16 results on '"Kumar, Mayank"'
Search Results
2. Description of a New Species of Panotrogus Reitter, 1902 (Coleoptera: Scarabaeidae: Melolonthinae) from Uttarakhand, India.
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KUMAR, Mayank, PANDEY, Ajay Kumar, and KEITH, Denis
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SCARABAEIDAE , *BEETLES , *SPECIES , *INSECT traps , *SUBSPECIES - Abstract
Panotrogus Reitter, 1902 is genus of the Melolonthinae tribe Rhizotrogini (Scarabaeidae) that currently contains 21 species and 2 subspecies, of which 14 species have been recorded from Himalaya region of India. A new species Panotrogus jagbiri Kumar, Pandey & Keith, sp. nov. is described from Uttarakhand, India and illustrated. A key to Indian Panotrogus species has been prepared. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. First Record of Three Species of Genera Panotrogus Reitter, 1902 and Pseudopanotrogus Petrovitz, 1969 (Coleoptera; Scarabaeidae; Rhizotrogini) from India.
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KUMAR, Mayank, PANDEY, Ajay Kumar, and KEITH, Denis
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SCARABAEIDAE , *BEETLES , *INSECT traps , *MALE reproductive organs , *SPECIES ,BEETLE anatomy - Abstract
Tribe Rhizotrogini is a tribe of June beetle containing many species of agronomic importance in India. It holds major genera like Brahmina (Blanchard 1851), Eotrichia (Medvedev 1951), Holotrichia (Hope 1837) or Sophrops (Fairmaire 1887) in India. A survey based on light trap collection was conducted in various locations of Uttarakhand to check for the presence of the species. During surveys in the years 2021 and 2022, various chafer beetles were collected to observe the distribution pattern and their hosts. Among these various species, three beetle species are here reported for the first time i.e. Panotrogus expansus Keith, 2003, Panotrogus pakistanus Keith, 2002 and Pseudopanotrogus extrarius Keith, 2005 from Uttarakhand, India. This also represents their first record for India. Their habitus and male genitalia are provided herein to aid in identification. A complete list of species from the Himalayan region is also provided. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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4. Comparative Analysis of Red Cell Parameters of First-time and Repeat Blood Donors: A Descriptive Study.
- Author
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SINGH, RANVIJAY, KUMAR, MAYANK, SINGH, DINESH KUMAR, KHARBANDA, PARAS, and VERMA, SATYAJEET
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DIRECTED blood donations , *ERYTHROCYTES , *IRON deficiency anemia , *CELL analysis , *BLOOD donors , *BLOOD cell count - Abstract
Introduction: Blood transfusion services form an essential component of any healthcare system and it is imperative to provide adequate and safe blood for management of patients. Voluntary blood donors form the backbone of this service. However, regular donation by such voluntary donors may cause significant depletion of iron stores in the body. This has the potential to adversely affect the donor's health, and also to lower the quality of blood being collected subsequently. The temporary deferral of such donors also causes reluctance to return for future blood donations, leading to decrease in size of the donor pool. The prompt detection of subclinical iron deficiency in voluntary blood donors is the need of the hour. Aim: To compare and analyse the difference in red cell parameters of first-time and repeat blood donors. Materials and Methods: A descriptive study was conducted by the Department of Blood Bank and Pathology at Rajarshi Dashrath Autonomous State Medical College, Ayodhya, Uttar Pradesh, India, from July 2021 to December 2022. After prospective donors were assessed for suitability of blood donation, written informed consent was obtained, and 5 mL venous blood was collected into an Ethylenediaminetetraacetic Acid (EDTA)- anticoagulated vial via the antecubital fossa. Complete blood count was performed within one hour of collection using an automated haematology analyser. The parameters analysed in the study were Red Blood Cell (RBC) count, haemoglobin, Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH), Mean Corpuscular Haemoglobin Concentration (MCHC), and Red cell Distribution Width (RDW). The generated data was compiled and statistical analysis, with Kruskal-Wallis test (at a p-value of 0.05) and post-hoc Dunn test was performed to determine the significant differences, if any. Results: The study included 455 participants, out of which 210 were repeat blood donors. The significant differences for MCV, MCH and RDW between groups defined by number of donations (p-value <0.001) was observed. The difference was most significant between the donors having five or more donations compared to donors having no previous donations. No significant differences were observed for other parameters, with p-values for RBC count, haemoglobin, and MCHC being 0.3, 0.07, and 0.09, respectively. Conclusion: Repeat blood donors having low MCV and MCH along with high RDW, with haemoglobin values within normal range, are most susceptible to having subclinical iron deficiency, which needs to be identified and managed pre-emptively, before development of Iron Deficiency Anaemia (IDA). This is necessary in order to retain regular and repeat voluntary blood donors, and also to ensure adequate quality of collected blood. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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5. Locating resistance to healthcare information technology: A Bourdieusian analysis of doctors' symbolic capital conservation.
