Evaluation of catalyzed and electrically heated filters for removal of particulate emissions from diesel-A- and JP-8-fueled engines

In-service diesel engines are a significant source of particulate matter (PM) emissions, and they have been subjected to increasingly strict emissions standards. Consequently, the wide-scale use of some type of particulate filter is expected. This study evaluated the effect of an Engelhard catalyzed soot filter (CSF) and a Rypos electrically heated soot filter on the emissions from in-service diesel engines in terms of PM mass, black carbon concentration, particle-bound polycyclic aromatic hydrocarbon concentration, and size distribution. Both filters capture PM. The CSF relies on the engine's exhaust to reach the catalyst regeneration temperature and oxidize soot, whereas the electrically heated filter contains a heating element to oxidize soot. The filters were installed on several military diesel engines. Particle concentrations and compositions were measured before and after installation of the filter and again after several months of operation. Generally, the CSF removed at least 90% of total PM, and the removal efficiency improved or remained constant after several months of operation. In contrast, the electrical filters removed 44-69% of PM mass. In addition to evaluating the soot filters, the sampling team also compared the results of several real-time particle measurement instruments to traditional filter measurements of total mass.     

Geographic information systems (GIS) based model of dairy manure transportation and application with environmental quality consideration

Survey information was used to develop a minimum cost spatial dairy manure transportation model where environmental quality and crop nutrient requirements were treated as constraints. The GIS model incorporated land use types, exact locations of dairy farms and farmlands, road networks, and distances from each dairy farm to receiving farmlands to identify dairy manure transportation routes that minimized costs relative to environmental and other constraints. Our analyses indicated that the characteristics of dairy manure, its bulk and relatively low primary N, P₂O₅ and K₂O nutrient levels limit the distribution areas or distances between the farms and the land over which the manure can be economically spread. Physical properties of the land limit the quantities of nutrients that can be applied because of excess nutrient buildup in soil and potential to harm nearby waterbodies and downstream people and places. Longer distances between dairy and farmland favor the use of commercial fertilizers due to the high cost of manure transportation. At $0.08 per ton per km transportation cost, the optimal cut-off distances for dairy manure application is 30 km for N and 15 km each for P₂O₅ and K₂O consistent rules. An analysis of dairy manure application to different crop types suggest that, on average, 1 ha of land requires 61 tons of dairy manure to meet the recommended N, P₂O₅ and K₂O needs.     

Determinants of deforestation in Nepal's Central Development Region

The process of deforestation in the Central Development Region (CDR) of Nepal is diverse in space and time, with rapid deforestation still occurring in areas outside the national parks and wildlife reserves. This paper identifies the spatial driving forces (SDFs) of deforestation in the CDR for 1975–2000 using satellite data of 1975 (MSS), 1990 (TM), and 2000 (ETM+) along with socio-demographic and socioeconomic variables. Radiometrically calibrated satellite images are individually classified into seven distinct classes and merged together to cover the entire CDR. Classification accuracies are also assessed. Areas of land use and cover within the areas of each Village Development Committee (VDC) and municipality represented by GIS polygons are calculated from the classified images by overlaying vector files of 1845 polygons representing sections of VDCs and municipalities in 30–1199 m, 1200–2399 m, 2400–4999 m and >5000 m elevation levels. These elevation levels were estimated from the DEM compiled from 24 ASTER scenes taken on different dates. Only the first three elevation levels are used in the analysis because area >5000 m is under permanent snow cover where human related forestry activities are almost negligible. A transition matrix is generated for 1975–1990 using classified images of 1975 and 1990 and then this product is used to further develop another transition matrix for 1990–2000 with the classified ETM+ 2000 images as the final stage. The GIS polygon layer is overlaid on the transition matrices to calculate deforestation areas for 1975–1990 and 1990–2000. Biophysical and socioeconomic information collected from various sources is then brought into a GIS platform for statistical analyses. Six linear regression models are estimated using SAS; in effect, two models for each elevation range representing the 1975–1990 and 1990–2000 periods of change to identify SDF influences on deforestation. These regression analyses reveal that deforestation in the CDR is related to multiple factors, such as farming population, genders of various ages, migration, elevation, road, distance from road to forest, meandering and erosion of river, and most importantly the conversion of forestland into farmland.     

