Options
S M Shiva Nagendra
Loading...
Preferred name
S M Shiva Nagendra
Official Name
S M Shiva Nagendra
Alternative Name
Nagendra, Shiva M.
Nagendra, S.
Nagendra, S. M.Shiva
Nagendra, Shiva
Shiva Nagendra, S. M.
Shiva Nagendra, Saragur M.
Nagendra, Saragur Madanayak Shiva
Nagendra, Shiva Nagendra M.
Main Affiliation
Email
ORCID
Scopus Author ID
Researcher ID
Google Scholar ID
107 results
Now showing 1 - 10 of 107
- PublicationOzone pollution in Chinese cities: Assessment of seasonal variation, health effects and economic burden(01-04-2019)
;Maji, Kamal Jyoti ;Ye, Wei Feng ;Arora, MohitThe ground-level ozone (O3) concentration in the urban regions of China has become an increasingly noticeable environmental problem in recent years. Many epidemiological studies have reported the association between O3 pollution and mortality, only a few studies have focused on the O3-related mortality and corresponding economic effects at the Chinese city and province level. This study reports the seasonal variation of ground-level O3 in 338 cities of China during the year 2016 and evaluates its effect on premature mortality and economic loss. It further illustrates the differences in cause-specific mortality outcomes of the log-linear and linear model, two of the prominently used methods for estimating health effects. In 2016, the annual average daily maximum 8-h O3 concentration in China ranged between 74 and 201 μg/m3 (138 ± 24.7 μg/m3). 30% of the total population was exposed to >160 μg/m3 O3 concentration (Chinese national ambient air quality standard) and about 67.2% urban population lived in exposure above the WHO recommended O3 concentrations (100 μg/m3). The estimated national O3-attributable mortality was 74.2 × 103 (95% CI: 16.7×103–127×103) in the log-linear model, whereas, the total O3-related mortality using the linear model was 69.6 × 103 (95% CI: 16.2 × 103–115 × 103). The exposure to O3 caused a nationwide economic loss of about 7.6 billion US$ (range: 1.7–12.9) in 2016. This study uniquely provides most comprehensive coverage of the Chinese cities for O3 associated mortality utilizing ground level measurement data for 2016 and presents a measurable assessment to the policymakers of China for streamlining their efforts on air quality improvement and O3 containment. - PublicationSupercontinuum Laser Based Photoacoustic Approach for Acetylene Gas Sensing(02-07-2018)
;Selvaraj, Ramya; A broadband photoacoustic gas sensor with solid etalon using supercontinuum laser for acetylene monitoring was characterized. The acetylene concentration was determined to be 330 pptv at a data acquisition time of 10 ms. - PublicationA system based approach to develop hybrid model predicting extreme urban NOx and PM2.5 concentrations(01-10-2017)
;Gulia, Sunil; Khare, MukeshOne of the major drawbacks of conventional air quality models is their inability in accurately predicting extreme air pollutant concentrations. Hybrid modelling is one of the techniques that estimates/predicts the ‘entire range’ of the distribution of pollutant concentrations by combining the deterministic based models (capable in predicting average range) with suitable statistical (probability) distribution models (capable in predicting extreme range). This research paper describes system based approach in developing hybrid model to predict hourly averages as well as extreme percentile ranges of NOx and PM2.5 concentrations at two urban locations having complex traffic heterogeneity, highly variable tropical meteorology and different geographical characteristics. At one of the selected locations i.e. Delhi megacity, during winters, hybridization of AERMOD and Lognormal predicts NOx and PM2.5 concentrations satisfactorily with index of agreement ‘d’ values of 0.98–0.99, respectively; however, during summers, AERMOD-Log-logistic and AERMOD-Lognormal are best predicting NOx and PM2.5 concentrations with d values of 0.98–0.96, respectively. In another, i.e., Chennai, a coastal megacity, AERMOD-Lognormal predicts PM2.5 concentrations satisfactorily with d values of 0.98 and 0.99 during winter and summer seasons, respectively. Further, hybrid model has also been used to evaluate regulatory compliance. - PublicationCharacteristics of criteria air pollutants in Manali industrial area, Tamilnadu(01-01-2015)
