Chemical characterization of PM₁₀ and PM₂.₅ mass concentrations emitted by heterogeneous traffic

In this paper, the chemical characterization of PM₁₀ and PM_2.5 mass concentrations emitted by heterogeneous traffic in Chennai city during monsoon, winter and summer seasons were analysed. The 24-h averages of PM₁₀ and PM_2.5 mass concentrations, showed higher concentrations during the winter season (PM₁₀ = 98 μg/m³; PM_2.5 = 74 μg/m³) followed by the monsoon (PM₁₀ = 87 μg/m³; PM_2.5 = 56 μg/m³) and summer (PM₁₀ = 77 μg/m³; PM_2.5 = 67 μg/m³) seasons. The assessment of 24-h average PM₁₀ and PM_2.5 concentrations was indicated as violation of the world health organization (WHO standard for PM₁₀ = 50 μg/m³ and PM_2.5 = 25 μg/m³) and Indian national ambient air quality standards (NAAQS for PM₁₀ = 100 μg/m³ and PM_2.5 = 60 μg/m³).The chemicals characterization of PM₁₀ and PM_2.5 samples (22 samples) for each season were made for water soluble ions using Ion Chromatography (IC) and trace metals by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) instrument. Results showed the dominance of crustal elements (Ca, Mg, Al, Fe and K), followed by marine aerosols (Na and K) and trace elements (Zn, Ba, Be, Ca, Cd, Co, Cr, Cu, Mn, Ni, Pb, Se, Sr and Te) emitted from road traffic in both PM₁₀ and PM_2.5 mass. The ionic species concentration in PM₁₀ and PM_2.5 mass consists of 47-65% of anions and 35-53% of cations with dominance of SO₄²⁻ ions. Comparison of the metallic and ionic species in PM₁₀ and PM_2.5 mass indicated the contributions from sea and crustal soil emissions to the coarse particles and traffic emissions to fine particles.     

Numerical simulation of hydraulic fracturing and associatedmicroseismicity using finite-discrete element method

Hydraulic fracturing （HF） technique has been extensively used for the exploitation of unconventional oiland gas reservoirs. HF enhances the connectivity of less permeable oil and gas-bearing rock formationsby fluid injection, which creates an interconnected fracture network and increases the hydrocarbonproduction. Meanwhile, microseismic （MS） monitoring is one of the most effective approaches to evaluatesuch stimulation process. In this paper, the combined finite-discrete element method （FDEM） isadopted to numerically simulate HF and associated MS. Several post-processing tools, includingfrequency-magnitude distribution （b-value）, fractal dimension （D-value）, and seismic events clustering,are utilized to interpret numerical results. A non-parametric clustering algorithm designed specificallyfor FDEM is used to reduce the mesh dependency and extract more realistic seismic information.Simulation results indicated that at the local scale, the HF process tends to propagate following the rockmass discontinuities; while at the reservoir scale, it tends to develop in the direction parallel to themaximum in-situ stress.
2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.     

Chemical compositions and source identification of PM₂.₅ aerosols for estimation of a diesel source surrogate

Exposure to traffic-related pollution during childhood has been associated with asthma exacerbation, and asthma incidence. The objective of the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) is to determine if the development of allergic and respiratory disease is associated with exposure to diesel engine exhaust particles. A detailed receptor model analyses was undertaken by applying positive matrix factorization (PMF) and UNMIX receptor models to two PM_2.5 data sets: one consisting of two carbon fractions and the other of eight temperature-resolved carbon fractions. Based on the source profiles resolved from the analyses, markers of traffic-related air pollution were estimated: the elemental carbon attributed to traffic (ECAT) and elemental carbon attributed to diesel vehicle emission (ECAD).Application of UNMIX to the two data sets generated four source factors: combustion related sulfate, traffic, metal processing and soil/crustal. The PMF application generated six source factors derived from analyzing two carbon fractions and seven factors from temperature-resolved eight carbon fractions. The source factors (with source contribution estimates by mass concentrations in parentheses) are: combustion sulfate (46.8%), vegetative burning (15.8%), secondary sulfate (12.9%), diesel vehicle emission (10.9%), metal processing (7.5%), gasoline vehicle emission (5.6%) and soil/crustal (0.7%). Diesel and gasoline vehicle emission sources were separated using eight temperature-resolved organic and elemental carbon fractions. Application of PMF to both datasets also differentiated the sulfate rich source from the vegetative burning source, which are combined in a single factor by UNMIX modeling. Calculated ECAT and ECAD values at different locations indicated that traffic source impacts depend on factors such as traffic volumes, meteorological parameters, and the mode of vehicle operation apart from the proximity of the sites to highways. The difference in ECAT and ECAD, however, was less than one standard deviation. Thus, a cost benefit consideration should be used when deciding on the benefits of an eight or two carbon approach.     