- Author
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Kumar, Mayank, Singh, Jang Bahadur, Chandwani, Rajesh, and Gupta, Agam
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SYMBOLIC capital ,CAPITAL cities ,SOCIAL status ,PHYSICIANS ,INFORMATION technology ,CAPITAL structure - Abstract
This research examines the socially significant issue of doctors' resistance to healthcare information technology (HIT) from the radical power perspective. It adopts Bourdieu's social practice theory to examine the interaction of HIT with the reproduction of doctors' historically rooted social standing through the doctor‐patient‐interaction (D‐P‐I) practice. Findings from our ethnographic enquiry at a large corporate healthcare organisation in India link doctors' historically rooted social standing to the symbolic recognition of their embodied emotional capital existing in tandem with their habitus. The symbolic recognition of emotional capital provided a better valorisation of clinical capital and allowed the accumulation of other forms of capital—institutionalised capital, social capital and economic capital—that formed doctors' capital structure and contributed to their social status. Doctors produced emotional capital by putting their habitus into practice and, in the process, reproduced its symbolic status and their social status linked to it. HIT challenged doctors to put their habitus into practice, thereby creating a perception of threat to emotional capital. Doctors' HIT resistance was a conservation strategy to reproduce their historically rooted higher social status. Findings from this study contribute to the literature on Power and IT resistance. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Anesthesia-related perioperative patient safety services in Indian public and private hospitals with or without teaching programs: A matched analysis of qualitative survey data.
- Author
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Karim, Habib Md Reazaul, Kumar, Mayank, and Sinha, Mamta
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PERIOPERATIVE care ,STATISTICS ,ANESTHESIA ,ACADEMIC medical centers ,MEDICAL care ,FISHER exact test ,COMPARATIVE studies ,PUBLIC hospitals ,DESCRIPTIVE statistics ,PROPRIETARY hospitals ,DATA analysis ,PATIENT safety ,SECONDARY analysis - Abstract
Introduction: The World Health Organization is emphasizing global patient safety for more than a decade. However, very less is known about the patient safety environment in the perioperative settings in developing countries. The present secondary analysis aimed to compare the anesthesia-related patient safety measures and services in Indian public versus private and teaching versus nonteaching hospitals. Materials and Methods: The present study is a post hoc, subgroup analysis of a previously conducted cross-sectional, questionnaire-based, online survey during February-May 2019. Responses from the postgraduate trainee and consultant/qualified practitioners were included. Data related to the practice pattern and availability of standard, advanced monitoring, and equipment were then categorized based on the hospital funding source and availability of teaching program; compared using the Fisher's exact test, and P < 0.05 was considered statistically significant. Results: Six hundred responses were included. The majority (60.7%) were from the private sector; 57.3% worked in teaching hospitals. Overall, anesthesia-related patient safety and equipment were deficient across the entire range of hospitals. However, there was no difference between matched public and private hospitals (P > 0.05 for most), except the anonymous incident reporting, which was significantly higher in the corporate teaching hospitals (P < 0.0001). Teaching hospitals had significantly better safety measures (P < 0.0001 for most parameters) than nonteaching hospitals. Conclusion: Public sector hospitals in India are not having significantly different anesthesia services related to patient safety monitoring and equipment than private sector hospitals. However, the safety measures are relatively low in many aspects across all sectors, which need attention. [ABSTRACT FROM AUTHOR]
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- 2022
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7. HOST PREFERENCE AND POPULATION DYNAMICS OF HOLOTRICHIA NAGPURENSIS KHAN AND GHAI.
- Author
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KUMAR, MAYANK and PANDEY, A. K.
