Egg development, hatching rhythm and moult patterns in Paralomos spinosissima (Decapoda: Anomura: Paguroidea: Lithodidae) from South Georgia waters (Southern Ocean)

Larval release, hatching rhythms and moult patterns were examined in a captive population of the subantarctic lithodid, Paralomis spinosissima from the South Georgia and Shag Rocks region. Larvae hatched throughout the year with the majority of females starting to release larvae at the end of the austral summer and beginning of autumn. Larval release continued over a period of up to 9 weeks with high variability in the numbers that hatched each day. A similar seasonal pattern to hatching was evident in the moulting of females. Intermoult period for two adult females (CL = 63 and 85 mm) ranged from 894 to 1,120 days while an intermoult period for males was estimated to be in excess of 832 days. The results are consistent with other species of Paralomis and are discussed in relation to physiological and environmental adaptations to the cold-water conditions south of the Antarctic Convergence

RANKINE: a Computer Software Package for the Analysis and Design of Steam Power Generating Units

Introduction Nearly all major electric-generating power systems run through a series of processes which is based upon the theoretical thermodynamic cycle called the Rankine cycle. Because the Rankine cycle is the basis for steam power cycles, its analysis is vital to the design of power systems and to ensuring their proper operation. By introducing additional components, such as feedwater heaters or reheat legs, or adjusting the operating temperatures and pressures, a Rankine cycle analysis can be used to maximize the thermal efficiency and exergetic efficiency (second law effectiveness) within the constraints of turbine exit quality and pump capacity. The process of analyzing these Rankine cycles and attempts at optimizing the operating conditions can be very complex as well as time consuming. Such an analysis dictates the use of the computer. A software package (RANKINE) has been designed and tested which will solve a wide range of Rankine cycle problems very quickly. This software package is the subject of this paper. Another use of the software package is in the instruction of undergraduate mechanical engineering students. Because the Rankine cycle is the basis for steam power cycles, it is a primary topic covered in an intermediate thermodynamics course. In order to provide the students with a feeling for how the ideal Rankine cycle may be modified in order to model any actual steam power cycle, a large number of examples need to be worked. With the RANKINE software package, the students will be able to gain a feeling for actual steam power cycles in a reasonable time period. Previous software packages dealing with Rankine or modified Rankine cycles fall into one of three groups. There have been some very simple programs developed which can b