： rare earths cerium oxide solid solutions oxygen vacancies soot oxidation

Bridging electrical power and entropy of ONU in EPON

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Optoelectronics Letters 2021年第2期17卷 102-106页

作者： Bhargav Ram Rayapati Nakkeeran rangaswamy Department of Electronics Engineering School of Engineering and TechnologyPondicherry UniversityPondicherry 605014India

This letter deliberates bridging of overall electricity power requirements of the optical network unit(ONU) with the entropy noted through the ONU state transition models considered in ethernet passive optical network(EPON). The entropy depends on the steady state and transition probabilities of data. On the other hand, the power requirements(consumption) of ONUs depend on the steady sate probability of ONUs. The potential relation derived between the entropy and electrical power reveals that they related exponentially but for their logarithmic reliance. Also, the relation is validated through the numerical simulation. The deduced relation has its importance to understand the nuances of one entity given the other.

关键词： power ONU network

Seepage behavior of soil mixed with randomly distributed recycled plastic materials

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Water Science and Engineering 2022年第3期15卷 257-264页

作者： V.P.Devipriya S.Chandrakaran K.rangaswamy Department of Civil Engineering National Institute of Technology CalicutCalicut 673601India

Seepage through embankment fill materials is crucial issue in the construction of embankments for irrigation and drainage *** ground improvement methods should be used to improve the strength and stability characteristics of soil used as fill *** of waste plastic materials to enhance the engineering properties of soil is a sustainable ***,the use of raw products directly from plastic recycling units in the form of flakes and pellets as soil additives has the potential to further enhance the economic benefits of this *** study randomly mixed plastic materials with soil for use in the construction of earth embankments,such as river levees,dykes,and canal diversion structures,and evaluated the effectiveness of these materials in reducing seepage failures in hydraulic *** achieve these goals,this study collected high-density polyethylene(HDPE)plastic from plastic recycling units and used soil mixed with HDPE plastic in the form of flakes and pellets in different contents as embankment fill materials,then evaluated how these materials affected the piping *** experiments were conducted to determine the seepage velocity and critical hydraulic gradient of soil mixed with plastics in various contents and to compare the values with those of plain *** results showed that random distribution of waste plastics in the form of flakes and pellets in soil is an effective method for improving the piping resistance of soil.

关键词： Earth embankments Seepage Recycled plastics Critical hydraulic gradient Piping resistance

User preference-based intelligent road route recommendation using SARSA and dynamic programming

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Journal of Control and Decision 2023年第3期10卷 443-453页

作者： Roopa Ravish Shanta rangaswamy Arpitha V Vasuprada U PES University BengaluruIndia Rashtreeya Vidyalaya College of Engineering BengaluruIndia

Traffic congestion is one of the main challenges in transportation engineering. It directly impactsthe economy by increasing travel time and affecting the environment by excessive fuel consumptionand emission. Road route recommendation to overcome the congestion by alternativeroute suggestions has gained high importance. The existing route recommendation systems areproposed using the reinforcement learning algorithm (Q-learning). The techniques suggestedin this paper are state-action-reward-state-action (SARSA) algorithm and dynamic programming(DP) to guide the commuters to reach the destination with an optimal solution. The algorithmconsiders travel time, cost, flexibility, and traffic intensity as the user preference attributes torecommend an optimal route. The recommended system is implemented by building a roadnetwork graph. We assign values to each user preference attribute along the edges, which cantake high(1) or low(0) values. By considering these values, the system recommends the *** proposed system performance is evaluated based on computation time, cumulative reward,and accuracy. The results show that DP outperforms the SARSA algorithm.

