Evaluation of Sonochemical Destruction of PCE in In Situ Flushing Waste Fluids

Remediation of source zones at sites contaminated with dense non-aqueous-phase liquids using aggressive in situ flushing technologies, such as the addition of chemical additives known as cosolvents, have been implemented and successfully demonstrated in recent field tests. However, treatment of the waste fluids generated from such cleanup technologies has not received much attention. The purpose of this laboratory research was to evaluate the feasibility of using sonication as a method for treating waste fluids produced during in situ alcohol flushing at a site contaminated with a dense non-aqueous-phase liquid. Experimental results showed that sonochemical destruction of perchloroethylene (PCE) followed pseudo first-order kinetics and that increasing ethanol cosolvent percentages in the aqueous effluent resulted in decreasing degradation rates of PCE in solution. The energy efficiency (G = degradation∕energy input) of the sonication treatment also decreased as the ethanol volume fraction increased. Overall, sonication was seen to degrade PCE in aqueous solutions, becoming less effective as the cosolvent fraction increased.     

Phase composition of arc-melted alloys in the ternary systemCe–Al–Cu (Cu-poor portion)

The phase composition of arc-melted alloys in the ternary system Ce–Al–Cu (Cu-poor portion) in the as-cast state were investigated by X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM) techniques. The investigated composition region consists of 16 single-phase, 32 two-phase and 17 three-phase regions. In as-cast state, the solubilities of the solid solution phases were determined. The CeAlCu compound decomposes into three phases: Ce(Al_0.92Cu_0.08)₂, Ce(Al_0.4Cu_0.6)₅ and Ce₂AlCu₂ in as-cast state. Based on the constructed phase composition regions of the investigated alloys in the as-cast state, it reveals that the reported composition region of the bulk glass alloys in the Ce–Al–Cu system falls in the three-phase regions 15–17 with α-Ce₃Al as the common phase which is supposed to play an important role in the glass-forming process.     

Growth and characterisation of triammonium citrate

Single crystals of triammonium citrate are grown from aqueous solution and characterized using X-ray and etching studies. Using single crystal X-ray diffraction, the crystal is found to be orthorhombic with lattice parametersa = 6·223 Å,b = 15·048 Å andc = 11·056 Å. Surface studies on the as-grown faces reveal stratigraphic patterns. Of the several etchants tried, glacial acetic acid appears to be the best etchant for revealing dislocation sites on the as-grown faces.     

Phase rule and independent components

Although the Gibbs phase rule remains one of the cornerstones of thermodynamics, its usefulness has been severely limited by a lack of suitable framework to find the number of independent components in a system. This paper rectifies this shortcoming. It offers a comprehensive method, with suitable examples, to enable the determination of the minimum number of independent composition-parameters, which are to be understood as ‘components’ in the Gibbsian sense. The method offered here is particularly useful for complex systems composed of several elements and many phases. The present work also helps dispel much of the confusion that had beset the concept of independent components since the early days of Gibbs.     

Performance Analysis of Statistical Voice/Data Multiplexing Systems with Voice Storage

In this paper the performances of four statistical voice/data multiplexers are analyzed and compared. The structures of these multiplexers are based on the newly proposed queueing, frame management, and integrated flow control methods. For the queueing purpose, two separate finite voice and data buffers are used to queue voice and data packets independently. For frame management, four versions of master frame management are considered. As for the integrated flow control algorithm, speech coding techniques such as variable rate coding and embedded coding are considered. To evaluate the performances of the multiplexers, analytical formulations are made from the equivalent queueing models of the proposed systems. Then, numerical results on the performance of the multiplexers are obtained by using the Gauss-Seidel iteration method. These results show that there exist tradeoffs between data and voice traffic performances for a given input traffic load and the output channel rate.     

The suitability of muscle of Cirrhinus mrigala in the formation of gel: a comparative electrophoretic study of six tropical carp meats

The annual inland fish production in India is 3.2 million tonnes and above. Aquaculture is around 80% of total inland fish production. The enhanced aquaculture production demands alternate processing methods for better utilisation of the farmed fish. Cirrhinus mrigala is one of the dominated species among cultured Indian major carps, but rated with lowest price. Fish meat with good gel‐forming capacity is a prerequisite in the production of fast‐moving fabricated analogue product. Cirrhinus mrigala had the highest gel strength, i.e. 435 gcm of its fresh meat in comparison with other carps. Apart from the highest protein and salt‐soluble protein nitrogen content in fresh C. mrigala meat, this article also reports that the presence of the darkest thick band of myosin heavy chain and actin in the polyacrylamide gel electrophoresis pattern of salt‐soluble extract of C. mrigala might be another possible reason for the highest gel strength in comparison with other carps. Cirrhinus mrigala contained white meat around 90%. This carp could be suitably used in the preparation of high‐valued fabricated analogue product.     

Analysis of grid connected induction generators driven byhydro/wind turbines under realistic system constraints

Results of an investigation dealing with the behaviour of grid-connected induction generators (GCIGs) driven by typical prime movers such as mini-hydro/wind turbines are presented. Certain practical operational problems of such systems are identified. Analytical techniques are developed to study the behavior of such systems. The system consists of the induction generator (IG) feeding a 11 kV grid through a step-up transformer and a transmission line. Terminal capacitors to compensate for the lagging VAr are included in the study. Computer simulation was carried out to predict the system performance at the given input power from the turbine. Effects of variations in grid voltage, frequency, input power, and terminal capacitance on the machine and system performance are studied. An analysis of self-excitation conditions on disconnection of supply was carried out. The behavior of a 220 kW hydel system and 55/11 kW and 22 kW wind driven system corresponding to actual field conditions is discussed