Biodegradable Chitosan Hydrogels for In Vitro Drug Release Studies of 5-Flurouracil an Anticancer Drug

Novel semi-interpenetrating network (semi-IPN) hydrogels based on biodegradable chitosan and poly(N-isopropylacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) were prepared by free radical addition polymerization. Fourier transform infrared spectra and scanning electron microscopy were used to characterize the semi-IPN hydrogels and the results showed that chitosan and poly(N-isopropylacrylamide-co-2-acrylamide-2-methyl-1-propanesulfonic acid) semi-IPN hydrogels were coupled by the interaction of the functional groups present in NIPAAm, CS and AMPS units. The PNIPAAm and P(NIPAAm-AMPS)/CS hydrogels have lower critical solution temperature and the same was confirmed with the help of differential scanning calorimetry as well as with the temperature dependent swelling curves. The model anti cancer drug, 5-fluorouracil (5-FU) was loaded into the semi-IPN hydrogels, at ambient temperature. The 5-FU loading capacity and release behaviour were investigated with these hydrogels acting as carriers for controlled release. The released 5-FU concentration was calculated with the help of UV spectrophotometer at 266.5?nm.     

STEPPED WEIR ON AN ANISOTROPIC DRAINED STRATUM OF FINITE DEPTH1

Using Schwarz-Christoffel transformation, an analysis is presented for finding the pressure distribution and exit gradients for a weir on an anisotropic drained stratum.     

Effect of hydrogen addition on performance,emission, and combustion characteristics of Deccan hemp oil and its methyl ester–fuelled CI engine

Environmental Science and Pollution Research - A vegetable oil–fueled diesel engine operation is characterized by low brake thermal efficiency and relatively high smoke emission. Conversion...     

Need for adaptation strategy against global sea level rise: an example from Saudi coast of Arabian gulf

This paper reports sea level rise (SLR) scenarios causing land loss, environmental degradation and destruction of infrastructure in the Saudi coast of the Arabian Gulf. Human development structures such as, sea ports, desalination plants, industrial establishments, commercial buildings, fish farms etc. will be impacted, leading to great economic losses. A systematic analysis on the current environmental setting of east coast of Kingdom of Saudi Arabia (KSA) versus the existing infrastructure assets indicates that a 1?m sea level rise in Arabian Gulf affects approximately 650?km² land area, along the Saudi coastline of ~1,800?km in 1:50,000 scale. Three simulation scenarios were created with respect to 1?m, 2?m and 3?m rises from the present mean sea level and its impacts were assessed. Maps depicting major infrastructure assets, ecologically sensitive elements, historical locations, anthropogenic zones, and Environmental Sensitivity Indices (ESI) were used for overlaying the sea level change map, in a Geographic Information System (GIS) platform. In general, the Jubail Marine Park area will have serious impact due to SLR. The inundation of low?Clying lands will affect the mangroves species of Dawhat Ad Dafi, coral reefs, coastal salt marshes, groundwater aquifers, and fish stocks. The risk of inundation on the Abu Ali Island, given their status as marine sanctuary of international importance, is particularly high. As an adaptation strategy, it is proposed that the KSA should implement Integrated Coastal Zone Management Plan (ICZMP) for the Arabian Gulf coast without further delay for the protection of its vulnerable resources and for sustainable development.     

Monitoring and assessment of groundwater quality in a khondalitic terrain,Andhra Pradesh,India

The groundwater quality assessment for the drinking and irrigation purpose is carried out in the Kandivalasa River Sub Basin covered with khondalitic suite (Garneti ferrous, Sillimanite, Gneiss) of rocks, near Cheepurupalli town of Vizianagaram district, Andhra Pradesh, India. The analysis for the groundwater quality for drinking has shown the slightly alkaline nature and high values of alkalinity in the study area. A very high concentration of total dissolved solids value is observed at one pocket where there has been contamination by many fertilizer industries located nearby the study area. The groundwater is highly affected by the nitrate. Higher fluoride values are obtained at few pockets. Most of the samples in the study area are categorized as very hard category. According to the Piper trilinear diagram, it can be observed that the carbonate hardness and secondary salinity have occupied at major part of study area. From the analysis of sodium adsorption ratio, salinity hazard, sodium percentage, residual sodium carbonate, and Kelly’s ratio, all the groundwater samples except at few locations fell under the category of good to excellent for irrigation. The prepared integrated groundwater quality maps for the drinking purpose and agricultural purposes are indicating that, by and large, the low-lying areas are having poor groundwater quality than the uplands for drinking as well as agricultural needs which means that the groundwater quality of the basin is following the topography.     