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POPULATION dynamics ,NEEM ,HOST plants ,HUMIDITY ,TWO-way analysis of variance ,MULTIPLE comparisons (Statistics) - Abstract
Holotrichia nagpurensis Khan and Ghai is a major white grub species of subfamily Melolonthinae. Its wide host range has been reported from different parts of India. An experiment was carried out to find host preference and population dynamics at three locations of Pantnagar in Terai region of Udham Singh Nagar District during 2018-19. Beetles were recorded from six host plants among which neem Azadirachta indica, was the major one. The p-value of two-way ANOVA between populations of three locations (0.0006<0.001) and from six hosts (0.0002<0.001) showed that there exists significant difference in distribution and feeding preference of H. nagpurensis on host plants. Among the hosts, A. indica was found to be the most preferred with maximum adult density (419 adults) and average 46.55 beetles/ tree; and the multiple comparisons revealed a significant host preference. Correlation coefficients revealed that minimum relative humidity exhibits a negative relationship with beetle emergence. [ABSTRACT FROM AUTHOR]
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- 2022
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8. Inter-comparison of online and offline methods for measuring ambient heavy and trace elements and water-soluble inorganic ions (NO3-, SO42-, NH4+ and Cl-) in PM2.5 over a heavily polluted megacity, Delhi
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Bhowmik, Himadri Sekhar, Shukla, Ashutosh, Lalchandani, Vipul, Dave, Jay, Rastogi, Neeraj, Kumar, Mayank, Singh, Vikram, and Tripathi, Sachchida Nand
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HEAVY elements ,TRACE metals ,TRACE elements ,MEGALOPOLIS ,PLASMA spectroscopy ,MASS spectrometry ,HEAVY metals - Abstract
Characterizing the chemical composition of ambient particulate matter (PM) provides valuable information on the concentration of secondary species, toxic metals and assists in the validation of abatement techniques. The chemical components of PM can be measured by sampling on filters and analysing them in the laboratory or using real-time measurements of the species. It is important for the accuracy of the PM monitoring networks that measurements from the offline and online methods are comparable and biases are known. The concentrations of water-soluble inorganic ions (NO
3 - , SO4 2- , NH4 + and Cl- ) in PM2.5 measured from the 24 hrs filter samples using ion chromatography (IC) were compared with the online measurements of inorganics from aerosol mass spectrometer (AMS) with a frequency of 2 mins. Also, the concentrations of heavy and trace elements determined from the 24 hrs filter samples using inductively coupled plasma mass spectroscopy (ICP-MS) were compared with the online measurements of half-hourly heavy and trace metal's concentrations from Xact 625i ambient metal mass monitor. The comparison was performed over two seasons (summer and winter) characterized by their different metrological conditions at IITD and during winter at IITMD, two sites located in Delhi, NCR, India, one of the heavily polluted urban areas in the world. Collocated deployments of the instruments helped to quantify the differences between online and offline measurements and evaluate the possible reasons for positive and negative biases. The slopes for SO4 2- and NH4 + were closer to 1:1 line during winter and decreased during summer at both sites. The higher concentrations on the filters were due to the formation of particulate (NH4 )2 SO4 . Filter-based NO3 - measurements were lower than online NO3 - during summer at IITD and winter at IITMD due to the volatile nature of NO3 - from the filter substrate. Offline measured Cl- was consistently higher than AMS derived Cl- during summer and winter at both sites. Based on their comparability characteristics, elements were grouped under 3 categories. The online element data were highly correlated (R2 > 0.8) with the offline measurements for Al, K, Ca, Ti, Zn, Mn, Fe, Ba, and Pb during summer at IITD and winter at both the sites. The higher correlation coefficient demonstrated the precision of the measurements of these elements by both Xact 625i and ICP-MS. Some of these elements showed higher Xact 625i elemental concentrations than ICP-MS measurements by an average of 10-40 % depending on the season and site. The reasons for the differences in the concentration of the elements could be the distance between two inlets for the two methods, line interference between two elements in Xact measurements, sampling strategy, variable concentrations of elements in blank filters and digestion protocol for ICP measurements. [ABSTRACT FROM AUTHOR]- Published
- 2021
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9. An observation from an online survey: is fresh gas flow used for sevoflurane and desflurane different from isoflurane based anesthesia?
