68 research outputs found

    Assessment of Indoor & Outdoor Black Carbon Emissions Rural Areas of Indo-Gangetic Plain: Seasonal Characteristics, Source Apportionment and Radiative Forcing

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    Black Carbon (BC) has been widely recognized as the second largest source of territorial and global climate change as well as a threat to human health. There has been serious concern of BC emission and its impact in Indo-Gangetic Plains (IGP) due to the use of biomass and fossil fuels for cooking, transportation and industrial activities. An attempt has been made to study indoor (Liquefied Petroleum Gas- LPG & Traditional cookstoves users households) and outdoor concentrations; seasonal characteristics; radiative forcing and source of apportionment of BC in three districts (Sitapur, Patna and Murshidabad) of IGP during January to December 2016. The seasonal concentrations of BC in LPG (traditional cookstoves) users households were 3.79 ± 0.77 μgm−3 (25.36 ± 5.01 μgm−3) during the winter; 2.62 ± 0.60 μgm−3(16.36 ± 3.68 μgm−3) during the pre-monsoon; 2.02 ± 0.355 μgm−3(8.92 ± 1.98 μgm−3) during the monsoon and 2.19 ± 0.47 μgm−3(15.17 ± 3.31 μgm−3) during the post-monsoon seasons. However, the outdoor BC concentrations were 24.20 ± 4.46, 19.80 ± 4.34, 8.87 ± 1.83, and 9.14 ± 1.84 μgm−3 during winter, pre-monsoon, monsoon and post-monsoon seasons respectively. The negative radiative forcing (RF) at the surface suggests a cooling effect while a warming effect appears to be occurring at the top of the atmosphere. The atmospheric forcing of BC and aerosols also show a net warming effect in the selected study areas. The analysis of BC concentrations and fire episodes indicated that the emissions from biomass burning increases the pollution concentration. The backward trajectory analysis through the HYSPLIT model also suggests an additional source of pollutants during winter and pre-monsoon seasons from the northwest and northern region in the IGP

    Enhanced aerosol particle growth sustained by high continental chlorine emission in India

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    Many cities in India experience severe deterioration of air quality in winter. Particulate matter is a key atmospheric pollutant that impacts millions of people. In particular, the high mass concentration of particulate matter reduces visibility, which has severely damaged the economy and endangered human lives. But the underlying chemical mechanisms and physical processes responsible for initiating haze and fog formation remain poorly understood. Here we present the measurement results of chemical composition of particulate matter in Delhi and Chennai. We find persistently high chloride in Delhi and episodically high chloride in Chennai. These measurements, combined with thermodynamic modelling, suggest that in the presence of excess ammonia in Delhi, high local emission of hydrochloric acid partitions into aerosol water. The highly water-absorbing and soluble chloride in the aqueous phase substantially enhances aerosol water uptake through co-condensation, which sustains particle growth, leading to haze and fog formation. We therefore suggest that the high local concentration of gas-phase hydrochloric acid, possibly emitted from plastic-contained waste burning and industry, causes some 50% of the reduced visibility. Our work implies that identifying and regulating gaseous hydrochloric acid emissions could be critical to improve visibility and human health in India

    Crop Residue Burning in Northern India: Increasing Threat to Greater India

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    Crop residue burning (CRB) is a recurring problem, during October–November, in the northwestern regions (Punjab, Haryana, and western Uttar Pradesh) of India. The emissions from the CRB source regions spread in all directions through long-range transport mechanisms, depending upon the meteorological conditions. In recent years, numerous studies have been carried out dealing with the impact of CRB on the air quality of Delhi and surrounding areas, especially in the Indo-Gangetic Basin (also referred to as Indo-Gangetic Plain). In this paper, we present detailed analysis using both satellite- and ground-based sources, which show an increasing impact of CRB over the eastern parts of the Indo-Gangetic Basin and also over parts of central and southern India. The increasing trends of finer black carbon particles and greenhouse gases have accelerated since the year 2010 onward, which is confirmed by the observation of different wavelength dependent aerosol properties. Our study shows an increased risk to ambient air quality and an increased spatiotemporal extent of pollutants in recent years, from CRB, which could be a severe health threat to the population of these regions

    How does the composition of atmospheric aerosol particles affect PM2.5 toxicity?