A parameterization of dust concentration (PM₁₀) of dust events observed at Erdene in Mongolia using the monitored tower data

Hourly mean time series of dust concentration (PM₁₀) measured at 3 m high and a sonic-anemometer measured momentum and kinematic heat fluxes at 8 m high above the surface have been obtained from a 20-m monitoring tower located at Erdene in the Asian dust source region of Mongolia for years of 2009 and 2010. These time series were used to identify dust events and to develop optimal regression equations for the dust concentration of dust events with the friction velocity (u_*) and the convective velocity scale (w_*). In total, 68 dust events were identified in 2009 (except for November) and 43 dust events for the period from March to August in 2010. The duration of each dust event ranged from 3-29 h in 2009 and 5-35 h in 2010. The maximum hourly mean dust concentration of the dust event was found to be 4,107 μg m^− 3 in May in 2009 and 4,708 μg m^− 3 in March in 2010 while a minimum of 251 μg m^− 3 in August in 2009 and 662 μg m^− 3 in June in 2010. The optimal regression equation for the dust concentration (C) of dust events was found to have the form of log C = a + b(u_* + cw_*)ⁿ, where a, b, c and n are constants that vary month to month. The convective velocity scale (w_*) that has not been taken into account in most dust modelings was found to enhance the dust concentration of dust events during the cold period from December to March when the soil temperature was below the freezing level for both the stable (w_* < 0) and unstable (w_* > 0) stratifications, whereas the convective velocity caused a reduction in the dust concentrations during the warm period from April to October, suggesting the importance of the convective velocity to estimate dust concentration of dust events.     

Performance,emission and combustion characteristics of a single cylinder spark ignition engine using ethanol–petrol-blended fuels

The performance, exhaust emission and combustion analyses of a single cylinder spark ignition engine fuelled with extended range of ethanol–petrol blends were carried out successfully at full load conditions. Ethanol produced from raffia trunks was blended with petrol at different proportions by volume. In order to establish a baseline for comparison, the engine was first run on neat petrol. The engine performance parameters (engine torque, brake power, brake specific fuel consumption, brake mean effective pressure and brake thermal efficiency), exhaust emission parameters (CO, HC, CO₂ and O₂ emissions) and combustion parameters were determined for each blend of fuel at different engine speeds. The test results interestingly revealed that the addition of ethanol to petrol causes an improvement in combustion characteristics and significant reduction in exhaust emissions which in turn improved engine performance. In all, ethanol and its blends with petrol exhibited performance characteristics trends similar to that of petrol thus confirming them as suitable alternative fuels for spark ignition engines.     

Mechanism of kaolinite and titanium dioxide flocculation using chitosan--assistance by fulvic acids?

Flocculation of kaolinite using chitosan alone as flocculant has been reported to be difficult. Detailed investigations in our laboratory have shown that kaolinite can be easily removed from aqueous suspensions by flocculation and settling using chitosan, provided the suspension medium contains traces of dissolved humic substances. The flocculation is also extremely sensitive to the pH of the suspension. Removal of suspended titanium dioxide particles in water by flocculation using chitosan in presence of humic acids is also reported for the first time. A plausible mechanism explaining these observations is proposed in this paper.     

