Assessment of underground cable ratings based on distributed temperature sensing

Numerous power utilities have installed advanced distributed temperature sensing (DTS) systems to measure the temperature of underground cables. This paper presents a general procedure for real-time assessment of underground cable ratings based on DTS. After the identification and location of hot spots on a cable, the cable installation data, load, and DTS-recorded temperature over a period of time are used to estimate soil thermal parameters and assess cable ratings under normal and overloading conditions. In order to accurately estimate soil thermal parameters, a combined technique of the finite-element method and gradient-based optimization is used. The technique was validated in the laboratory and applied to a rating assessment of a 230-kV/500-MVA cable circuit. The assessed continuous and emergency ratings are helpful in improving the operation of this circuit.     

Allocation of fixed costs in distribution networks with distributed generation

In this paper, we propose a method for the allocation of fixed (capital and nonvariable operation and maintenance) costs at the medium voltage (MV) distribution level. The method is derived from the philosophy behind the widely used MW-mile methodology for transmission networks that bases fixed cost allocations on the "extent of use" that is derived from load flows. We calculate the "extent of use" by multiplying the total consumption or generation at a busbar by the marginal current variations, or power to current distribution factors (PIDFs) that an increment of active and reactive power consumed, or generated in the case of distributed generation, at each busbar, produces in each circuit. These PIDFs are analogous to power transfer distribution factors (PTDFs). Unlike traditional tariff designs that average fixed costs on a per kWh basis across all customers, the proposed method provides more cost-reflective price signals and helps eliminate possible cross-subsidies that deter profitable (in the case of competition) or cost-effective (in the case of a fully regulated industry) deployment of DG by directly accounting for use and location in the allocation of fixed costs. An application of this method for a rural radial distribution network is presented.     

Software architecture-centric methods and agile development

The agile software development paradigm and plan-driven approaches each have their strengths and shortcomings. The former emphasizes rapid, flexible development, while the latter emphasizes project and process infrastructure. Many practitioners, particularly of agile methods, tend-to view software architecture in light of the plan-driven side of the spectrum. They think that architecture-centric methods are too much work, equating them with high-ceremony processes emphasizing document production. But many elements make up a successful development approach, including process, product, technology, people, and tools. Software architecture is part of product quality and isn't tied to a particular process, technology, culture, or tool. This article explores the relationship and synergies between architecture-centric design and analysis methods and the extreme programming framework. We chose to focus on XP because it's one of the most mature and best-known agile practices.     

Dissipative processes during cyclic hardening of spheroidal graphite cast iron

The hardening of spheroidal graphite cast irons alloyed by vanadium via chemical dispersion has been studied. Strain hardening is experimentally found to effectively occur in a cast iron with a relatively low vanadium content (0.5 wt %). Dissipative processes in cast irons with dispersed vanadium carbide inclusions are analyzed. An increase in the degree of dispersion of vanadium carbide inclusions is shown to favor more complete dissipation of the supplied energy into heat and decreases the level of damage in the material.     

Energy pricing policies in developing countries

Government energy pricing policies have multiple and often conflicting objectives: economic efficiency, government revenues (for both parastatal supply companies and the treasury), maintenance or improvement of income distribution, promotion of particular sectors (such as industrial exporters and local resource development) demand management and security of supply. It is important to examine the impacts on and the trade-offs between these objectives resulting from alternative policies in order to assist in policy selection. This article discusses the more important objectives and their conflicts and outlines an approach for the quantitative examination of alternative policies.     

On the structure of the flow due to the collision of opposed,vertical, free convection,boundary layers

Preliminary experimental results are reported for the structure of the flow due to the collision of a pair of boundary layers driven towards each other by buoyant forces along a vertical wall. Of the possible parameters characterizing the flow, a Rayleigh number ratio, R, and a dimensionless temperature difference, n, emerge as important. When 0.6 < R 2.0: if n < 0.20, the approaching streams merge in a two-dimensional streamlined manner; if n > 0.20 “fingering” of fluid between the streams and cross-stream secondary flows occur.     

Stoichiometric dye-binding procedure for the determination of the reactive lysine content of soya bean protein

A new analytical method has been developed for the determination of the reactive lysine content of soya bean protein. The method is based on the reaction of the free basic groups of the protein with 1-phenylazo-2 naphthol-6,8 disulphonic acid. With regard to the stoichiometry of the procedure, it has been proved, contrary to earlier reports, that the basic amino acids, histidine, arginine and lysine, each combine with one mole of the dye. After acylation with propionic anhydride lysine alone loses its dye reactivity. The usefulness of the proposed method has been demonstrated by the determination of the reactive lysine content of several untreated, heat-treated and acid-treated soya bean samples. The results show that heat damage of about 5% in reactive lysine content can be measured in 1·5 h with good reproducibility.     

Use of lactose in the pharmaceutical and chemical industry

Lactose is used in the pharmaceutical industry for tabletting. For this purpose it must be purified to pharmaceutical grade. Many of the properties of crystallized lactose make it suitable for tabletting, but further research is needed into the mechanisms involved in the prom. Lactose can also be used as a basis for the production of lactulose lactitol and lactobionic acid. These processes are described, and possible commercial applications for the products are discussed.