Modelling the Combined Heat and Power Plants with Steam Turbines in the Study of Energy Security Problems

The paper considers the development of mathematical models of combined heat and power plants that are to be used while modelling the fuel and energy complex. Consideration is given to three methods of combined heat and power plant (CHP) modelling: The first method provides for the simplified modelling based on CHP aggregation in one energy zone; the second method is based on modelling the individual CHP using the accurate parameters of their equipment operation; the third method is based on the use of standard regime diagrams for modelling individual CHP. Analysis of the presented methods of CHP modelling revealed that the third method out of the three methods proposed is most appropriate for mathematical models of fuel and energy complex for studying the fuel and power supply reliability. The experimental part of the paper describes the process of deriving the analytical dependencies of electricity and heat generation versus fuel used by CHP that is obtained by the third method proposed.

Application possibilities of the low-temperature repairs on creep-resistance turbine components from material GX23CrMoV12-1

Papers deals with the problems of repairs at new and also already loaded components of steam and gas turbines. Generally, it is about welding repairs at valve and turbine chambers, transmitters, vane carriers, tripping valve body and so on. There are both technological defects caused by casting (e.g. shrinkage cavities, misruns, porosity and cracks) and defects caused by operation (thermal-stress fatigue, incorrect method of operation, etc.). Many of the mentioned defects take effect not until the final technological method - mostly at machining. However, in this production phase it is not possible to get form the supplier new production elements due to economical and also delivery time reasons. All of that results in delay of production and penalty. As the major aim of this paper, there was to find such repairs techniques which can ensure serviceability of mentioned devices under the standard regime. In these cases is needed to use much lower tempering temperature than under the standard production, mainly because of necessity to eliminate deformation caused by heating of part that is not possible to be subsequently removed by machining.

An evaluation of intracameral mydriasis for routine cataract surgery

BackgroundIntracameral Mydrane might facilitate a more streamlined cataract service and improve the patient experience. There is limited ‘real-world’ evidence of its use in a UK setting.MethodsAs part of a local evaluation of cataract surgery using intracameral Mydrane (group 2; n=60), data were collected on intraoperative pupil size and postoperative visual acuity (VA), as well as the rate of mechanical pupil dilation, intraoperative floppy iris syndrome (IFIS) and complications. Preoperative and theatre turnaround time was recorded and patients completed a validated measure of satisfaction postoperatively. Data were compared with a previous cohort subjected to the existing standard regime of preoperative topical mydriatics (group 1; n=60).ResultsPostoperative VA was comparable between groups (0.09±0.16 vs 0.08±0.15; p=0.59). Pupil size in group 2 was 7.0±1.0 mm prior to capsulorhexis and 6.5±0.29 mm after cortical aspiration, with a smaller pupil in patients on alpha-antagonists (4.7±1.1 mm; p=0.004) at this later time point. Comparing group 2 with group 1, preoperative waiting was less (87 vs 146 min; p<0.0001) and satisfaction was higher (76.0±11.2 vs 66.3±8.6; p<0.0001), although theatre turnaround time was longer (25 min vs 22 min).ConclusionIntracameral mydriasis was clinically effective in most patients undergoing cataract surgery and might be associated with an improved patient experience and a more streamlined preoperative flow. Mydrane represents a licensed alternative to the off-label use of other intracameral mydriatic agents, but was not judged to be a cost-effective intervention for routine use in this particular setting.

New approach to the study of dough mixing processes

The importance of the dough mixing, knowledge of the requirements of individual types of flour in the mixing, and achieving the proper quality with respect to the final dough properties are still actual problems. This study describes the changes in consistency, extensographic energy, and temperature progress in connection with the mechanical energy flow into the dough during mixing on Diosna SP12 kneader. The results of the mixing tests on the first gear indicate that different energy inputs caused different changes in consistency, the development time, and temperature increase of mixed dough. By the alteration of the mixing energy is it probably possible to utilise this energy achieving, dough with a better quality, despite the fact that this was not proved statistically. However, it was proved that energy consumption was more effective in the experimental regimes in comparison to the standard regime. The experimental regimes required a lower energy input, while the achieved consistency level was similar and durability of the positive consistency changes was higher. The temperature increase was significantly higher when the standard regime was used.

La Banque du Canada était-elle nécessaire?

Traditional historiography has inferred that the Canadian government has failed to exercise control over the issue of high powered money during the interwar gold standard period. From this, it was concluded that the Canadian monetary constitution required modifications through the establishment of a central bank. This paper provides new evidence that the Canadian government did exercise monetary control during the period of the interwar gold standard regime and that Canada's record of adherence to the gold standard rules compares favourably with the performance of several other countries.