Solid Phase Extraction of Cd(II) from sample water by modified nano polyacrylonitrile fiber

Abstract: Modified nano polyacrylonitrile fiber (PANF) was prepared by adding of acrylic fibers to methanolamine (MMA) with different concentration solutions. The stability of a chemically modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of Modified nano polyacrylonitrile fiber. The application of this Modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cd(II) was found to exhibit the highest affinity towards extraction by these Modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for Cd(II) to occur by Modified nano polyacrylonitrile fiber. The potential applications of Modified nano polyacrylonitrile fiber for selective extraction of Cd(II) to occur from aqueous solution were successfully accomplished as well as pre-concentration of low concentration of Cd(II) (60 pg ml -1 ) from natural tap water with a pre-concentration factor of 100 for Cd(II) off-line analysis by flame atomic absorption analysis

Improvement Transient Stability of Fixed Speed Wind Energy Conversion System by Using Transformer-Type Superconducting Fault Current Limiter

International audienceThe wind turbine generation system (WTGS) is one of the representative renewable energy systems. With the rapid development of WTGS and its increased capacity, the level of short circuit current will increase in distribution systems. The application of the Superconducting Fault Current Limiter (SFCL), would not only reduce the level of the short circuit current but also offer a reliable interconnection to the network. The transformer-type superconducting fault current limiter (SFCL) is one of the fault current limiters, and has many advantages such as design flexibility. In this paper, the effect of transformer-type SFCL on transient behavior of grid connected to WTGS is studied. The WTGS is considered as a fixed-speed system, equipped with a squirrel-cage induction generator. The drive-train is represented by two-mass model. The simulation results show that the transformer-type SFCL not only limits the fault current but also can improve the dynamic performance of the WTGS

Borohydride Reduction of Cobalt Oxide (Co3O4) Nanoparticles

Recently, magnetic nanomaterials have been used in a wide range of applications such as medicine and electronics. In this research, rod-like shaped cobalt oxide magnetic nanoparticles (Co3O4) were synthesized by a simple co-precipitation method using cobalt chloride as a precursor and sodium borohydride (NaBH4) as reducing agent. Their structural and surface morphological properties were characterized by high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and vibration sampling magnetometer with (VSM). XRD measurement exhibited the structure of Co3O4 nanocrystals for annealed samples. The TEM results showed the cobalt oxide nanoparticles with good uniformity in the range size of 10-40 nm. The SEM images revealed that the particles changed from spherical shape to rod-like shape with increasing temperature. Magnetic measurements showed the coercive field of around 84.5G and saturation magnetization of annealed of around 9.83 emu/g

Effects of Presence of Waves on Shallow Estuaries Hydrodynamics

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Fabrication of Mesoporous Silica-coated Graphene Oxide by New Method and Application in Solid Phase Extraction for Preconcentration of Cu2+

Graphene oxide is a derivates of graphene that has a ultrahigh specific surface space with variety of chemically reactive functionalities, such as epoxy and hydroxyl groups on the basal plane and carboxylic acid groups along the area edge, which can be use different groups for functionalization, consequentlyit has a great promise for use as sorbent materials. On the other hand silica is well-known one of the best sorbent for adsorption that we use it as substance for coated on the graphene oxide for produce an ultra-sensitive sorbent. A new technique using a solid phase extraction (SPE) cartridge with graphene oxide functionalized by silica as sorbent was developed for the preconcentration of trace amounts of copper and was determined by flame atomic absorption spectrometry (FAAS). Some of the important parameters were selected and optimized. Under the optimized conditions the limit of detection (LOD) and limit of quantification (LOQ) were 0.175, 0.585 and the proposed method has a good reproducibility 0.85% (RSD %). The enrichment factor was 200 and the percentage of recovery was in the range of 97-100% .The method was successfully applied to the recovery of Cu2+ in different type of water samples. Graphene oxide and its derivates such as GO@SiO2 in this study are full of potential to use as an excellent adsorbent in the extraction method like solid phase extraction (SPE)

Preconcentration of Cr(III) from Natural Water by Modified Nano Polyacrylonitrile Fiber by Methanolamine

