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Showing papers by "Prashant Kumar published in 2015"


Journal ArticleDOI
TL;DR: The drivers behind current rises in the use of low-cost sensors for air pollution management in cities are illustrated, while addressing the major challenges for their effective implementation.

591 citations


Journal ArticleDOI
TL;DR: In this paper, a review brings together a collective of methods that have demonstrated an ability to influence air flow patterns to reduce personal exposure in the built environment, including trees and vegetation, noise barriers, low boundary walls and parked cars.

153 citations


01 Feb 2015
TL;DR: In this article, the authors illustrate the drivers behind current rises in the use of low-cost sensors for air pollution management in cities, whilst addressing the major challenges for their effective implementation.
Abstract: Ever growing populations in cities are associated with a major increase in road vehicles and air pollution. The overall high levels of urban air pollution have been shown to be of a significant risk to city dwellers. However, the impacts of very high but temporally and spatially restricted pollution, and thus exposure, are still poorly understood. Conventional approaches to air quality monitoring are based on networks of static and sparse measurement stations. However, these are prohibitively expensive to capture tempo-spatial heterogeneity and identify pollution hotspots, which is required for the development of robust real-time strategies for exposure control. Current progress in developing low-cost micro-scale sensing technology is radically changing the conventional approach to allow real-time information in a capillary form. But the question remains whether there is value in the less accurate data they generate. This article illustrates the drivers behind current rises in the use of low-cost sensors for air pollution management in cities, whilst addressing the major challenges for their effective implementation.

136 citations


Journal ArticleDOI
TL;DR: A review of the various groundwater vulnerability assessment models developed across the world can be found in this article, where each model has been evaluated in terms of its pros and cons and the environmental conditions of its application.

125 citations


Journal ArticleDOI
TL;DR: In this article, the authors provided a comprehensive synthesis of the currently available published information which dealt with atmospheric particulate matter (PM) in the Middle East Area (MEA) and provided a focus on the PM sources, monitoring, health impacts and source apportionment.
Abstract: Rapid economic expansion, industrialization, urbanisation and construction in the Middle East Area (MEA) have led to an increase in the levels of air pollution, resulting in serious effects on human health. For the first time, this article provides a comprehensive synthesis of the currently available published information which deals with atmospheric particulate matter (PM) in MEA. The focus of the article remains on the PM sources, monitoring, health impacts and source apportionment. The key objectives are to identify the levels of PM pollution and the associated exposure risks, to highlight research gaps and to discuss future research directions. The limited number of monitoring studies available for MEA indicates that dust storms augmented by the rapid increase in urban population are the key reasons for the high PM concentration levels. The findings of reviewed monitoring studies suggest that the levels of both annual mean PM10 (20 μg/m3) and PM2.5 (10 μg/m3) concentrations exceed the World Health Organization (WHO) guidelines during most of the non-dust storm episodes, and as expected, the PM pollution levels become even higher during dust storm episodes. For example, 24-h mean PM10 concentrations of over 1,000 μg/m3 were noted during a severe dust storm episode in Kuwait. The findings of the epidemiological and toxicological studies in MEA have shown that dust storm events have a significant impact on respiratory admissions and the adverse health effects of PM are particularly in the form of asthma and respiratory and cardiovascular diseases. It is concluded that PM pollution in MEA is a significant problem and quantification of PM emissions and the design of control measures to abate their impacts on public health are of primary importance. Besides, there is a need for more systematic PM data collection for source apportionment and assessment of PM levels that would enable air pollution-related health impact assessments of MEA. Furthermore, this review highlights that the release of airborne PM from major building activities such as building construction is largely unknown and emission inventories for different situations are needed.

108 citations


Journal ArticleDOI
TL;DR: The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies.