Synergism of MGK-264 and piperonyl butoxide on the toxicity of plant derive molluscicides

The binary mixture of ethanolic extract of powder, hecogenin, tigogenin, seed powder and thymol with synergiats MGK-264 and piperony butoxide in a 1:5 ratio were used against the . It was observed that the toxic effect of these mixtures were time and dose dependent. The binary mixtures of plant molluscicides with synergist were more toxic with respect to the independent toxicity of these plant molluscicides. Maximum synergistic action (10 fold) of MGK-264 and piperonyl butoxide was observed with hecogenin.     

Determinants of adaptation practices to climate change by Chepang households in the rural Mid-Hills of Nepal

This study analyzes the factors influencing the adoption of various adaptation practices by a highly marginalized indigenous community in the remote rural Mid-Hills of Nepal. The analysis is based on a household survey conducted among 221 Chepang households selected randomly. A multivariate probit model was used to analyze five categories of adaptation choices against a set of socio-economic, institutional, infrastructural, and perception variables. Perception of rainfall changes, size of landholding, status of land tenure, distance to motor road, access to productive credit, information, extension services, and skill development trainings are all influential to enable households to deviate away from traditional coping strategies and adopt suitable practices to adapt to climate vagaries. Policies and development activities should be geared to address these determinants in order to facilitate adaptation.     

Factors affecting the adoption of multiple climate‐smart agricultural practices in the Indo‐Gangetic Plains of India

Climate change poses a major threat to agricultural production and food security in India, and climate‐smart agriculture (CSA) is crucial in addressing the potential impacts. Using survey data from 1,267 farm households in 25 villages from Bihar and Haryana in the Indo‐Gangetic Plains, this study analyzes the factors that determine the probability and level of adoption of multiple CSA practices, including seeds of stress‐tolerant varieties, minimum tillage, laser land leveling, site‐specific nutrient management and crop diversification. We applied a multivariate probit model for the simultaneous multiple adoption decisions, and ordered probit models for assessing the factors affecting the level of adoption. The adoption of the various CSA practices is interrelated, whereas several factors, including household characteristics, plot characteristics, market access and major climate risks are found to affect the probability and level of CSA adoption. Climate‐smart agriculture (CSA) adoption and its intensity also vary significantly between eastern Bihar, which is relatively poor and densely populated, and north‐western Haryana. Engaging multiple stakeholders such as farmers, agricultural institutions, agricultural service providers and concerned government departments at the local level is crucial for the large‐scale uptake of CSA. The study, therefore, calls for agricultural policy reforms so that most of the issues related to the uptake of CSA can be adequately addressed.     

A Simple Framework for Incorporating Seasonal Streamflow Forecasts into Existing Water Resource Management Practices1

Gong, Gavin, Lucien Wang, Laura Condon, Alastair Shearman, and Upmanu Lall, 2010. A Simple Framework for Incorporating Seasonal Streamflow Forecasts Into Existing Water Resource Management Practices. Journal of the American Water Resources Association (JAWRA) 46(3):574-585. DOI: 10.1111/j.1752-1688.2010.00435.x Abstract: Climate-based streamflow forecasting, coupled with an adaptive reservoir operation policy, can potentially improve decisions by water suppliers and watershed stakeholders. However, water suppliers are often wary of straying too far from their current management practices, and prefer forecasts that can be incorporated into existing system modeling tools. This paper presents a simple framework for utilizing streamflow forecasts that works within an existing management structure. Climate predictors are used to develop seasonal inflow forecasts. These are used to specify operating rules that connect to the probability of future (end of season) reservoir states, rather than to the current storage, as is done now. By considering both current storage and anticipated inflow, the likelihood of meeting management goals can be improved. The upper Delaware River Basin in the northeastern United States is used to demonstrate the basic idea. Physically plausible climate-based forecasts of March-April reservoir inflow are developed. Existing simulation tools and rule curves for the system are used to convert the inflow forecasts to reservoir level forecasts. Operating policies are revised during the forecast period to release less water during forecasts of low reservoir level. Hindcast simulations demonstrate reductions of 1.6% in the number of drought emergency days, which is a key performance measure. Forecasts with different levels of skill are examined to explore their utility.     