;Panda, SmaranikaThe criteria air pollutants (NO, NO2, SO2, PM10 monitored at Manali industrial area during 2011 were characterized. The total SOx, NOx, and SPM load in the Manali industrial area were 22.8, 7.88, and 7.11 ton/day. The average SO2 and PM10 concentrations in winter were 31.13 and 24.87% higher than in summer. NO concentrations were high during the early mornings due to the presence of stagnant atmospheric condition. NO2 concentrations showed two peaks corresponding to the morning and the evening peak hour traffic flows. This is an abstract of a paper presented at the 108th AWMA Annual Conference and Exhibition (Raleigh, NC 6/22-25/2015). - PublicationEvaluation of comfort perception of passengers in urban underground metro stations(01-06-2022)
;Passi, Amit; Indoor thermal comfort levels in underground metro platforms and trains in Chennai metropolitan city are assessed in the present research study to determine the comfort perception of passengers. The field measurements were conducted in 7 underground metro stations during summer (Mar-Jun 2019) and winter seasons (Dec 2019 - Feb 2020). The thermal comfort of metro passengers is investigated through environmental parameters and a subjective survey. Results indicated that the percentage of unacceptability in metro platforms is in the range of 36.7–98.8%, while inside the metro trains it is less than 12%. This indicates the efficiency of the in-train air-conditioning systems compared to metro platforms. Good agreement is found between the findings of the thermal comfort investigation and the comfort perception of passengers. A linear and very strong positive correlation is found between operative temperature and the percentage of passengers dissatisfied. No relation is found between the metro stations' indoor and outdoor thermal conditions. Thus, it is inferred that internal factors such as the functioning of stations, operation of metro trains, and high density of passengers contribute significantly to indoor heat generation. During both seasons, the thermal conditions in all metro stations surpassed the ASHRAE-55 and ISO7730 guidelines. Stations with low passenger traffic are maintained with high operative temperatures to save energy costs. Based on the prevailing thermal conditions and ASHRAE recommendations of operative temperature, a Predicted Percentage of Dissatisfied (PPD) value of up to 40% could be deemed a thermal comfort metric that can be acceptable in underground metro stations. - PublicationParticulate matter exposure analysis in 12 critical urban zones of Chennai, India(01-09-2022)
;Sneha, M. ;Alshetty, Dheeraj ;Ramsundram, N.This research paper examines the exposure to particulate matter (PM) and its deposition on the human respiratory tract (HRT) in 12 critical urban zones — institutional zone, commercial zone, construction zone, hospital zone, landfill zone, industrial zone, residential zone, high-traffic zone, main roads, medium-traffic zone secondary roads, low-traffic zone, coastal zone, and environmentally sensitive zone. This study measured the size-segregated PM concentrations using a Grimm aerosol spectrometer. The multiple-path particle dosimetry model assesses particles’ total and regional deposition mass rates for different urban zones. A stochastic model of the 60th percentile is used to illustrate the deposition of PM in the human lung. The deposition rate of PM in the HRT is examined for the different urban zones from different emission sources. The analysis shows that the PM concentration in zone V (dumpsite zone) is at an elevated level (i.e., PM10 = 570.4 µg/m3, PM2.5 = 128.3 µg/m3, and PM1 = 28.1 µg/m3) and lowest at zone XII (eco-sensitive zone) (i.e., PM10 = 25.1 µg/m3, PM2.5 = 1 6.9 µg/m3, and PM1 = 14.8 µg/m3). Further, dumpsite, commercial, and eco-sensitive zones are identified to be critical zones that influence higher deposition in the tracheobronchial and pulmonary regions. The investigation concludes that local turbulence and emission source significantly impacts air quality and deposition of PM at HRT. In addition, as the PM diameter decreases, the acidity of PM increases, and it can penetrate deep into the lower airways. Since this can have profound consequences, it is imperative to better understand the deposition of PM across various urban zones. - PublicationModal analysis of real-time, real world vehicular exhaust emissions under heterogeneous traffic conditions(01-07-2017)