108 citations


Journal ArticleDOI
TL;DR: In this article, chemical looping combustion (CLC), pre-combustion and oxy-fuel combustion technologies are compared to those of a conventional IGCC plant without CO2 capture.
Abstract: Carbon dioxide (CO2) emitted from conventional coal-based power plants is a growing concern for the environment. Chemical looping combustion (CLC), pre-combustion and oxy-fuel combustion are promising CO2 capture technologies which allow clean electricity generation from coal in an integrated gasification combined cycle (IGCC) power plant. This work compares the characteristics of the above three capture technologies to those of a conventional IGCC plant without CO2 capture. CLC technology is also investigated for two different process configurations—(i) an integrated gasification combined cycle coupled with chemical looping combustion (IGCC–CLC), and (ii) coal direct chemical looping combustion (CDCLC)—using exergy analysis to exploit the complete potential of CLC. Power output, net electrical efficiency and CO2 capture efficiency are the key parameters investigated for the assessment. Flowsheet models of five different types of IGCC power plants, (four with and one without CO2 capture), were developed in the Aspen plus simulation package. The results indicate that with respect to conventional IGCC power plant, IGCC–CLC exhibited an energy penalty of 4.5%, compared with 7.1% and 9.1% for pre-combustion and oxy-fuel combustion technologies, respectively. IGCC–CLC and oxy-fuel combustion technologies achieved an overall CO2 capture rate of ∼100% whereas pre-combustion technology could capture ∼94.8%. Modification of IGCC–CLC into CDCLC tends to increase the net electrical efficiency by 4.7% while maintaining 100% CO2 capture rate. A detailed exergy analysis performed on the two CLC process configurations (IGCC–CLC and CDCLC) and conventional IGCC process demonstrates that CLC technology can be thermodynamically as efficient as a conventional IGCC process.

93 citations


Journal ArticleDOI
TL;DR: In this paper, the authors carried out mobile measurements in a car for size-resolved particle number concentrations (PNCs) in the 5-560 nm range under five different ventilation settings on a 6 km long busy round route with 10 intersections.

83 citations


01 Jan 2015
TL;DR: The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies.
Abstract: Most major cities around the world experience periods of elevated air pollution levels, which exceed international health-based air quality standards (Kumar et al., 2013). Although it is a global problem, some of the highest air pollution levels are found in rapidly expanding cities in India and China. The sources, emissions, transformations and broad effects of meteorology on air pollution are reasonably well accounted in air quality control strategies in many developed cities; however these key factors remain poorly constrained in the growing cities of countries with emerging economies. We focus here on Delhi, one of the largest global population centres, which faces particular air pollution challenges, now and in the future.

80 citations


Journal ArticleDOI
TL;DR: Size-resolved measurements of particle number distributions (PNDs) and concentrations (PNCs) in the 5-1000 nm size range in Kuwait could serve as reference data to design more detailed field studies in the future and treat these sources in dispersion modelling and health impact assessment studies.
Abstract: Airborne nanoparticles have been studied worldwide, but little is known about their sources in the Middle East region, where hot, arid and dusty climatic conditions generally prevail. For the first time in Kuwait, we carried out size-resolved measurements of particle number distributions (PNDs) and concentrations (PNCs) in the 5–1000 nm size range. Measurements were made continuously for 31 days during the summer months of May and June 2013 using a fast-response differential mobility spectrometer (Cambustion DMS500) at a sampling rate of 10 Hz. Sources and their contributions were identified using the positive matrix factorization (PMF) approach that was applied to the PND data. Simultaneous measurements of gaseous pollutants (i.e., O3, NO, NOx, SO2 and CO), PM10, wind speed and direction were also carried out to aid the interpretation of the PMF results through the conditional probability function plots and Pearson product–moment correlations. Six major sources of PNCs were identified, contributing ∼46% (fresh traffic emissions), 27% (aged traffic emissions), 9% (industrial emissions), 9% (regional background), 6% (miscellaneous sources) and 3% (Arabian dust transport) of the total PNCs. The sources of nanoparticles and their PND profiles identified could serve as reference data to design more detailed field studies in the future and treat these sources in dispersion modelling and health impact assessment studies.