- Author
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Reazaul Karim, Habib, Sinha, Mamta, Kumar, Mayank, Khetrapal, Monica, and Dubey, Rashmi
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GAS flow ,COMPUTER surveys ,ANESTHETICS ,ANESTHESIA ,ANESTHESIOLOGISTS - Abstract
Minimal uses of fresh gas flow (FGF) during volatile inhalational agents based anesthesia are gaining popularity for many reasons. However, the practice pattern is not uniform. Even the same anesthesiologist uses different FGF for different agents. The present study was aimed to evaluate the variation in the practice pattern of FGF used in context to volatile agents used. With departmental approval, the present study was conducted by reviewing the data of a previously conducted cross-sectional survey. The survey was conducted from January 2018 to May 2018 using SurveyMonkey
; . Anesthesiologists working in different organizations across India were approached through e-mail and WhatsApp and anonymous responses were collected. The responses which contained FGF data for isoflurane and for at least one of either sevoflurane and/or desflurane were included. A total of 236 eligible responses were analyzed. The FGFs used by different anesthesiologists were very much inconsistent; only 5.1% used FGF < 600 mL/min and 19.1% used 600-1000 mL/min consistently for all three agents. There was a significant variation of FGF used for sevoflurane and desflurane as compared to isoflurane. Use of FGF of < 1000 mL/min was significantly higher for the desflurane as compared to both isoflurane and sevoflurane. The uses of lower FGF greatly vary both at intrapersonal as well as interpersonal level. The possibility of using FGF < 1000 mL/min is significantly higher with desflurane as compared to isoflurane. Volatile anesthetic agent appears to be a factor for the decision making on the use of low flow anesthesia. [ABSTRACT FROM AUTHOR]- Published
- 2019
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10. Flexibility and Adaptability: Agrarian Expansion and Traditions of Water Management.
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Kumar, Mayank
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WATER supply management ,BOULDERS ,MATERIAL plasticity ,MONSOONS - Abstract
This paper explores the numerous methods of water harvesting in the semi-arid and arid conditions of Rajasthan. Considering the erratic nature of monsoon dependent rains, a closer examination of the traditional agricultural practices in pre-colonial Rajasthan suggest a certain level of plasticity inherent in their approach. It is evident in numerous methods of water harvesting, both for drinking and agricultural purposes. This paper simultaneously examines the role of a highly stratified community and state to bring out the complexity of their interactions with respect to various users/uses of water in pre-colonial Rajasthan. Usual questions of level of technology in pre-colonial times are being examined in terms of relevance and appropriateness for a given geographical and social landscape. The dynamics of agrarian production necessitated delineations of very complex interface between community participation and state intervention in the methods of water management. At a larger level this paper also tries to draw insights for the contemporary concerns. [ABSTRACT FROM AUTHOR]
- Published
- 2009
11. Situating the Environment: Settlement, Irrigation and Agriculture in Pre-colonial Rajasthan.
- Author
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Kumar, Mayank
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IRRIGATION & society ,CONCESSIONS (Administrative law) ,AGRICULTURAL productivity ,WATER laws ,IRRIGATION laws ,HISTORY - Abstract
The article discusses settlement, irrigation, and agriculture in pre-colonial Rajasthan in the Republic of India. The author talks about various systems of water management created by the state at a larger scale for irrigation and potable purposes. The article addresses the pre-colonial continuity of habitation through concessions and support to protect the revenue base. Subjects of the article also include Rajasthan's agricultural production, the state's socio-political power, and environment-related issues within this power.
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- 2008
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12. Study of secondary organic aerosol formation and aging using ambient air in an oxidation flow reactor during high pollution events over Delhi.
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Goel, Vikas, Tripathi, Nidhi, Gupta, Mansi, Sahu, Lokesh Kumar, Singh, Vikram, and Kumar, Mayank
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PROTON transfer reactions , *AIR flow , *ATMOSPHERIC aerosols , *AEROSOLS , *AGING , *VOLATILE organic compounds , *ETHANOL , *FORMALDEHYDE - Abstract
Secondary aerosols constitute a significant fraction of atmospheric aerosols, yet our understanding of their formation mechanism and fate is very limited. In this work, the secondary organic aerosol (SOA) formation and aging of ambient air of Delhi are studied using a potential aerosol mass (PAM) reactor, an oxidation flow reactor (OFR), coupled with aerosol chemical speciation monitor (ACSM), proton transfer reaction time of flight mass spectrometer (PTR-ToF-MS), and scanning mobility particle sizer with counter (SMPS + C). The setup mimics atmospheric aging of up to several days with the generation of OH radicals. Variations in primary volatile organic compounds (VOCs) and oxygenated volatile organic compounds (OVOCs) as a function of photochemical age were investigated. Primary VOCs such as benzene, toluene, xylene, trimethyl benzene, etc. decrease and OVOCs like formic acid, formaldehyde, acetone, ethanol, etc. increase substantially upon oxidation in OFR. The highest organic aerosol (OA) enhancement was observed for the 4.2 equivalent photochemical days of aging i.e., 1.84 times the ambient concentration, and net OA loss was observed at very high OH exposure, typically after 8.4 days of photochemical aging due to heterogeneous oxidation followed by fragmentation/evaporation. In ambient air, OA enhancement is highest during nighttime due to the high concentrations of precursor VOCs in the atmosphere. SMPS + C results demonstrated substantial new particle formation upon aging and decrement in preexisting aerosol mass. This is the first experimental study conducting an in-situ evaluation of potential SOA mass generated from the ambient aerosols in India. [Display omitted] • The OA concentration first increases and then decreases at high OH exposure. • Concentration of Primary VOCs decreases and OVOCs increases upon aging. • Elevated O:C ratios highlights the formation of more oxidized compounds during aging. • Aging increases the new particle formation and decreased the mass of pre-existing aerosols. [ABSTRACT FROM AUTHOR]
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- 2024
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13. Source apportionment, health risk assessment, and trajectory analysis of black carbon and light absorption properties of black and brown carbon in Delhi, India.