;Jaikumar, Rohit; Sivanandan, R.This study presents the characteristics of real world, real time, on-road vehicular exhaust emission namely, carbon monoxide (CO), nitric oxide (NO), hydrocarbons (HC), and carbon dioxide (CO2) emitted under heterogeneous traffic conditions. Field experiments were performed on major category of vehicles in developing countries, i.e. two-wheelers, auto-rickshaws, cars and buses. The on-board monitoring was carried out on different corridors with varying road geometry. Results revealed that the driving cycle was dependent on the road geometry, with two lane mixed flow corridor having lot of short term events compared to that of arterial road. Vehicular emissions during idling and cruising were generally low compared to emissions during acceleration. It was also found that emissions were significantly dependent on short term events such as rapid acceleration and braking during a trip. Also, the standard emission models like COPERT and CMEM under predicted the real world emissions by 30–200% depending upon different driving modes. The on-road emissions measurements were able to capture the emission characteristics during the micro events of real world driving scenarios which were not represented by standard vehicle emission measured at laboratory conditions. - PublicationSource characterization of PM 10 and PM 2.5 mass using a chemical mass balance model at urban roadside(01-09-2012)
;Srimuruganandam, B.The 24-h average ambient particulate matter (PM 10 and PM 2.5) concentrations are sampled concurrently during November 2008-April 2009 at a busy roadside in Chennai City, India. The elemental (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn) and ionic (Na +, NH 4+, K +, Ca 2+, Mg 2+, F -, Cl -, NO 2-, NO 3- and SO 42-) composition of PM 10 and PM 2.5 are determined using an inductively coupled plasma-optical emission spectrometer (ICP-OES) and an ion chromatograph (IC), respectively. The emission inventory at the study area is also carried out to identify the likely PM emission sources. The U.S. EPA's-CMB (chemical mass balance) version 8.2 is applied to identify the source contribution of ambient PM 10 and PM 2.5 concentrations at the study area. Results indicated that diesel exhausts (43-52% in PM 10 and 44-65% in PM 2.5) and gasoline exhausts (6-16% in PM 10 and 3-8% in PM 2.5) are found to be the major source contributors at the study site followed by the paved road dusts (PM 10=PM 2.5=0.-2.3%), brake lining dusts (0.1% in PM 10 and 0.2% in PM 2.5), brake pad wear dusts (0.1% in PM 10 and 0.01% in PM 2.5), marine aerosols (PM 10=PM 2.5=0.1%) and cooking (~0.8% in PM 10 and ~1.5% in PM 2.5). © 2012 Elsevier B.V. - PublicationPerformance evaluation of the adms-urban model in predicting PM10 concentrations at the roadside in Chennai, India and Newcastle, UK(01-12-2011)
; ;Khare, M. ;Vijay, P.Gulia, S.Recent economic development in many Asian and European countries has shown an increase in vehicle kilometre travel (VKT) in many cities, which has resulted in an increase in the vehicular pollution levels. In particular, particulate matter (PM) concentrations emitted from vehicles are at alarming levels in most of the cities of the world. Therefore, there is growing interest in the formulation of local level air quality management system to tackle vehicular emissions. Many mathematical models have been widely used as tools in urban air quality management. In the present paper, an attempt has been made to evaluate the performance of the ADMS Urban model in predicting roadside PM concentrations at two cities namely Chennai, India and Newcastle, UK during critical winter period of the year 2009. The statistical parameters such as Index of Agreement (IA), Fractional Bias (FB), Normalized Mean Square Error (NMSE), Geometric Mean Bias (MG) and Geometric Mean Variance (VG) have been used to evaluate the ADMS model performance. Results indicated that the roadside PM concentrations predicted by the ADMS model are reasonably accurate for Newcastle than at the roadside in Chennai. © 2011 WIT Press. - Publication