52 citations


Journal ArticleDOI
TL;DR: In this article, the authors examined long-term measurements of major criteria pollutants concentrations in an urban station in South-Eastern Mediterranean, in Nicosia- Cyprus, which is susceptible both to transboundary air pollution transport from Sahara-dust events as well as to evaporative transport of sea-sprays.

Journal ArticleDOI
TL;DR: In this article, the performance of five different oxygen carriers (OCs) for large-scale (350-400 MW) integrated gasification combined cycle (IGCC-CLC) processes through simulation studies is evaluated.

Journal ArticleDOI
TL;DR: In this article, the authors carried out mobile measurements inside the car cabin with windows fully open for size resolved particle number concentrations (PNCs) in the 5-560nm range on a 6-km long busy round route that had 10 TIs.

Journal ArticleDOI
TL;DR: The results confirm that refurbishment activities produce significant levels (both number and mass) of airborne particles, indicating a need to develop appropriate regulations for the control of occupational exposure of operatives undertaking building refurbishment as discussed by the authors.
Abstract: Understanding of the emissions of coarse (PM 10 ≤10 μm), fine (PM 2.5 ≤2.5 μm) and ultrafine particles (UFP 90 % of the total particle number concentrations and <10 % of the total mass concentrations released during the recorded activities. The highest UFP concentrations were 4860, 740, 650 and 500 times above the background value during wall-chasing, drilling, cementing and general demolition activities, respectively. Scanning electron microscopy, X-ray photoelectron spectroscopy and ion beam analysis were used to identify physicochemical characteristics of particles and attribute them to probable sources considering the size and the nature of the particles. The results confirm that refurbishment activities produce significant levels (both number and mass) of airborne particles, indicating a need to develop appropriate regulations for the control of occupational exposure of operatives undertaking building refurbishment. Graphical Abstract: [Figure not available: see fulltext.]

Journal ArticleDOI
TL;DR: Recent advances have improved the ability to diagnose latent infection and active TB in children, nevertheless establishing a diagnosis of either latent infection or active disease in HIV-infected children remains a major challenge.
Abstract: Despite over 2.3 million (26% of global burden) cases of tuberculosis (TB) in India the accurate diagnosis of childhood TB remains a major challenge. Children with TB usually have paucibacillary disease and contribute little to disease transmission within the community. Consequently the treatment of children with TB is often not considered a priority by TB control programmes. Adequate and timely assessment of TB infection in childhood could diminish epidemiological burden as underdiagnosed pediatric patients can eventually evolve in to an active state and have the potential to disseminate the etiological agent Mycobacterium tuberculosis, notably increasing this worldwide public health problem. In this review we discuss the most important recent advances in the diagnosis of childhood TB: (1) Symptom-based approaches, (2) novel immune-based approaches, including in vitro interferon-γ IGRA release assays IGRA tests; and (3) bacteriological and molecular methods that are more rapid and/or less expensive than conventional culture techniques for TB diagnosis and/or drug-resistance testing. Recent advances have improved our ability to diagnose latent infection and active TB in children, nevertheless establishing a diagnosis of either latent infection or active disease in HIV-infected children remains a major challenge.