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Goel V, Jain S, Singh V, and Kumar M
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- Humans, Carbon analysis, Environmental Monitoring, Soot analysis, India, Risk Assessment, Air Pollutants analysis
- Abstract
Black Carbon (BC) is an important atmospheric pollutant, well recognized for adverse health and climatic effects. The present work discusses the monthly and seasonal variations of BC sources, health risks, and light absorption properties. The measurement was done from January to December 2021 using a seven wavelength aethalometer. Annual average BC concentration during the study period was 12.2 ± 8.8 μg/m
3 (ranged from 1.9 - 52.2 μg/m3 ). Results represent highest BC concentration during winter (W), followed by post-monsoon (P-M), summer (S), and monsoon (M) seasons where the fossil fuel (FF) combustion is the major source during W, S, and M seasons and biomass burning (BB) during the P-M season. The health risk assessment revealed that individuals in Delhi are exposed to BC levels equivalent to inhaling the smoke from 36 passively smoked cigarettes (PSC) everyday. The risk is highest during W reaching upto 71 PSC and minimum during M i.e., 9 PSC. The light absorption properties were calculated for BC (AbsBC ) and Brown carbon (AbsBrC ). AbsBC and varied from 229-89 Mm-1 between 370-950 nm and AbsBrC varied from 87-12 Mm-1 between 370-660 nm. AbsBC contributed substantially to total absorption at all wavelengths, while AbsBrC contribution is quite significant in the UV region only. Trajectory analysis confirmed significant influence of regional sources (e.g., biomass-burning aerosols from northwest and east direction) on air quality, health risks, and light absorption properties of BC over Delhi especially during the P-M season. The BB events of Punjab, Haryana, Uttar Pradesh, and eastern Pakistan seems to have significant influence on Delhi's air quality predominantly during P-M season., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2023
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14. Meteorology governs the variation of Delhi's high particulate-bound chloride levels.
- Author
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Manchanda C, Kumar M, and Singh V
- Subjects
- Chlorides, Environmental Monitoring, India, Particulate Matter analysis, Seasons, Air Pollutants analysis, Meteorology
- Abstract
A significant number of past studies have reported Delhi to witness some of the highest levels of particulate-bound chloride compared to anywhere else in the world. The present study employs long-term, highly time-resolved chloride measurements at the IIT Delhi campus from February 2020 to April 2021. The present work sheds light on the dependence of high chloride levels in Delhi on the winds from the northwest direction. The study makes use of linear regression models and stepped linear models to quantify the role of meteorological variables in driving the seasonal variation of chloride in Delhi. The results indicate that ∼85-88% of the variation in chloride concentration observed in Delhi can be attributed to meteorological parameters, mainly temperature (T), relative humidity (RH), and percentage of wind incoming from the northwest (%NW). The results also suggest that the primary chloride emissions remain relatively consistent year-round, and are regionally transported from Delhi's northwest. The results of this study provide valuable insights in understanding the nature of the sources and the variability associated with the chloride levels in Delhi and thus provide a basis for future emission control strategies., (Copyright © 2021. Published by Elsevier Ltd.)
- Published
- 2022
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15. Variation in chemical composition and sources of PM 2.5 during the COVID-19 lockdown in Delhi.