Parameter extraction of solar photovoltaic cells and modules using current–voltage characteristics

ABSTRACT

The significance of bio-inspired evolutionary algorithms has attracted many applications for obtaining best solutions to their optimisation problems in the past decades. This paper is about the application of one of these algorithms, namely, quantum particle swarm optimisation algorithm for parameter extraction of solar photovoltaic cells using current–voltage (I–V) characteristics. This algorithm has been used here to extract five parameters, namely, photocurrent, saturation current, series resistance, shunt resistance and ideality factor that influence the I–V relationship of single diode model solar photovoltaic cells. This approach has been validated for a cell and a module. Simulations using Matlab software have shown that the simulated I–V characteristics obtained using the extracted parameters have good agreement with the experimental I–V values. The reason for the interest taken in undertaking this work is to suggest a good and an accurate simulator for solar system designers.     

Investigating norovirus removal by microfiltration,ultrafiltration, and precoagulation–microfiltration processes using recombinant norovirus virus-like particles and real-time immuno-PCR

The removal of microorganisms by drinking water treatment processes has been widely investigated in laboratory-scale experiments using artificially propagated microorganisms. However, this approach cannot be applied to norovirus removal, because this virus does not grow in cell or organ culture, and this fact has hampered our ability to investigate its behavior during drinking water treatment. To overcome this difficulty, our research group previously used recombinant norovirus virus-like particles (rNV-VLPs), which consist of an artificially expressed norovirus capsid protein, in laboratory-scale drinking water treatment experiments. However, the enzyme-linked immunosorbent assay (ELISA) method generally used to detect rNV-VLPs is not sensitive enough to evaluate high removal ratios such as those obtained by ultrafiltration (UF). We therefore developed and applied a real-time immuno-polymerase chain reaction (iPCR) assay for rNV-VLP quantification to investigate norovirus removal by microfiltration (MF), UF, and hybrid precoagulation–MF processes. The rNV-VLP detection limit with the developed iPCR assay was improved at least 1000-fold compared with ELISA. Whereas MF with a nominal pore size of 0.1 μm could not eliminate NV-VLPs, a 4-log reduction was achieved by UF with a molecular weight cutoff of 1 kDa. When MF was combined with precoagulation (≥10 μmol-Fe/L for ferric chloride; ≥20 μmol-Al/L for polyaluminum chloride; ≥40 μmol-Al/L for alum), the performance of the hybrid process in eliminating rNV-VLPs was greater than that achieved by the 1 kDa UF. For all processes, the removal ratios of the bacteriophages MS2 and Qβ were greater than the rNV-VLP removal ratios by 1–2 logs, so neither bacteriophage can be recommended as a possible conservative surrogate for predicting the behavior of native NV during these processes.     

Corporate Capital and the Techniques of Modernity—Problems in the Mass Production of Space,Image, and Experience

This article seeks to accomplish two tasks. The first is to employ a materialist approach to the study of architecture that emphasizes the nature of practice as a set of techniques within history, rather than emphasizing the form of the finished work. The second task is to study the implications of the corporate franchise for the practice of architecture and for the landscape and to argue that this particular device has participated in the establishment of a new category of architectural production, that is, a mass production of architecture. The article also suggests that such mass production has created a new physical context—accessible networks of accommodation—that serves to fulfill a vision of the United States as a complex, integrated market.     

Maintenance and management of civil infrastructure based on condition,safety, optimization,and life-cycle cost∗

Cost-competent maintenance and management of civil infrastructure requires balanced consideration of both the structure performance and the total cost accrued over the entire life-cycle. Most existing maintenance and management systems are developed on the basis of life-cycle cost minimization only. The single maintenance and management solution thus obtained, however, does not necessarily result in satisfactory long-term structure performance. Another concern is that the structure performance is usually described by the visual inspection-based structure condition states. The actual structure safety level, however, has not been explicitly or adequately considered in determining maintenance management decisions. This paper reviews the recent development of life-cycle maintenance and management planning for deteriorating civil infrastructure with emphasis on bridges using optimization techniques and considering simultaneously multiple and often competing criteria in terms of condition, safety and life-cycle cost. This multiple-objective approach leads to a large pool of alternative maintenance and management solutions that helps active decision-making by choosing a compromise solution of preferably balancing structure performance and life-cycle cost.     

