Separation of 133Ba and 137Cs from Mixtures of 133Ba and 137Cs by Environmentally Benign PEG-Based Aqueous Biphasic System

Journal of Solution Chemistry - Thermodynamics of the protonation of chelidamic acid (4-oxo-1,4-dihydropyridine-2,6-dicarboxylic acid) was studied using potentiometry and calorimetry in...     

Microfunnel‐filter‐based emulsification microextraction followed by gas chromatography for simple determination of organophosphorus pesticides in environmental water samples

A simple and fast method named microfunnel‐filter‐based emulsification microextraction is introduced for an efficient determination of some organophosphorus pesticides including diazinon, malathion, and chlorpyrifos in the environmental samples including the river, sea, and well water. This method is based upon the dispersion of a low‐toxicity organic solvent (dihexyl ether), as the extractant, in a high volume of an aqueous sample solution (45 mL). It is implemented without a centrifugation step, and using a syringe filter and a micro‐funnel, the phase separation and transfer of the enriched analytes to the gas chromatograph are simply achieved. By filtration of the extractant phase, a suitable sample clean‐up is obtained, and the total extraction time is just a few minutes. The factors influencing the extraction efficiency are optimized, and under the optimal conditions, the proposed method provides a good linearity (in the range of 15–1500 ng/mL (R² > 0.996). A high enrichment factor is obtained (in the range of 306–342), and the method provides low limits of detection and quantification (in the ranges of 4–8 and 15–25 ng/mL, respectively).     

On the relationship between distinction and irreducibility of parabolic induction

Let $U_{2n}$ denote the quasi-split unitary group over 2n variables with respect to a quadratic extension $E/F$ of p-adic fields. In this short note, we relate ${\mathrm{GL}}_n(F)$-distinction of ladder representations of ${\mathrm{GL}}_n(E)$ with irreducibility of its Siegel parabolic induction in $U_{2n}$.     

Formulation and characterization of a biocompatible microemulsion composed of mixed surfactants: lecithin and Triton X-100

We report on the formation and characterization of a biocompatible microemulsion (ME) system composed of lecithin (L), Triton X-100 (T) as the surfactant(s), butyl lactate (BL) as the cosurfactant, and isopropyl myristate (IPM) as the oil phase and water. Detailed phase construction reveals that mixing of surfactants (L and T) produces larger single-phase ME region compared to L. In the mixed surfactant systems, a three-phase body appears which is otherwise not obtained in the single surfactant counterparts signifying the synergistic solubilization behaviour upon mixing. The maximum solubilization capacity decreases as the content of T increases in the mixture. Viscosity, conductance and adiabatic compressibility measurements of the single-phase ME systems at a constant amphiphile concentration (80 % w/w) show a linear trend with increasing water content revealing a droplet-type structure of all the studied formulations. FTIR studies in the water-in-oil (w/o) region identify the presence of three distinct types of water molecules in these systems and their relative content changes with the interfacial composition as well as the total water content in the system. Our study offers a biocompatible mixed ME system in which the physical properties do not differ much from those of the lecithin-based systems with the additional advantage of having higher solubilization capacity, low pH dependency and low viscosity, which renders its potential to be used for specific pharmaceutical applications.     

A literature review on dynamic pricing of electricity

Revenue management and dynamic pricing are concepts that have immense possibilities for application in the energy sector. Both can be considered as demand-side management tools that can facilitate the offering of different prices at different demand levels. This paper studies literature on various topics related to the dynamic pricing of electricity and lists future research avenues in pricing policies, consumers’ willingness to pay and market segmentation in this field. Demand and price forecasting play an important role in determining prices and scheduling load in dynamic pricing environments. This allows different forms of dynamic pricing policies to different markets and customers depending on customers’ willingness to pay. Consumers’ willingness to pay for electricity services is also necessary in setting price limits depending on the demand and demand response curve. Market segmentation can enhance the effects of such pricing schemes. Appropriate scheduling of electrical load enhances the consumer response to dynamic tariffs.     

Applicability and effectiveness of classifications models for achieving the twin objectives of growth and outreach of microfinance institutions

Measuring performance of microfinance institutions (MFIs) is challenging as MFIs must achieve the twin objectives of outreach and sustainability. We propose a new measure to capture the performance of MFIs by placing their twin achievements in a 2 × 2 grid of a classification matrix. To make a dichotomous classification, MFIs that meet both their twin objectives are classified as ‘1’ and MFIs who could not meet their dual objectives simultaneously are designated as ‘0’. Six classifiers are applied to analyze the operating and financial characteristics of MFIs that can offer a predictive modeling solution in achieving their objectives and the results of the classifiers are comprehended using technique for order preference by similarity to ideal solution to identify an appropriate classifier based on ranking of measures of performance. Out of six classifiers applied in the study, kernel lab-support vector machines achieved highest accuracy and lowest classification error rate that discriminates the best achievement of the MFIs’ twin objective. MFIs can use both these steps to identify whether they are on the right path to attaining their multiple objectives from their operating characteristics.     

Natural convective heat transfer in water enclosed between pairs of differentially heated vertical plates

This paper presents the results of an experimental study of buoyancy-driven convective heat transfer between three parallel vertical plates, symmetrically spaced with water as the intervening medium. The centre plate was electrically heated, while the other side plates were water-cooled forming two successive parallel vertical channels of dimensions 20 cm × 3.5 cm × 35 cm (length W, gap L, height H) each. Top, bottom and sides of the channels were open to water in the chamber which is the novel aspect of this study. Plate surface temperature and bath temperature at different levels of height from the bottom of channel were measured by K-type thermocouples. Experimental data have been correlated as under:

Operational risk: Emerging markets,sectors and measurement

The role of decision support systems in mitigating operational risks in firms is well established. However, there is a lack of investment in decision support systems in emerging markets, even though inadequate operational risk management is a key cause of discouraging external investment. This has also been exacerbated by insufficient understanding of operational risk in emerging markets, which can be attributed to past operational risk measurement techniques, limited studies on emerging markets and inadequate data.