INTERFACE BETWEEN TWO DISSIMILAR FLUIDS BENEATH A SHEETPILE COFFERDAM1

ABSTRACT: A closed form solution is presented for determining the shape and location of the interface between two dissimilar fluids (having different densities) when steady flow takes place through a homogeneous and isotropic porous medium, into a sheetpile cofferdam; the interface is assumed to be sharp and the lower fluid stationary. The solution is obtained using the inverse hodograph. Numerical results are presented in nondimensional form for various parametric conditions in the physical plane; the interface pattern, as also the seepage discharge and exit gradient distribution are shown. The critical conditions of the interface are studied.     

Column dynamic studies and breakthrough curve analysis for Cd(II) and Cu(II) ions adsorption onto palm oil boiler mill fly ash (POFA)

This paper investigates the adsorption characteristics of palm oil boiler mill fly ash (POFA) derived from an agricultural waste material in removing Cd(II) and Cu(II) from aqueous solution via column studies. The performance of the study is described through the breakthrough curves concept under relevant operating conditions such as column bed depths (1, 1.5, and 2 cm) and influent metal concentrations (5, 10, and 20 mg/L). The Cd(II) and Cu(II) uptake mechanism is particularly bed depth- and concentration-dependant, favoring higher bed depth and lower influent metal concentration. The highest bed capacity of 34.91 mg Cd(II)/g and 21.93 mg Cu(II)/g of POFA was achieved at 20 mg/L of influent metal concentrations, column bed depth of 2 cm, and flow rate of 5 mL/min. The whole breakthrough curve simulation for both metal ions were best described using the Thomas and Yoon–Nelson models, but it is apparent that the initial region of the breakthrough for Cd(II) was better described using the BDST model. The results illustrate that POFA could be utilized effectively for the removal of Cd(II) and Cu(II) ions from aqueous solution in a fixed-bed column system.     

Phytoremediation and long-term site management of soil contaminated with pentachlorophenol (PCP) and heavy metals

Pentachlorophenol (PCP) is a persistent organic pollutant (POP) previously used as a timber treatment chemical to prevent sap stain and wood rot. Commonly used in wood treatment industries for the last 50 years, there are now many sites worldwide that are contaminated with PCP. Although persistent, PCP is a mobile contaminant and therefore has a propensity to leach and contaminate surrounding environments. Both willow (Salix sp., 'Tangoio') and poplar (Populus sp. 'Kawa') growing in an open-ended plastic greenhouse were found to tolerate soil PCP concentrations of 250 mg kg(-1) or less and both species stimulated a significant increase in soil microbial activity when compared to unplanted controls. Both poplar and willow could not survive PCP concentrations above 250 mg kg(-1) in soil. Pentachlorophenol degradation occurred in both planted and unplanted pots, but a higher rate of degradation was observed in the planted pots. Soil contaminated by wood-treatment activities often contains co-contaminants such as B, Cr, Cu and As, that are also used as timber preservatives. An additional column leaching experiment, done along side the potted trial, found that PCP, B, Cr, Cu and As were all present in the column leachate. This indicates that although Cu, Cr and As are generally considered immobile in the soil, they were mobilised under our column conditions. If a contaminated site were to be hydraulically 'sealed' using plants, a reticulation irrigation system should be installed to capture any contaminant leachate resulting from heavy rains. This captured leachate can either be independently treated, or reapplied to the site. Our data demonstrate a reduction in soil hydraulic conductivity with repeated application of leachate containing PCP and metal compounds but the soil did not become anaerobic. This would need to be considered in site remediation design.     

Potential of Rhizobacteria for Improving Lead Phytoextraction in Ricinus communis

Heavy metal–resistant bacterial strains were isolated from heavy metal–contaminated soils and identified as Bacillus sp. and Leclercia adecarboxylata on the basis of their morphology and biochemical characters using the VITEK 2 Systems Version 05.02. The heavy metal and antibiotic resistance of the isolates were studied. A green house pot experiment was conducted to examine the bacterial ability to extract the lead in soils and for their effect on lead uptake by Ricinus communis in an artificially contaminated soil. Bacterial inoculated pots increased the biomass of the R. communis compared to the uninoculated control, and the root growth of the plant was also increased in the inoculated pot. The experimental data confirmed that lead‐resistant bacteria have a pronounced effect on heavy metal uptake in plants, which may provide a new bacterially assisted phytoremediation of metal‐contaminated soils. © 2013 Wiley Periodicals, Inc.