Scale,Site Selection and Function of Economic and Technological Development Zones

This article analyses different characteristics of scale,site selection and function of the current economic andtehnological development zones in our country.It further proposes that it is inappropriate for the economic andtechnological development zones to follow the“pattern of the special zones”,but a new pattern of“small scale,unitaryfunction and closeness to old city”should be adopted to fit in with the practical conditions in our country.The scale,landuse structure and the relations between the development zone and the old city are the basic issues in planning forthe development zones.These three essential elements constitute the pattern of planning which determines to a certainextent the success or failure of the development zones.     

Does the presence of desert dust modify the effect of PM10 on mortality in Athens, Greece?

Recent reports investigate whether windblown desert dust may exacerbate the short-term health effects associated with particulate pollution in urban centers. We have tested this hypothesis by using daily air pollution and mortality data for Athens, Greece during the period 2001-2006.We investigated the effects of exposure to particulate matter with aerodynamic diameter < 0 μg/m³ (PM₁₀) on total and cause specific mortality, during days with and without windblown desert dust, for all ages, stratified by age groups and by sex. We identified 141 dust days between 2001 and 2006. We used Poisson regression models with penalized splines to control for possible confounding by season, meteorology, day of the week and holiday effect.A 10 μg/m³ increase in PM₁₀ was associated with a 0.71% (95% confidence interval (CI): 0.42% to 0.99%) increase in all deaths. The effects for total and cause specific mortality were greater for those ≥ 75 years of age, while for total mortality higher effects were observed among females. The main effect of desert dust days and its interaction with PM₁₀ concentrations were significant in all cases except for respiratory mortality and cardiovascular mortality among those < 75 years. The negative interaction pointed towards lower particle effects on mortality during dust events.We found evidence of modification of the adverse health effects of PM₁₀ on mortality in Athens, Greece with desert dust events: the particle effects were significantly higher during non-desert dust days. Our analyses indicate that traffic related particles, which prevail on non-desert dust days, have more toxic effects than the ones originating from long-range transport, such as Sahara dust.     

Power quality analysis of 6 kW building-integrated photovoltaic system and economic evaluation using RETScreen™

This paper describes the power quality analysis applied on 6?kW building-integrated photovoltaic system (BIPVS) and its economic study. A monitoring system was implemented using virtual instrumentation to measure irradiance, ambient temperature and electric variables of the photovoltaic (PV) system. The study includes a period of one year from September 2015 to August 2016 and for this the IEEE 929-2000 standard guidelines were followed. The results indicate that the power quality parameters: % THDv, frequency, nominal voltage and flicker meet the standard limits mentioned. Economic analysis of the PV system using the RETScreen? software is also presented. The results show a net present value of USD 35,157 for a period of 20 years with an annual energy saving of USD 1750. Greenhouse gas emissions avoided by the use of solar energy are 6.6 t CO₂ per year.     

Prediction of engine performance and exhaust emissions with different proportions of ethanol–gasoline blends using artificial neural networks

The main purpose of this study is to experimentally investigate the use of ANNs (artificial neural networks) modelling to predict engine power, torque and exhaust emissions of a spark ignition engine which operates with gasoline and methanol blends. For the ANN modelling, the standard back-propagation algorithm was found to be the optimal choice for training the model. Afterwards, the performance of the ANN predictions was evaluated with the experimental results by comparing the predictions. Fuel type and engine speed have been used as the input layer, while engine torque, power, exhaust emissions, Tex and BSFC have also been used separately as the output layer. It was found that the ANN model is able to predict the engine performance, exhaust emissions, Tex and BSFC with a correlation coefficient of 0.9991887425, 0.9990868573, 0.9986749623, 0.9988624137, 0.9976761492, 0.9992943894 and 0.9978899033 for the Power, Torque, CO, CO₂, HC, Tex and BSFC for testing data, respectively.     

Accurate determination of Cd, Cr, Cu and Ni in woodlice and their skins--is moulting a means of detoxification?

