SYNTHESIS, CHARACHTERIZATION AND EVALUATION OF EXPANDABLE GRAPHITE BASED INTUMESCENT FIRE RETARDANT COATING FOR STEEL STRUCTURES

Structural steel is an integral part of any construction such as bridges, buildings, ships, cars and off shore structures. The integrity of structural steel has pivotal role in safety of structures and human. In the case of fire, the steel starts losing its load bearing ability above 500oC and in the case of fire, the temperature of unprotected steel rises to 800oC within 10 minutes. Intumescent fire retarding coatings are designed to insulate the structural steel under the action of heat, flames or fire thus protecting their integrity. The main objectives of this research project are to synthesis and characterization of an expandable graphite (EG) based intumescent coating formulation (ICF). An intumescent coating with considerable char expansion and flaky morphology can provide good heat shielding to the steel structures. A high residual weight of intumescent coating on exposure to fire forms a protective passive layer of char which can minimize the flow of heat to steel substrate. A range of formulations were synthesized by varying the concentration of intumescent ingredients. One formulation containing 8.5wt% expandable graphite was identified with char expansion 13.4 times. The performance of the ICF was optimized using a various particle size of EG. An ICF with 300m particle size improved char expansion, morphology, residual weight and reduced steel substrate temperature to 367oC after 60 minutes fire test. IFC formulation containing 300m was further studied for reinforcing inorganic fillers, Multi-walled carbon nanotubes (MWCNTs), Kaolin clay (KC) and Zirconium silicate (ZS). One formulation containing 5wt% ZS showed 24 times char expansion and residual weight was increased to 38% with respect to IF5-BA-Mel. The substrate temperature was reduced to 213°C and char was hard and adherent with substrate. Carbolite furnace was used to study the char expansion of intumescent coating formulations at 500oC and 800oC. Heat shielding test was performed according to ASTM E119 standard test. The test was conducted for 60 minutes and the temperature of the steel substrate was recorded at an interval of one minute. Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FESEM) were used to study the char morphology. Thermal stability of IFCs was analysed using Thermogravimetric analysis (TGA) and Differential thermal analysis (DTA). The chemical composition of residual char was determined using X-Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-Ray Photoelectron spectroscopy (XPS). The weather resistance of IFCs was measured using Q-Sun Xenon Test Chambers. The gaseous products during burning of coating samples were analyzed by Pyrolysis Gas Chromatography (Py-GC). The examination of char morphology showed that flaky and multiporous type of char is most suitable to reduce the flow of heat to steel substrate. It was also noted that addition of ZS 5wt% in ICF modified the char morphology from flaky to multiporous and this was very helpful to minimize substrate temperature. XRD analysis of char of IFCs showed that the presence of high temperature boron based compounds i.e. borophosphate, boron oxide and borophosphate oxide which are stable at high temperature and helped to reduce the flow of heat to substrate. The presence of these compounds in the char was also confirmed by functional groups analysis using FTIR. The elemental analysis and carbon contents of selected ICFs showed high carbon contents compared to oxygen. This type of char is suitable for formation of carboneous layer on the substrate surface. TGA analysis showed a considerable increase in residual weight of IF5-BA-Mel reinforced with inorganic fillers. Py-GC analysis of gaseous products released during burning of selected ICFs showed less concentration compared to IF5-BA-Mel formulation. The weathering test of selected ICFs showed approximately 2% decrease in char expansion, however no change in char morphology was observed. Based on the results it was concluded that a ICF containing 5wt% ZS is more suitable for long term application due to high char expansion, lower substrate temperature, high residual weight and environment friendly properties

Dentrification potential of different landuse types in an agricultural watershed, lower Mississippi valley.

Expansion of agricultural land and excessive nitrogen (N) fertilizer use in the Mississippi River watershed has resulted in a three-fold increase in the nitrate load of the river since the early 1950s. One way to reduce this nitrate load is to restore wetlands at suitable locations between croplands and receiving waters to remove run-off nitrate through previous termdenitrification.next term This research investigated previous termdenitrificationnext term potential (DP) of different land uses and its controlling factors in an agricultural watershed in the lower Mississippi valley (previous termLMV)next term to help identify sites with high DP for reducing run-off nitrate. Soil samples collected from seven land-use types of an agricultural watershed during spring, summer, fall and winter were incubated in the laboratory for DP determination. Low-elevation clay soils in wetlands exhibited 6.3 and 2.5 times greater DP compared to high-elevation silt loam and low-elevation clay soils in croplands, respectively. DP of vegetated-ditches was 1.3 and 4.2 times that of un-vegetated ditches and cultivated soils, respectively. Soil carbon and nitrogen availability, bulk density, and soil moisture significantly affected DP. These factors were significantly influenced in turn by landscape position and land-use type of the watershed. It is evident from these results that low-elevation, fine-textured soils under natural wetlands are the best locations for mediating nitrate loss from agricultural watersheds in the previous termLMV.next term Landscape position and land-use types can be used as indices for the assessment/modeling of previous termdenitrificationnext term potential and identification of sites for restoration for nitrate removal in agricultural watersheds