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    Epidemiological studies have shown that exposure to PM2.5 increases the chance of mortality or morbidity due to respiratory and cardiovascular diseases. The causes for this are not completely understood yet, however, one widely proposed biochemical pathway is PM2.5-induced oxidative stress. This study aims to determine the impact of PM2.5 concentration on the oxidative potential (OP) of the air mass, and the effect of PM chemical composition on the intrinsic OP of PM2.5 particles. These factors were investigated through several intensive periods of PM2.5 measurement across different seasons in Beijing and Delhi, with a shorter campaign in Birmingham, followed by detailed laboratory chemical analysis, and application of an OP assay to the collected PM samples. The dithiothreitol (DTT) assay was chosen as the method for OP determination and a laboratory protocol was developed, meeting the requirements and limitations of the project and available laboratories. This protocol was validated using PM2.5 samples collected during a short sampling campaign in Birmingham. PM2.5 concentration was found to be strongly correlated with air mass OP (DTTv, nmol DTT min-1 m-3) at lower PM¬2.5 concentrations (r = 0.85 at 110.6 µg m-3). This was due to an inverse relationship between PM2.5 concentration and intrinsic toxicity (DTTm, pmol DTT min-1 µg-1 PM2.5) at higher PM2.5 concentrations (r = -0.47). During some extreme PM2.5 pollution events DTTv values were lower than those seen during much lower PM2.5 concentration days, demonstrating the importance of intrinsic PM OP to human exposure (DTTv) and consequent health effects. The relative impact of different PM chemical components on DTTm was determined through various correlation, multiple linear regression, and t-test analyses performed on composition measurements within PM, and meteorological and gas-phase data for the Beijing and Delhi campaigns. The impact of these species and meteorological conditions on DTTm was determined by the gradient of their correlation with DTTm, the gradient for each species was denoted by DTTmspecie (i.e. DTTmFe representing pmol DTT min-1 ng-1 Fe). Data from all campaigns showed significant correlations between vehicle related emissions and DTTm. Crustal material, re-suspended road dust, and non-exhaust vehicle emissions were also significantly correlated with DTTm during the Beijing winter and all Delhi campaigns. Species most commonly associated with these sources consistently showed the highest gradients such as Ce, Cr, Ni, and Sr. During the Delhi autumn campaign biomass burning is the dominant source of PM2.5. Biomass associated species such as OC and K showed a weaker effect on OP assessed as DTTm values, compared with non-exhaust vehicle emissions and crustal materials i.e. 0.153 ± 0.023 DTTmOC compared to 358 ± 34 DTTmCe. Multiple linear regression analysis showed that 78 % of DTTm variance was accounted for by non-exhaust vehicle emissions in this campaign. This study shows that PM2.5 concentration is key in determining the overall oxidative potential of the air, however, it is not sufficient to solely predict this oxidative potential. The sources and composition of the particulate matter must also be considered to better predict the health effects of particulate matter oxidative potential

    Dynamic Characteristics of Aerosol Optical Properties over Dibrugarh City in the North-Eastern Indian Region during 2018–2021

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    Aerosols play an important role in the earth\u27s environment across the globe through their involvement in various earth system cycles. The change in the aerosol properties may cause short and long-term impacts, the knowledge of such changes is useful in the estimation of the pollution sources of any region. We have carried out the analysis of the aerosols\u27 optical and radiative properties using AERONET station data from 2018 to 2021 in Dibrugarh City. The higher Aerosol Optical Depth (AOD) values during winter and pre-monsoon months indicate high anthropogenic activities, and biomass burning in Dibrugarh. The impact of various sources and daily meteorological parameters help in understanding the diurnal variations of the AOD, Ångström Exponent (AE), and column water (CW). Fine aerosol fractions dominate the aerosol volume, but sometimes the long-range transport of dust affects aerosol properties during pre-monsoon months (MAM). MODIS-derived AOD and AERONET AOD values show a good correlation, with R2 = 0.68. The highest volume of the aerosols reaches up to 0.11 µm3 µm–2 during pre-monsoon months, whereas it lies below 0.05 µm3 µm–2 in other seasons. SSA values indicate the presence of scattering aerosols but in 2020, a sudden decline in the SSA values shows a strong rise in the absorbing aerosols. Throughout the study period (2018–2021), the positive radiative forcing indicates a rise in atmospheric heating

    Community library programs that work: Building youth and family literacy

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    A collection of versatile best practices for promoting literacy development by utilizing local community connections in school and public libraries. This book provides a fresh approach to learning as well as guidelines for creating dynamic and relevant library programs for children, teens, and families. Organized thematically, each chapter includes relevant topical research and three to eight community-focused approaches. Programs range from small, single-library initiatives in rural communities to multi-site, cross-border initiatives. This resource includes collaborative and locally inspired programs, many of which can be scaled to the budget of any library, school, or community organization

    The colonial city and the challenge of modernity : urban hegemonies and civic contestations in Bombay City, 1905-1925

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    This thesis is a social history of Bombay city in the first quarter of the twentieth century. It explores material changes in urban life consequent upon the impact of modernity and the varied range of contestations of the colonial order which they provoke. The first chapter outlines the specific nature of colonial modernism and shows its impact on the city's spatial forms and on its social relations. Representing a highly selective, power-driven, and essentially technological manipulation of modernity, it ensures distorted and differential outcomes within urban society. These conditions are considerably aggravated by the sudden impact of the First World War, the subject of the second chapter. The War increases material scarcities, worsens conditions of urban life, widens disparities between rich and poor, and intensifies colonial repression. At the same time, the crisis of war brings to the city the full potential of the revolution in communications which carries a modem discourse of civic rights. In the city, Homiman and sections of the bilingual urban intelligentsia rapidly vernacularize this discourse and diffuse it into new social contexts. This is perceived by the local colonial state as seriously threatening and subversive. The third chapter shows how Gandhi's anti-modernist rejection of the city leads to his attempts to control, and in some aspects reverse, this gathering urban momentum for an expansion in citizenship rights. The final chapter considers the new visions of urban citizenship expressed in the agitation for an expansion of civil and democratic rights, and in labour protest movements. This critical modernism looks to the future, rather than to the past, and acts as a force to humanise the city, presenting an alternative and potentially more radical challenge to the colonial state than the Gandhian movement