Cd, Cr, Cu and Ni were determined in two different species of woodlice: Porcellio scaber and Porcellio dilatatus. Both P. scaber and P. dilatatus were cultivated under standardized conditions in a climatic chamber. Moreover, skins of the cultivated animals were collected and analysed separately to examine whether moulting is a way of detoxification from these elements. After drying and grinding both animal and skin samples, they were pooled to obtain enough sample material for each species. The pooled samples were digested in pure concentrated nitric acid using microwave-assisted high pressure digestion and, finally, analysed by ICP-OES. Special emphasis was given to quality control. To match the matrix of the samples very closely, the reference materials Dorm-2, Dogfish Muscle (Squalus acanthias) and SRM 1577b Bovine Liver were used to evaluate the whole analytical process including sample digestion. Analyses of the elements in the reference materials were carried out using three different wavelengths for each element simultaneously to check for spectral interferences and to select the wavelengths which were best suited for the analyses. Concentrations of Cd, Cr, Cu and Ni in woodlice and their skins indicated that moulting is a possible means of detoxification in the case of Cr and Ni.     

Figurations of spatiality and temporality in participatory design and after – networks,meshworks and patchworking

In recent years, many have combined actor–network theory (and after) and collective design. In this emerging field that we call participatory design and after, many have proposed and appropriated figurations such as networks, fluid, fire, thing and meshwork. In this paper, we argue that figurations do not only contribute to knowing the world, they also intervene in the becoming of worlds. This recognition of the performative character of figuration suggests that knowledge-making and world-making are inseparable, and makes it very important to be careful what figurations we imagine, articulate and use. In order to continue the work done in ANT and collective design that focuses on uncertainties, boundary-making, complexities and time, we propose the figuration of patchworking. What we particularly find generative with the figuration of patchworking is that it figures design as entanglements in multiple temporalities. Through the figuration of patchworking, we offer an approach that allows for understanding and working with multiple and overlapping collectives. This means to refigure how and where to draw the boundaries of co-designing in technological societies.     

Methylmercury in water, seston, and epiphyton of an Amazonian river and its floodplain, Tapajós River, Brazil

Levels and accumulation of MeHg were characterized in filtered water, suspended organo-mineral matter, phytoplankton, zooplankton and epiphyton during the dry season and the wet season. In open water of the lentic and lotic ecosystems, the MeHg in filtered water (< 0.2 microm) was near or below the detection limit (< 0.02-0.03 ng/l). These concentrations represent < 5% of the Hgtot. content in filtered water. Inundated forests (Igapó) and macrophyte floating mats were the only sites where MeHg was significantly detected (0.07-0.24 ng/l), representing 3-22% of the Hgtot. in filtered water. MeHg concentrations in organo-mineral suspended matter (2-26 ng/g dry wt. representing 0.6-7.3% of Hgtot.) were correlated with the N content but not with the C content. Data suggest that MeHg enrichment of suspended matter is strongly influenced by the presence of degraded planktonic remains relatively rich in N and MeHg. In zooplankton, MeHg concentrations (20-140 ng/g dry wt.) increased from the dry season to the end of the wet season. This increase was followed by higher proportions of MeHg during the wet season in comparison to the dry season (15-40 to 50-70% of the Hgtot.). The epiphytic material collected from the roots of macrophyte floating mats contained 2-8.5 ng/g dry wt. of MeHg. The proportion of MeHg to Hgtot. in epiphyton (1.5-8.3%) correlated with its C and N contents. The data suggest a greater bioavailability of MeHg in the Tapaj6s River ecosystems due to the seasonal increase in water level and the consequent inundation of the floodplain. Inundation favours the development of large macrophyte floating mats which increases the bioavailability of epiphyton to herbivorous/detritivorous fish. The root zone of floating macrophytes and the flooded organic horizon of the Igapó forest are the only sites along the Tapajós River where significant MeHg can be detected in the water column and sediment. This new study supports the hypothesis that MeHg production and transfer to the first link of the food chain in Amazonian river systems is closely related to organic matter biogeochemistry in the floodplain environment.