Journal ArticleDOI
TL;DR: In this article, a typical thermal power plant operated using a solid biomass mixture as fuel, which comprised 70-80% gram straw, 10-15% cotton straw, 5-10% wheat straw and leaves with a small quantity of coal (1-2%) initially used for smooth ignition, produces a residue called Biomass-Based Thermal Power Plant Fly Ash (BBTPFS) BBTPFS was investigated for composition and structural characterization using different techniques.
Abstract: A typical thermal power plant operated using a solid biomass mixture as fuel, which comprised 70–80% gram straw, 10–15% cotton straw, 5–10% wheat straw and leaves (2%) with a small quantity of coal (1–2%) initially used for smooth ignition, produces a residue called Biomass-Based Thermal Power Plant Fly Ash (BBTPFS) BBTPFS was investigated for composition and structural characterization using different techniques The versatile composition of the BBTPFS was confirmed by XRF analysis that indicated the weight percent of different components viz CaO (3074%), SiO2 (2787%), K2O (1396%), MgO (667%), SO3 (483%), Cl (336%), Al2O3 (283%), Fe2O3 (236%), P2O5 (134%), Na2O (114%), small quantities of TiO2, SrO, MnO, BaO, ZrO2, ZnO, Rb2O, Br, Cr2O3, CuO, NiO and As2O3 as active ingredients The SEM and TEM image analysis showed the surface morphology of the BBTPFS which was found to be mixed in nature, having 1 to 500 nm range particles with meso, micro and macro porosity BBTPFS was used as a catalyst for transesterification of Jatropha curcas oil having a high percentage of free fatty acids and appropriate process optimization was achieved using the Taguchi-ANOVA method It was observed that at a temperature of 225 °C and an internal vapour pressure of 32 MPa in a batch reactor with 5% catalyst loading, 1:9 mol mol−1 of oil–alcohol and 3 h reaction time, the optimum yield of biodiesel obtained was ∼939%, which is in agreement with the theoretical value The product quality was assessed and found to conform to ASTM and EN-standards

Journal ArticleDOI
TL;DR: In this article, the authors developed an emission inventory of methane (CH4), nitrous oxide (N2O), ammonia (NH3), nitrogen oxides (NO, NO2) and CO2 from various agricultural activities and wetlands in Delhi area using an emission factor and activity based approach between the years 2001 and 2011.

Journal ArticleDOI
TL;DR: Combined use of phenytoin and carbamezepine as a most important risk factor for serious CADR like SJS and TEN like TEN and SSJS is identified in this study.
Abstract: Introduction: Cutaneous manifestations of adverse drug reactions are a common occurrence and need to be differentiated from other causes of similar manifestations. Antiepileptic drugs (AED) usually are responsible for severe cutaneous adverse drug reactions (CADR) like Stevens-Johnson Syndrome/Toxic epidermal necrolysis (SJS/TEN) and drug rash with eosinophillia and systemic symptoms (DRESS). There is paucity of published research regarding morphological pattern of CADR due to various antiepileptic drugs AED. Objective: To study the morphological patterns of CADR due to AED and common anticonvulsant drugs implicated particularly in severe CADR such as SJS/TEN and DRESS in a tertiary care teaching hospital in eastern India. Materials and Methods: A prospective, observational study was conducted over a period of 4 years from August 2009 to July 2013 after the approval of the Institutional Ethics Committee using self-reporting method for selection of cases. Settings: All patients with CADR after AED consumption for various conditions presenting to the Dermatology outpatient department (OPD) and Pediatric OPD and Indoor patients of a tertiary care teaching hospital located in Rohtas district of Bihar were included in this study. Results: During the study period, 64 cases of severe CADRs were included in this study. Out of 64 patients, 28 were male and 36 were female with mean age 36.1 years (range 6 years to 72 years). Most common AED implicated for CADR was Phenytoin. Maculopapular rash was the most common cutaneous manifestation of ADRs (42.85%). Serious CADR like TEN and SSJS were more likely in patients prescribed Phenytoin and Carbemazepine simultaneously. Conclusion: CADRs are a common occurrence and awareness about the same is essential for diagnosis and prevention. This study identified combined use of phenytoin and carbamezepine as a most important risk factor for serious CADR like SJS and TEN.

Journal ArticleDOI
TL;DR: UFP can be estimated with good accuracy based on NOx measurements at the same location; it is possible to estimate UFP at one location based on measurements of NOx or U FP at two remote locations; the addition of remote UFP to local NOx, O3 or CO measurements improves models' performance.

