Hydropower at Canford: A Case Study in Investment Appraisal

This paper reports a case-study investigation into the economic desirability of generating hydroelectric power from the River Stour for Canford School, Dorset, as part of a larger feasibility study, which won a 1985 Molins Design Prize. A parametric discounting approach to net present-value assessment was used to examine the economic benefits of installing a small run-of-river hydropower scheme. Sensitivity analysis was used to clarify the effects of uncertainties in the limited cost and rate data available at the feasibility stage of the project. The role of the economic analysis in relation to other aspects of the feasibility study is indicated.     

Accuracy of the IOS approximation for highly inelastic R-T collisional energy transfer

Rate constants for rotational excitation of CO by collisions with He atoms computed within the infinite order sudden (IOS) approximation are compared with accurate quantum (coupled-states) and classical trajectory values. Taking the IOS energy as the initial kinetic energy for upward. 0 → J, transitions is found to overestimate the rates, especially for higher J (larger inelasticity). Taking the IOS energy as the initial energy for downward, J → 0, transitions underestimates the rates by a comparable amount. The geometric average of IOS rates computed in these two ways is found to provide accurate values.     

The reaction of atomic oxygen and hydrogen with nitric acid

The reactions have been studied in a discharge-flow system. Kinetic studies were made using resonance fluorescence for the measurement of atom concentrations. Based on the rates of atom loss, the following upper limits were obtained for the rate constants: Observed reaction in the H? HNO₃ system is at least partially due to an autocatalytic chain removal of both reactants. Diagnostic tests have suggested that OH, NO₂, and NO₃ are the chain carriers.     

Radii of single-proton states in isotopes of tin

Sub-Coulomb (t, α) reactions have been employed in the determination of the rms radii of the $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$, $\text{2}\text{p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and $\text{2}\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ proton orbits in ^{112,116,118,120,124}Sn. The experimental values are compared to the results of Hartree-Fock calculations.     

Reversible ferromagnetic-antiferromagnetic transformation upon dehydration-hydration of the nanoporous coordination framework, [Co3(OH)2(C4O4)2].3H2O

Reversible crystal-to-crystal transformation accompanied by change from ferromagnetic to antiferromagnetic ground states at 8 K upon dehydration-rehydration of the nanoporous coordination framework [CoII3(OH)2(C4O4)2].3H2O.     

Determination of work functions near melting points of refractory metals by using a direct-current arc

A direct-current arc in argon at atmospheric pressure was used to determine effective work functions of refractory metals, including tantalum, tungsten, molybdenum, and niobium. The procedure is experimentally advantageous because surface cleanliness of the specimen is not critical, high vacuum is not required, and the anode-cathode spacing is not critical. The experimental procedure involves striking an arc to a metal wire cathode to form a melted ball having an emitting area defined by its diameter. The literature melting point of the metal is taken as the emitting temperature. By using these parameters and the known arc current, effective work functions were calculated from the Richardson-Dushman equation. The calculated work functions agree with recommended handbook values to within about 0.1 V and have typical repeatabilities of 0.02 V. By varying the arc current, Richardson plots can be made over a temperature range from a few hundred degrees below the melting point to about 50° over the melting point of the test metal. A Richardson plot over this temperature range is presented for tantalum.     

The Optimal Allocation of Resources to a Variable Timetable

In this note we describe a programming method for allocating resources to a variable timetable. It is illustrated in terms of a restricted version of a general programming model for resource allocation to a CPA network, but it can be used for more general versions of the CPA model, and for the scheduling of ships, aeroplanes, buses and so on. It makes use of the standard trans-shipment transportation problem framework, although in practice the assignment matrix need not be constructed. A highly efficient initial solution is obtained first, then optimized via a primal method of dealing with the "either-or" constraints which arise because of the variability in the timetable.     

Progressive Basic Decision CPM

PERT and CPM are two valuable tools for the planning, scheduling and controllingof projects, but they do not on their own deal with the interdependence between planning resource utilization or direct cost expenditure and sclheduling with its overhead cost (penalty cost and/or reward bonus) implications. Several approaches to overcome this deficiency are possible, this paper dealing with one known as Decision CPM. The most recent approach to the Decision CPM problem known to the authors leads to relatively large integer programming problems which are solved as such. This paper considers a restricted formulation of the Decision CPM problem in an integer programming framework, and shows how it may be solved relatively easily witlhout resort to integer programming methods. Extensions of the restricted model are also considered briefly, some of which pose no difficulties, while others suggest the need for a hybrid of other approaches and that described here.