570 research outputs found

    Single door approach for planning, implementation and operation of rural WATSAN projects in Nepal

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    Too many stakeholders (e.g. Governmental and Non-Governmental Organisations, Donor Agencies, and Private Sectors) are involved in rural Water Supply and Sanitation (WATSAN) sector, and are currently executing projects in their own approach and modality which is easier and comfortable to them. The lack of single approach has not only brought confusion among recipient communities but also created managerial dilemma among various stakeholders. Therefore, in order to make a well established single approach in rural WATSAN sector, Department of Local Infrastructure Development and Agricultural Roads (DoLIDAR) has taken initiative. Thereto, DoLIDAR prepared an outline of the approach which was then revised by the centre level consultative meeting of major rural WATSAN stakeholders. Regional level workshops were also organized to collects comments/suggestion/aspirations from different stakeholders. The single approach thus prepared and endorsed by all stakeholders will be a milestone towards moving to Sector Wide Approach (SWAp) in rural WATSAN sector in Nepal

    Butorphanol in Labour Analgesia

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    Introduction: Labour is the process where uterine contractions lead to expulsion of product of conception through the vagina into the outer world. Labour pain is one of the most severe pains which has ever been evaluated and its fear is one of the reasons women wouldn’t go for natural delivery. Delivery is a painful experience for all of the women except a few of them. The labor pain results from some physiological-psychological causes. Different pharmacological and non-pharmacological methods have been tried for pain relief in labour. The objective of this study is to see the effect of butorphanol injection in labour pain. Methods: It is a descriptive cross-sectional study conducted in B.P. Koirala institute of health sciences. We observed 200 pregnant women meeting the inclusion criteria and giving the informed consent who were on 1 mg butorphanol i.m. at the onset of active stage of labour every 4 hourly and on demand. Pain assessment was done by Numerical Pain analogue scale measured from 1 to 10. Fetal heart rate monitoring was done according to the hospital protocol. Caesarean section was performed for obstetrical indication. Neonatal outcome was evaluated by on duty pediatrician and APGAR score were noted at 1 and 5 min. Results: The pain scores in first, second, third, fourth hour were (8.83±0.773), (9.84±0.544), (9.94±0.338), (9.6±0.298) respectively, where 1st and 2nd hour is statistically significant. Conclusions: Butorphanol is an effective labour analgesia without significant adverse effects on women and the neonatal outcome

    Influence of Solution Chemistry on the Deposition and Detachment Kinetics of a CdTe Quantum Dot Examined Using a Quartz Crystal Microbalance

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    Nanoscale zerovalent iron (NZVI) particles are often coated with polymeric surface modifiers for improved colloidal stability and transport during remediation of contaminated aquifers. Doping the NZVI surface with palladium (Pd-NZVI) increases its reactivity to pollutants such as trichloroethylene (TCE). In this study, we investigate the effects of coating Pd-NZVI with two surface modifiers of very different molecular size: rhamnolipid (RL, anionic biosurfactant, M.W. 600 g mol–1) and carboxymethylcellulose (CMC, anionic polyelectrolyte, M.W. 700 000 g mol–1) on TCE degradation. RL loadings of 13–133 mg TOC/g NZVI inhibited deposition of Pd in a concentration-dependent manner, thus limiting the number of available Pd sites and decreasing the TCE degradation reaction rate constant from 0.191 h–1 to 0.027 h–1. Furthermore, the presence of RL in solution had an additional inhibitory effect on the reactivity of Pd-NZVI by interacting with the exposed Pd deposits after they were formed. In contrast, CMC had no effect on reactivity at loadings up to 167 mg TOC/g NZVI. There was a lack of correlation between Pd-NZVI aggregate sizes and TCE reaction rates, and is explained by cryo-transmission electron microscopy images that show open, porous aggregate structures where TCE would be able to easily access Pd sites

    Reduced transport potential of a palladium-doped zero valent iron nanoparticle in a water saturated loamy sand

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    Direct in situ injection of palladium-doped nanosized zero valent iron (Pd-NZVI) particles can contribute to remediation of various environmental contaminants. A major challenge encountered is rapid aggregation of Pd-NZVI and hence very limited mobility. To reduce aggregation and concurrently improve particle mobility, the surface of bare Pd-NZVI can be modified with stabilizing surface modifiers. Selected surface-modified Pd-NZVI has shown dramatically improved stability and transport. However, little is known regarding the effects of aquifer grain geochemical heterogeneity on the transport and deposition behavior of surface-modified Pd-NZVI. Herein, the mobility of surface stabilized Pd-NZVI in two granular matrices representative of model ground water environments (quartz sand and loamy sand) was assessed over a wide range of environmentally relevant ionic strengths (IS). Carboxymethyl cellulose (CMC), soybean flour and rhamnolipid biosurfactant were used as Pd-NZVI surface modifiers. Our results show that, both in quartz sand and loamy sand, an increase in solution IS results in reduced Pd-NZVI transport. Moreover, at a given water chemistry, Pd-NZVI transport is notably attenuated in loamy sand implying that geochemical heterogeneity associated with loamy sand is a key factor influencing Pd-NZVI transport potential. Experiments conducted at a higher Pd-NZVI particle concentration, to be more representative of field conditions, show that rhamnolipid and CMC are effective stabilizing agents even when 1 g/L Pd-NZVI is injected into quartz sand. Overall, this study emphasizes the extent to which variation in groundwater chemistry, coupled with changes in aquifer geochemistry, could dramatically alter the transport potential of Pd-NZVI in the subsurface environment