关键词： Intelligent transport system machine learning techniques in ITS SARSA algorithm dynamic programming route guidance system travel time prediction traveller information system

Quieting the neonatal intensive care unit:A quality improvement initiative

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World Journal of Clinical Pediatrics 2024年第3期13卷 53-60页

作者： Darshan Rajatadri rangaswamy Niranjan Kamble Amulya Veeramachaneni Department of Pediatrics Subbaiah Institute of Medical SciencesShimoga 577222KarnatakaIndia

BACKGROUND The neonatal intensive care unit(NICU)is vital for preterm infants but is often plagued by harmful noise *** noise,ranging from medical equipment to conversations,poses significant health risks,including hearing impairment and neurodevelopmental *** American Academy of Pediatrics recommends strict sound limits to safeguard neonatal *** such as education,environmental modifications,and quiet hours have shown to reduce noise ***,up to 60%of the noises remain *** noise exposure exacerbates physiological disturbances,impacting vital functions and long-term neurological *** noise reduction in the NICU is crucial for promoting optimal neonatal *** To measure the sound levels in a NICU and reduce ambient sound levels by at least 10%from *** A quasi-experimental quality improvement project was conducted over 4 mo in a 20-bed level 3 NICU in a tertiary care medical *** noise levels were recorded continuously using a sound level *** interventions included targeted education,environmental modifications,and organizational changes,and were implemented through three rapid Plan-Do-Study-Act(PDSA)*** feedback and monitoring were conducted,and statistical process control charts were used for *** mean noise values were compared using the paired *** The baseline mean ambient noise level in the NICU was 67.8 dB,which decreased to 50.5 dB after the first cycle,and further decreased to 47.4 dB and 51.2 dB after subsequent *** reduction in noise levels was 21%during the day and 28%PDSA cycle(mean difference of−17.3 dB,P<0.01).Peak noise levels decreased from 110 dB to 88.24 dB after the *** A multifaceted intervention strategy reduced noise in the NICU by 25%over 4 *** success of this initiative emphasizes the significance of comprehensive interventions for noise reduction.

关键词： Quality improvement Noise pollution Preterm care Sound measurement Plan-Do-Study-Act

Heuristic polling sequence to enhance sleep count of EPON

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Frontiers of Optoelectronics 2019年第4期12卷 422-432页

作者： Bhargav Ram RAYAPATI Nakkeeran rangaswamy Department of Electronics Engineering Pondicherry UniversityPondicherry 605014India

Next-generation passive optical networks(PONs)demand power conservation to create a green environment.A reduction in power consumption of the traditional Ethernet passive optical network(EPON)can be achieved by increasing the sleep count in optical network units(ONUs).In this paper,this is accomplished by introducing a first-in-last-out(FILO)polling sequence in the place of a fixed polling sequence to increase the number of ONUs entering sleep mode(sleep count).In a fixed polling sequence,the optical line terminal(OLT)allocates idle time to the ONUs based on the overall load of the *** leads to a situation that whenever the idle time does not meet the wakeup time threshold of sleep mode,the ONUs are put into doze/active mode,which consumes more *** the FILO polling sequence,the first polled ONU in the current cycle is made to be polled last in the following *** continues in this way,and by this rearrangement,the idle time of delayed poll ONUs increases;hence,it helps to reduce the power ***,a modified load adaptive sequence arrangement(MLASA)method is suggested,where the ONUs are categorized into doze ONUs and sleep ONUs.A numerical simulation of the FILO polling sequence with a vertical cavity surface emitting laser(VCSEL)ONU shows a maximum reduction in power consumption of 15.5 W and a 20%improvement in energy savings compared with the traditional fixed polling *** MLASA method results in better power consumption with minimum delay than that of the proposed FILO and existing LASA methods.

关键词： Ethernet passive optical network(EPON) optical network unit(ONU) polling sequence power conservation

Predicting suitable habitat of an invasive weed Parthenium hysterophorus under future climate scenarios in Chitwan Annapurna Landscape,Nepal

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Journal of Mountain Science 2019年第10期16卷 2243-2256页

作者： MAHARJAN Seerjana SHRESTHA Bharat Babu JOSHI Mohan Dev DEVKOTA Anjana MUNIAPPAN rangaswamy ADIGA Abhijin JHA Pramod Kumar Central Department of Botany Tribhuvan UniversityKirtipurKathmanduNepal Department of Plant Resources ThapathaliKathmanduNepal IPM Innovation Lab Virginia Tech526Prices Fork RoadBlacksburgVA24061USA Biocomplexity Institute and Initiative University of VirginiaUSA