Proceedings ArticleDOI
10 Jul 2015
TL;DR: In this paper, an approach to develop an empirical equation to predict the pollution potential of river water is presented, which uses pH, conductivity, Dissolved Oxygen, Biological Oxygen Demand (BOD), Chemical Oxygen demand (COD), Total Coliform and Fecal Coliform.
Abstract: Over the years the surface water quality of Indian rivers has been degrading. There are various reasons for the degradation of quality of river waters in Indian conditions. The pollution potential of river water involves various factors such as pH, Conductivity, Dissolved Oxygen, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Coliform and Fecal Coliform. The paper presents an approach to develop an empirical equation to predict the pollution potential of river water. The empirical equation developed uses aforementioned factors as variables. These variables have been assigned various ratings on a scale of 1–3 according to standard pollution potential charts. The pollution potential predicted using this empirical equation is in congruence with the current potential pollution of Indian rivers.

Journal ArticleDOI
TL;DR: Kumar et al. as mentioned in this paper reviewed 60 research articles and patents for developing industrial scale heterogeneous catalytic pilot plant facilities for biodiesel production, and the findings are analyzed in this article.
Abstract: The efficient and economic utilization of natural renewable and waste materials of various industries and biomass having non-homogeneous composition is a new dimension of research for biodiesel pro- duction. A combination of these renewable, waste materials and traditional heterogeneous catalyst can also be looked after for the possible solution of heterogeneous catalytic transesterification. This review discusses industrially derived and naturally occurring materials containing calcium, sodium, potassium etc, which were found instrumental for biodiesel production. About 60 research articles and patents have been reviewed and the findings are analysed in this article for developing industrial scale heterogeneous catalytic pilot plant facilities for biodiesel production. © 2015 BCREC UNDIP. All rights reserved. Received: 25th May 2015; Revised: 17th June 2015; Accepted: 10th July 2015 How to Cite : Kumar, P., Sarma, A.K., Jha, M.K., Bansal, A., Srivasatava, B. (2015). Production Utilization of Renewable and Waste Materials for Biodiesel Production as Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis , 10 (3): 221-229. (doi:10.9767/bcrec.10.3.8584.221-229) Permalink/DOI : http://dx.doi.org/10.9767/bcrec.10.3.8584.221-229

Journal Article
TL;DR: In this article, the effect of climate pollutants in the air as they affect weathering steel in rural, urban and industrial environment was looked at and the overall objective of this work is to underscore the factors that have impact on the progressive deterioration of materials exposed to atmospheric weathering.
Abstract: Ever since industrial revolution, the world climatic conditions have been deteriorating due to the ever increasing amount of air pollutants injected into the atmosphere. This has adversely affected the health of living organism, plants and the environment that host them. Building structures are not left out in the devastating effects of air pollution as metallic components are easily oxidized leading to corrosion. Corrosion of steel materials due to environmental pollutants has become an issue of great concern to researchers all over the world. This paper looked at the effect of climate pollutants in the air as they affect weathering steel in rural, urban and industrial environment. The corrosion process in steel over time and how it varies in rural, urban and industrial environments were considered. The overall objective of this work is to underscore the factors that have impact on the progressive deterioration of materials exposed to atmospheric weathering. The climate and air pollution parameters that affect material losses are identified and their numeric values obtained vie dose response functions. The results obtained show that �5�1 �6 corrosion rate of industrial environment is about five times that of rural environment while that of industrial to urban and urban to rural corrosion rates are slightly above two times for each.

Journal ArticleDOI
TL;DR: E-cadherin showed more efficient force-induced self-strengthening of interactions than cadherin 7 and the distributions of the unbinding forces for both cadherins partially overlap with those of the unfolding forces, indicating that partial unfolding/deformation of the cadher in EC domains may take place during their homophilic interactions.