    Rhamnolipid Biosurfactant and Soy Protein Act as Effective Stabilizers in the Aggregation and Transport of Palladium-Doped Zerovalent Iron Nanoparticles in Saturated Porous Media

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    Palladium-doped nanosized zerovalent iron (Pd-NZVI) particles can contribute to the transformation of chlorinated solvents and various other contaminants into innocuous products. To make Pd-NZVI an effective in situ subsurface remediation agent, these particles need to migrate through a targeted contaminated area. However, previous studies have reported very limited mobility of these particles in the groundwater environment and attributed it to rapid aggregation and subsequent pore plugging. In this study, we systematically investigated the influence of selected natural and nontoxic organic macromolecules (carboxymethyl cellulose, rhamnolipid biosurfactants, and soy protein) on the aggregation and transport behavior of bare and coated Pd-NZVI. Aggregation behavior was investigated using dynamic light scattering by monitoring the evolution of hydrodynamic diameter as a function of time, whereas transport behavior was investigated by conducting water-saturated sand-packed column experiments. While bare Pd-NZVI is prone to rapid aggregation, we observed good colloidal stability and concurrent enhanced transport of Pd-NZVI coated with carboxymethyl cellulose, rhamnolipid biosurfactants, and soy protein. Each surface modifier performed well at lower ionic strength (IS) (10 mM NaHCO<sub>3</sub>), and one of the rhamnolipid surface modifiers (JBR215) significantly enhanced transport of 150 mg/L Pd-NZVI at concentrations as low as 10 mg/L total organic carbon. However, an increase in the solution IS induced significant Pd-NZVI aggregation with a simultaneous decrease in the transport potential in accordance with the DLVO (Derjaguin, Landau, Verwey, and Overbeek) theory of colloidal stability. Nonetheless, at the highest IS (300 mM NaHCO<sub>3</sub>) investigated, the mobility of rhamnolipid-coated Pd-NZVI is significantly higher than that of Pd-NZVI coated with the other surface modifiers, suggesting that biosurfactants may be the most suitable surface modifiers in field application. Overall, this study emphasizes how stabilization of Pd-NZVI with natural macromolecules such as rhamnolipids can improve the transport potential of these reactive nanoparticles in subsurface remediation applications at concentrations significantly lower than those of other commonly used polymers

    Using the Quartz Crystal Microbalance with Dissipation Monitoring to Evaluate the Size of Nanoparticles Deposited on Surfaces

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    A quartz crystal microbalance with dissipation (QCM-D) monitoring can be an alternative tool to characterize nanoparticle size by virtue of its acoustic principle to sense adsorbed mass. In this study, sizes obtained by QCM-D for polymer-coated metallic nanoparticles and polydisperse polystyrene latex particle suspensions were compared with those obtained by transmission electron microscopy (TEM) and dynamic light scattering (DLS). We describe the obtained “QCM-D mass”, which is weighted over surface area, by a general particle height distribution equation that can be used to determine the average particle diameter of a distribution of particles deposited on the QCM-D surface. Because the particle height distribution equation can be used for any particle geometry and surface packing geometry, it is described how the QCM-D can also be used to study the orientation of deposited nonspherical particles. Herein, the mean nanoparticle sizes obtained by QCM-D were generally in closer agreement with the primary particle size determined by TEM than with the sizes obtained by DLS, suggesting that primarily smaller particles within the particle population deposited on the sensor surface. Overall, the results from this study demonstrate that QCM-D could serve as an alternative and/or complementary means to characterize the size of nanoparticles deposited on a surface from suspensions of varying complexity

    International Journal of Biodiversity and Conservation

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    Farmers ’ dependency on forests for nutrients transfer to farmlands in mid-hills and high mountain regions in Nepal (case studies in Hemja, Kaski, Lete and Kunjo, Mustang district

    Effects of Rhamnolipid and Carboxymethylcellulose Coatings on Reactivity of Palladium-Doped Nanoscale Zerovalent Iron Particles

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    Nanoscale zerovalent iron (NZVI) particles are often coated with polymeric surface modifiers for improved colloidal stability and transport during remediation of contaminated aquifers. Doping the NZVI surface with palladium (Pd-NZVI) increases its reactivity to pollutants such as trichloroethylene (TCE). In this study, we investigate the effects of coating Pd-NZVI with two surface modifiers of very different molecular size: rhamnolipid (RL, anionic biosurfactant, M.W. 600 g mol<sup>–1</sup>) and carboxymethylcellulose (CMC, anionic polyelectrolyte, M.W. 700 000 g mol<sup>–1</sup>) on TCE degradation. RL loadings of 13–133 mg TOC/g NZVI inhibited deposition of Pd in a concentration-dependent manner, thus limiting the number of available Pd sites and decreasing the TCE degradation reaction rate constant from 0.191 h<sup>–1</sup> to 0.027 h<sup>–1</sup>. Furthermore, the presence of RL in solution had an additional inhibitory effect on the reactivity of Pd-NZVI by interacting with the exposed Pd deposits after they were formed. In contrast, CMC had no effect on reactivity at loadings up to 167 mg TOC/g NZVI. There was a lack of correlation between Pd-NZVI aggregate sizes and TCE reaction rates, and is explained by cryo-transmission electron microscopy images that show open, porous aggregate structures where TCE would be able to easily access Pd sites
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