Chitwan-Annapuma Landscape(CHAL)in central Nepal is known for its rich biodiversity and the landscape is expected to provide corridors for species range shift in response to climate *** assessments have identified biological invasions and other anthropogenic activities as major threats to the biodiversity in the *** of the rapidly spreading Invasive Alien Plant species(IAPs)in the CHAL is Parthenium hysterophorus L.,a neotropical invasive weed of global *** study aimed to investigate the current and future projected suitable habitat of *** in the CHAL using MaxEnt modelling in three'Representative Concentration Pathways'(RCPs 2.6,4.5 and 8.5)corresponding to different greenhouse gases emissiontrajectories for the year 2050 and 2070.A total of 288species occurrence points,six bioclimatic variablesmean diurnal range,isothermality,annual precipitation,precipitation of driest month,precipitation seasonality,precipitation of driest quarter and two topographic variables(aspect and slope)were selected for MaxEnt *** range shift in terms of increase or decline in the suitable habitat areas under the projected scenarios were *** and annual precipitation were the most important variables that explained the current distribution of *** percent of the total area of CHAL was predicted to be suitable habitat for the growth of *** in the current climatic *** gain in the suitable habitat of this noxious weed was found under RCP 4.5 scenario in 2050 and *** there will be a loss in thesuitable habitat under RCP 8.5 scenario in 2050 *** of four physiographic regions present in CHAL,three regions-Siwalik,Middle Mountain and High Mountain have suitable habitat for *** under current climatic *** mountainous region is likely to be affected more than the Siwalik region by further spread of *** in the future under low(R

关键词： Parthenium weed Ecological Niche Model MaxEnt Invasive species Habitat suitability

Assessment of groundwater quality in the flood plains of upper Palar River, India

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Chinese Journal Of Geochemistry 2012年第1期31卷 15-23页

作者： Rutharvel Murthy Kuppuraj Dhanakumar Selvaraj Solaraj Govindaraj Mohanraj rangaswamy Jawahar Raj Narayanasamy Kumaraswamy Kuppanagounder Department of Geography School of GeosciencesBharathidasan UniversityTiruchirappalli 620024India Department of Environmental Management Bharathidasan UniversityTiruchirappalli 620024India Department of Geology National CollegeTiruchirappalli 620001India

Groundwater is generally presumed to be good for human consumption and is used as a main source of drinking water. Although there are numerous reasons for groundwater pollution, anthropogenic sources are consid-ered as the prime ones. In this study, twenty-two groundwater samples were collected from the flood plains of upper Palar River during the pre- and post-monsoon seasons to assess the extent of pollution and effects on human health. Physico-chemical characteristics of groundwater were analyzed and compared with those of drinking water standards recommended by the World Health Organization (WHO) and the Bureau of Indian Standards (BIS). The Piper's tri-linear diagram shows the nature of alkali earth with the high contents of alkalies and prevailing sulphate in the pre-sent samples. The univariate statistics and correlation analysis were performed to find out the relationships between the variables. The tannery effluents, solid wastes and sewage were suspected to be the predominant sources of pollu-tion in the area.

关键词：地下水污染冲积平原水质评价印度饮用水标准上游物理化学特性世界卫生组织

PC Based Optical Salinity Sensor for Different Temperatures

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Photonic Sensors 2012年第2期2卷 187-192页

作者： Savarimuthu ROBINSON rangaswamy NAKKEERAN Department of Electronics and Communication Engineering Pondicherry Engineering College Puducherry-605 014India

Abstract： The homogeneous, intensity modulated salinity sensor using the photonic crystal ring resonator （PCRR） is proposed and designed for monitoring the salinity of the seawater from 0% to 100% （0 g/L to 100 g/L） at 25℃. The concentration of the salinity in the seawater changes the refractive index of the seawater. The change in the refractive index of the seawater brings the change in the output signal intensity of the sensor as the output power and mapping the salinity level, the seawater flows inside the sensor. By detecting the salinity can be evaluated. The proposed sensor is composed of periodic Si rods embedded in an air host with a circular PCRR placed between the inline quasi waveguides. Approximately, 2.69% of output power reduction is observed for every 5% （5 g/L） increase in the salinity as the seawater has a unique refractive index for each salt level. With this underlying principle, the performance of the sensor is analyzed for different temperatures.

关键词： Optical sensor salinity measurement photonic crystal refractive index