- Author
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Manchanda C, Kumar M, Singh V, Faisal M, Hazarika N, Shukla A, Lalchandani V, Goel V, Thamban N, Ganguly D, and Tripathi SN
- Subjects
- Aerosols analysis, Communicable Disease Control, Environmental Monitoring, Humans, India, Particulate Matter analysis, SARS-CoV-2, Seasons, Vehicle Emissions analysis, Air Pollutants analysis, COVID-19
- Abstract
The Government of India (GOI) announced a nationwide lockdown starting 25th March 2020 to contain the spread of COVID-19, leading to an unprecedented decline in anthropogenic activities and, in turn, improvements in ambient air quality. This is the first study to focus on highly time-resolved chemical speciation and source apportionment of PM
2.5 to assess the impact of the lockdown and subsequent relaxations on the sources of ambient PM2.5 in Delhi, India. The elemental, organic, and black carbon fractions of PM2.5 were measured at the IIT Delhi campus from February 2020 to May 2020. We report source apportionment results using positive matrix factorization (PMF) of organic and elemental fractions of PM2.5 during the different phases of the lockdown. The resolved sources such as vehicular emissions, domestic coal combustion, and semi-volatile oxygenated organic aerosol (SVOOA) were found to decrease by 96%, 95%, and 86%, respectively, during lockdown phase-1 as compared to pre-lockdown. An unforeseen rise in O3 concentrations with declining NOx levels was observed, similar to other parts of the globe, leading to the low-volatility oxygenated organic aerosols (LVOOA) increasing to almost double the pre-lockdown concentrations during the last phase of the lockdown. The effect of the lockdown was found to be less pronounced on other resolved sources like secondary chloride, power plants, dust-related, hydrocarbon-like organic aerosols (HOA), and biomass burning related emissions, which were also swayed by the changing meteorological conditions during the four lockdown phases. The results presented in this study provide a basis for future emission control strategies, quantifying the extent to which constraining certain anthropogenic activities can ameliorate the ambient air. These results have direct relevance to not only Delhi but the entire Indo-Gangetic plain (IGP), citing similar geographical and meteorological conditions common to the region along with overlapping regional emission sources. SUMMARY OF MAIN FINDINGS: We identify sources like vehicular emissions, domestic coal combustion, and semi-volatile oxygenated organic aerosol (SVOOA) to be severely impacted by the lockdown, whereas ozone levels and, in turn, low-volatility oxygenated organic aerosols (LVOOA) rise by more than 95% compared to the pre-lockdown concentrations during the last phase of the lockdown. However, other sources resolved in this study, like secondary chloride, power plants, dust-related, hydrocarbon-like organic aerosols (HOA), and biomass burning related emissions, were mainly driven by the changes in the meteorological conditions rather than the lockdown., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2021
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16. Variations in Black Carbon concentration and sources during COVID-19 lockdown in Delhi.
- Author
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Goel V, Hazarika N, Kumar M, Singh V, Thamban NM, and Tripathi SN
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- Aerosols analysis, Carbon analysis, Communicable Disease Control, Environmental Monitoring, Humans, India, Pandemics, Particulate Matter analysis, SARS-CoV-2, Air Pollutants analysis, COVID-19
- Abstract
A nationwide lockdown was imposed in India due to COVID-19 pandemic in five phases from 25th March to May 31, 2020. The lockdown restricted major anthropogenic activities, primarily vehicular and industrial, thereby reducing the particulate matter concentration. This work investigates the variation in Black Carbon (BC) concentration and its sources (primarily Fossil Fuel (ff) burning and Biomass Burning (bb)) over Delhi from 18th February to July 31, 2020, covering one month of pre-lockdown phase, all the lockdown phases, and two months of successive lockdown relaxations. The daily average BC concentration varied from 0.22 to 16.92 μg/m
3 , with a mean value of 3.62 ± 2.93 μg/m3 . During Pre-Lockdown (PL, 18th Feb-24th March 2020), Lockdown-1 (L1, 25th March-14th April 2020), Lockdown-2 (L2, 15th April-3rd May 2020), Lockdown-3 (L3, 4th-17th May 2020), Lockdown-4 (L4, 18th-31st May 2020), Unlock-1 (UN1, June 2020), and Unlock-2 (UN2, July 2020) the average BC concentrations were 7.93, 1.73, 2.59, 3.76, 3.26, 2.07, and 2.70 μg/m3 , respectively. During the lockdown and unlock phases, BC decreased up to 78% compared to the PL period. The BC source apportionment studies show that fossil fuel burning was the dominant BC source during the entire sampling period. From L1 to UN2 an increasing trend in BCff contribution was observed (except L3) due to the successive relaxations given to anthropogenic activities. BCff contribution dipped briefly during L3 due to the intensive crop residue burning events in neighboring states. CWT analysis showed that local emission sources were the dominant contributors to BC concentration over Delhi., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2021
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