Posted Content
TL;DR: In this paper, the Ginzburg-Landau theory and its extensions describe the fluctuating regime of regular metallic superconductors, and the associated dynamics of the pair amplitude and the phase.
Abstract: In the vicinity of a phase transition, the order parameter starts fluctuating before vanishing at the critical point. The fluctuation regime, i.e. the way the ordered phase disappears, is a characteristics of a transition, and determines the universality class it belongs to. This is valid for thermal transitions, but also for zero temperature Quantum Phase Transitions (QPT). In the case of superconductivity, the order parameter has an amplitude and a phase, which can both fluctuate according to well identified scenarios. The Ginzburg-Landau theory and its extensions describe the fluctuating regime of regular metallic superconductors, and the associated dynamics of the pair amplitude and the phase. When the system is two-dimensional and/or very disordered, phase fluctuations dominate. Here, we address the possibility that a new type of fluctuations occurs in superconductors with an anomalous dynamics. In particular we show that the superconducting to metal QPT that occurs upon changing the gate voltage in two-dimensional electron gases at LAO/STO and LTO/STO interfaces displays anomalous scaling properties, which can be explained by density driven superconducting critical fluctuations. A Finite Size Scaling (FSS) analysis reveals that the product this http URL (nu is the correlation length exponent and z the dynamical critical one) is this http URL = 3/2. We argue that critical superconducting fluctuations acquire an anomalous dynamics with z=3, since they couple to density ones in the vicinity of a spontaneous electronic phase separation, and that nu=1/2 corresponds to the mean-field value. This approach strongly departs from the conventional z=1 scenario in disordered 2D systems based on long-range Coulomb interactions with dominant phase fluctuations. This scenario can explain recent data in LSCO ultra-thin films, and apply to a whole class of two-dimensional superconductors.

Proceedings ArticleDOI
15 May 2015
TL;DR: The purpose of the module is to introduce encryption/decryption features with key sharing into network simulation program and the simulation details of key sharing protocol and self-defined encryption/Decryption protocol in wired network are introduced.
Abstract: NS2 is an event-driven, object-oriented simulation tool to simulate and analyze dynamic nature of communication networks; it is also a powerful tool to develop new protocols and functions. NS-2 is an open source and very popular network simulation tool. It provides support for OSI or TCP/IP protocols stack and many standard routing and application protocols for wire and wireless networks. In NS2, many protocols have been implemented so far at various layer of TCP/IP protocol suite to provide different functions, but none provides security functions. Although, some applications require security (Encryption/Decryption and key exchange) implementation in NS-2. However, NS-2 does not provide these features till now. In this paper, we solve this issue by adding new security module or protocol in NS2. Security module helps us in key sharing as well as in implementation of encryption/decryption functions. We analyze the features of a security module in details; discuss the algorithms used, simulation process and implementation of a security module on the basis of NS2. Also, the simulation details of key sharing protocol and self-defined encryption/decryption protocol in wired network are introduced. NAM is used to display the process of simulation. The purpose of the module is to introduce encryption/decryption features with key sharing into network simulation program.

01 Jan 2015
TL;DR: The relationship between somatic symptoms and depression in patients diagnosed with major depressive disorder (MDD) is characterized and treatment of both is necessary to optimize clinical outcomes.
Abstract: Somatic symptoms account for over half of all primary care visits and are often medically unexplained as well as chronic or recurrent. Unexplained, persistent, or multiple somatic symptoms are frequently a marker for an underlying depressive disorder. Depression is often unrecognized and hence not treated due to occurrence of somatic symptoms. Proper identification of depression relevant somatic symptoms is important for accurate diagnosis of depression and development of treatment strategies. The presence of somatic symptoms may worsen patient‟s prognosis. When somatic and psychological symptoms coexist, treatment of both is necessary to optimize clinical outcomes. The objective of this study was to characterize the relationship between somatic symptoms and depression in patients diagnosed with major depressive disorder (MDD).