Analysis of different nutrient status of liquid bio-fertilizer of different combinations of buffalo dung with gram bran and water hyacinth through vermicomposting by <Emphasis Type="Italic">Eisenia fetida</Emphasis>

The animal, agro-wastes and water hyacinth (Eichhornia crassipes) are a serious problem for the society and ecosystem. The present study carried out the management of water hyacinth and observation of nutritional status like pH, electrical conductivity (EC), total organic carbon (TOC), total Kjeldahl nitrogen (TKN), C/N ratio, total phosphorus and total calcium (TCa) of liquid bio-fertilizer (vermiwash) before and after vermicomposting of feed materials of different combinations of buffalo dung (BD) with water hyacinth (WH) and gram bran (GB). After vermicomposting of different combinations of BD with WH and agro-wastes, significant decrease in level of pH, EC, TOC and C/N ratio was observed, whereas significant increase in TKN, TK, TAP and TCa level in vermiwash of final vermicompost with respect to initial feed material was observed. The pH of initial mixture in all combinations has tended to basic in nature, while in final vermicompost, it becomes neutral/basic. The significant increase was observed in the level of TKN, TK, TAP in BD + GB + WH (1:2:1) and TCa in BD + GB + WH (1:1:2) vermiwash of final vermicompost of combination, whereas decrease was observed in TOC, C/N ratio, pH and EC in BD + WH (1:1), BD + GB + WH (1:1:1), BD + GB + WH (1:2:1) and BD + GB (1:1), respectively.     

Atmospheric particle-bound polycyclic aromatic compounds over two distinct sites in Pakistan: Characteristics, sources and health risk assessment

Much attention is drawn to polycyclic aromatic hydrocarbons（PAHs） as an air pollutant due to their toxic, mutagenic and carcinogenic properties. Therefore, to understand the levels, seasonality, sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan, total suspended particle（TSP） samples were collected for over one year period. The average total PAH concentrations were 31.5 ± 24.4 and 199 ± 229 ng/m³ in Karachi and Mardan, re...     

Evaluation of SWAT sub-daily runoff estimation at small agricultural watershed in Korea

A study was undertaken for the prediction of runoff flow from 0.8 ha field-sized agricultural watershed in South Korea using Soil and Water Assessment Tool (SWAT) sub-daily. The SWAT model with sub-daily configuration predicted flow from the watershed within the range of acceptable accuracy. The SWAT sub-daily simulations were carried out for a total of 18 rainfall events, 9 each for calibration and validation. Overall trend and extent of matching simulated flow for the rainfall events in 2007-2008 with measured data during the calibration process were coefficient of determination (R²) value of 0.88 and Nash and Sutcliffe Efficiency (E_NS) value of 0.88. For validation, R² and E_NS values were 0.9 and 0.84, respectively. Whereas R² and E_NS values for simulation results using daily rainfall data were 0.79 and -0.01, respectively, that were observed to be out of acceptable limits for the model simulation. The importance of higher time resolution (hourly) precipitation records for flow simulation were evaluated by comparing R² and E_NS with 15 min, 2 h, 6 h and 12 h precipitation data, which resulted in lower statistics with increases in time resolution of precipitation data. The SWAT sub-daily sensitivity analysis was performed with the consideration of hydraulic parameter and was found as in the rank order of CN2 (curve number), ESCO (soil evaporation compensation factor), GW_DELAY (ground water delay time), ALPHA_BF ( base flow alpha factor), GWQMN ( a threshold minimum depth of water in the shallow aquifer required for return flow to occur) , REVAPMN (minimum depth of water in shallow aquifer for re-evaporation to occur) , LAT_TIME (lateral flow travel time) respectively. These sensitive parameters were evaluated at 10% higher and lower values of the parameters, corresponding to 70.5% higher and 23.2% lower in simulated flow out from the SWAT model. From the results obtained in this study, hourly precipitation record for SWAT sub-daily with Green-Ampt infiltration method was proven to be efficient for runoff estimation at field sized watershed with higher accuracies that could be efficiently used to develop site-specific Best Management Practices (BMPs) considering rainfall intensity, rather than simply using daily rainfall data.