Abstract: Modified nano polyacrylonitrile fiber (PANF) was prepared by adding acrylic fibers to methanolamine (MMA) with different concentration solutions. The stability of a chemically modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of modified nano polyacrylonitrile fiber. The application of this modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cr(III) was found to exhibit the highest affinity towards extraction by these modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd) of all the metal ions, showing the highest value reported for Cr(III) to occur by modified nano polyacrylonitrile fiber. The modified nano polyacrylonitrile fiber for selective extraction of Cr(III) were successfully accomplished in aqueous solution as well as preconcentration of low concentration of Cr(III) (60 pg mL -1 ) from natural tap water with a preconcentration factor of 100 for Cr(III) and then off-line Cr(III) in water samples were determined by flame atomic absorption

Financial and Economic Criteria for Evaluating the Performance of Pharmacies

Improving the economic performance of pharmacies need to economic and financial indicators. Despite this necessity, economic and financial performance indicators have not been identified comprehensively in the pharmacy setting. Thus the aim of this study is to determine the economic and financial performance assessment criteria of the pharmacies by specialist’s point of view. This study is a qualitative study in which experts and professional’s point of view were gathered by focus group discussion. 15 health system experts were selected by purposive sampling approach. Data from focus group discussions (FGD) were analyzed by thematic analysis method. Twelve main themes in two scopes were obtained to assess the economic and financial performance of the pharmacy by review of specialists view. These themes are waste rate, profitability, cost control, financial management, economic and political issues, pharmacist, doctor, medical insurance, management system, pharmaceutical companies, cultural issues and public or private administration system of pharmacy.Based on the results of this study, the most important criteria to evaluate the financial and economic performance of pharmacies were identified. These results can be used for to economic and financial performance evaluation of pharmacies

Selenium-capped cyclic peptide nanoparticles for penicillamine drug delivery: A DFT Study

43-50Using a model for performance of penicillamine (PCA) anti-cancer drug on selenium-cyclic peptide nanoparticle (CPSeNP), 11 noncovalent configurations have been investigated. Se8 ring model and cyclooctaglycine have been used for selenium nanoparticle (SeNP) and cyclic peptide (CP), respectively. Binding energies, quantum molecular descriptors and solvation energies have been studied in gas phase and water at M06-2X /6-31G** level of theory. The calculated energies represent the high-energy stability of CPSeNP/PCA 1-11 configurations. Solvation energies showed that drug solubility increases, which is a major factor for their use in drug delivery. Regarding to quantum molecular descriptors such as hardness and electrophilic power, the drug reactivity increases in the vicinity of SeNP. The QTAIM analysis revealed that intramolecular interaction Se-L (L =O, H , S, C , N) plays an important role in the system. Se-L interaction in all configurations is relevant to weak interactions. The configurations that PCA drug is located in parallel with the carrier (CPSeNP) are more stable than penicillamine-CP or penicillamine-SeNP systems

Detection and Prediction of Absence Seizures Based on Nonlinear Analysis of the EEG in Wag/Rij Animal Model

 Background: Epilepsy is a common neurological disorder with a prevalence of 1% of the world population. Absence epilepsy is a form of generalized seizures with Spike wave discharge in EEG. Epileptic patients have frequent absence seizures that cause immediate loss of consciousness.Methods: In this study, it has been tried to explore whether EEG changes can effectively detect epilepsy in animal model applying non-linear features. To predict the occurrence of absence epilepsy, a long-term EEG signal has been recorded from frontal cortex in seven Wag/Rij rats. After preprocessing, the data was transferred to the phase space to extract the brain system dynamic and geometric properties of this space. Finally, the ability of each features to predict and detect absence epilepsy with two criteria of predictive time and the accuracy of detection and its results were compared with previous studies.Results: The results indicate that the brain system dynamic changes during the transition from free-seizure to pre-seizure and then seizure. Proposed approach diagnostic characteristics yielded 97% accuracy of absence epilepsy diagnosis indicating that due to the nonlinear and complex nature of the system and the brain signal, the use of methods consistent with this nature is important in understanding the dynamic transfer between different epileptic seizures.Conclusion: By changing the state of the absence Seizures, the dynamics are changing, and the results of this research can be useful in real-time applications such as predicting epileptic seizures