    TRAILS OF AN INDIAN COMMUNITY IN PADOVA. Chasing the invisible migration of Indian students (re)shaping spaces in this Italian medium city.

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    L\u2019Italia viene spesso considerata come un paese che ospita o riceve migranti poco qualificati (per lo pi\uf9 illegali), cos\uec nel corso degli anni mi sono trovata a spiegare in pi\uf9 occasioni che anche migranti altamente qualificati sono attratti dall\u2019Italia, e che addirittura vi giungono grazie ad accordi internazionali stipulati da paesi che sono tra loro in competizione \u2018soft power\u2019 per la ricerca di talenti, con lo scopo di aumentare il proprio potere a livello globale, ovviamente attraverso vie legali. Gli studenti internazionali costituiscono una categoria di migranti che fino agli anni duemila non ha ricevuto molta attenzione in ambito accademico [Piguet et al., 2017]. Tuttavia, la migrazione per motivi di studio si pu\uf2 far risalire al 1190, e, forse ancora pi\uf9 precisamente, al periodo coloniale tra il XVII e il XIX secolo [Leucci et al., 2018]. A questo proposito, la presente tesi ha evidenziato come il flusso di studenti indiani verso l\u2019Italia sia largamente incoraggiato da politiche internazionali che rimangono per lo pi\uf9 sconosciute. Tra queste politiche figurano vari accordi bilaterali firmati dal Governo italiano per attirare studenti indiani di livello universitario che vogliano \u201cinvestire il proprio talento\u201d nelle Universit\ue0 italiane. La tesi riesce a coniugare, attraverso un case study sulla citt\ue0 di Padova \u2013 citt\ue0 di \u2018media\u2019 dimensione che sta guadagnando importanza nel panorama internazionale grazie alla sua Universit\ue0, fondata 800 anni fa - due livelli di analisi (locale e globale) in un\u2019unica discussione sulle interdipendenze tra l\u2019andamento e la struttura dei flussi migratori degli studenti indiani e la loro spazializzazione in Italia quale nazione di destinazione. La tesi presentata contribuisce quindi ad evidenziare un flusso migratorio rilevante ma inesplorato dalla letteratura accademica in Italia: la migrazione degli studenti internazionali. Allo stesso tempo, un focus sugli studenti universitari indiani, considerati come studenti-migranti dotati di conoscenze e capacit\ue0 intellettuali, aiuter\ue0 a delineare il variegato mosaico dell\u2019attuale migrazione indiana in Italia. In effetti, l\u2019analisi della migrazione degli indiani in Italia resta attualmente limitata a migranti con bassi o medi livelli di specializzazione come, ad esempio, gli indiani Sikh impiegati in agricoltura. In linea generale, la migrazione di lavoratori altamente qualificati e con alti livelli di istruzione non \ue8 stata studiata in modo approfondito n\ue9 in Italia, n\ue9 in altri paesi europei [Piguet, 2016; McGuill, 2013; King and Raghuram, 2013]. Pertanto, richiamo la necessit\ue0 di definire un diverso modo di pensare, interpretare e agire che superi l\u2019approccio limitante alla migrazione generalmente associato ai soli irregolari [Ambrosini, 2011, 2017; Panichella & Ambrosini, 2018]. La tesi colma inoltre un\u2019importante lacuna, valutando gli impatti negativi del processo di studentificazione di una citt\ue0 come Padova che ricerca il proprio riconoscimento a livello internazionale, aldil\ue0 del suo patrimonio storico noto globalmente per la basilica di Sant\u2019Antonio. In questo contesto, ci tengo a sottolineare come il ruolo illustre dell\u2019Universit\ue0 e il suo spazio fisico fungano da \u201cponte\u201d, o da crocevia e punto di convergenza dell\u2019interculturalit\ue0 della citt\ue0. Nel complesso, la presente tesi di ricerca fornisce un quadro dettagliato e ricco di sfumature sui vari profili degli studenti indiani presenti in uno stesso territorio, cio\ue8 la citt\ue0 di Padova. Questa ricerca mira invece a portare il lettore ad una nuova visione di co-abitazione in uno spazio locale limitato, grazie all\u2019esempio della citt\ue0 di Padova e del suo interessante desiderio di internazionalizzazione che coinvolge l\u2019Universit\ue0 nel processo
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