Economic Analysis of Tobacco Profitability in District Swabi

Economic profitability of production of tobacco in Swabi, KPK, Pakistan was investigated through the structured questionnaire and personal interview method during 2013 from five purposively selected villages. 65 sampled respondents were investigated during the study. Farm budgeting technique was applied to estimate cost, gross return and net revenue. Economic analysis revealed that the average cost was Rs. 348637.18 acre-1 with the average tobacco output estimate to be 3,244.73 kg acre-1 and average gross revenue of Rs. 430348.54 acre-1, whereas the average net revenue (net profit) was estimated to be Rs. 81711.36 acre-1. The regression analysis of profit function displays that cost, quantity of yield and price of the yield were the main factors of profit (net revenue) determination. Keywords: Tobacco;Net revenue;Cost of production; Regression

Denitrification and greenhouse gas emissions from cultivated and wetland alluvial soils

Agricultural development in the Mississippi River Basin has contributed to an 3-fold increase in NO3 loading of the river. Increased NO3 loading is a primary cause of eutrophication in the northern Gulf of Mexico. Identification of best management practices (BMPs) to reduce NO3 loss and wetlands restoration to remove NO3 through denitrification are critically needed. The objectives of this research were to determine factors controlling denitrification potential of different landscape units in an agricultural watershed and quantify the effects of BMPs and organic C amendments on denitrification rates of cultivated lands and restored forested wetlands. N2O, CH4 and CO2 emissions from restored and natural forested wetlands were measured to determine if restoration for NO3 removal will increase greenhouse gas emissions, thereby contributing to global warming and compromising the water quality benefits of restoration. Low-elevation, wetland clay soils exhibited 6.3 and 2.5 times greater denitrification potential than the high-elevation silt-loam and low-elevation clay soils under cultivation, respectively. Denitrification potentials of vegetated ditches were 1.3 to 4.2 times greater than the unvegetated ditches and cultivated soils, respectively. Soil cores collected from forested wetlands displayed 2.0 - 6.6 times greater denitrification rates than cultivated soils when incubated at 70 to 100% water-filled pore space (WFPS). Significantly lower N2O:N2 emission ratios were observed from wetlands than from cultivated soils. Denitrification rates in the cultivated and restored forested wetland soils increased 200% and 42%, respectively, when amended with cotton gin trash (CGT). BMPs increased denitrification rates of restored wetlands. Nitrate addition to forested wetlands led to a 48% increase in N2O emissions. Forested wetlands exhibited net CH4 sink of 438-1050 g CH4 ha-1 y-1. CO2 emission decreased as WFPS increased from 40 to100% in forested wetlands. Low-elevation clay soils in agricultural watersheds are the best candidates for wetland restoration for water quality improvement. CGT amendment of cultivated and restored soils in conjunction with BMPs can help reduce on-site NO3 loss. Wetland restoration in the Lower Mississippi valley will not significantly affect the global greenhouse gas emissions budget; however, increased N2O emissions due to NO3 additions merit consideration when establishing CO2 storage credits on restored wetlands

Economic Assessment of the Poverty-Environmrental Quality Nexus: A Case Study of Malakand Division

Poverty is blame to be one of the major cause and effect of environmental degradation/Deforestation. This bi-directional relationship is seems to be existing in the rural communities all over the world in a little bit stronger form. This study was conducted to find out the empirical relationship of rural poverty and Deforestation in Malakand division of Khyber Pakhtunkhwa province. The study was under taken by collecting primary data from 180 respondents randomly selected from all the seven districts of the division concerned. A well structured questionnaire was used for data collection comprising the questions regarding personal details, economic details, natural resource dependence, extent of forests degradation and poverty environment nexus etc. Non recursive two stage linear regression model was used for data analysis. The regression analysis was performed by statistical software SPSS Version 20. The result verified the existence of poverty and environmental degradation in the form of deforestation. The study indicates a key role of poverty in deforestation and vice versa. It was also concluded that rural community have low income level and depends mostly on forest resources for their basic needs and livelihood purposes. The study also indicates the severity of environmental degradation in the form of deforestation in the study area and most of the people were found unaware of the knowledge and importance of environmental conservation