La cultura médica instrumental: los viajes políticos de los esfigmógrafos entre Europa y América
Generally explained by the association between precision and instrument, the instrumental dominion of medicine in actual days is assumed as a natural and necessary destiny. Placed in the practices of Mexican physicians of the XIX century, I discuss this naturalized image of medical instruments. Taking as a case the Sphygmograph, device recorder of the cardiac pulse, I interrogate the reasons of the massive import of instruments from the European markets. I have found that the political search for affirming normality and civilization of the Mexican population encircle an epistemological dimension; the instruments are revealed as appliances of knowledge and objects of consumption, in this case, of the colonial market, which hierarchies determined how in this side of America medical doctors were creating knowledge and instruments importing Europe’s instruments.
Daniel Vergara Lope and Carlos Monge Medrano: two pioneers of high altitude medicine.
Daniel Vergara Lope from Mexico and Carlos Monge Medrano from Peru were brilliant scientists in their own countries. Both scientists studied high altitude physiology and defined the physiological and anatomical mechanisms of adaptation to high elevations. The Mexican physiologist proposed his ideas 40 years before his Peruvian counterpart. This paper studies the contribution of Vergara Lope and Monge Medrano to the understanding of high altitude medicine and proposes explanations of why history has given priority to Monge, whereas Vergara Lope is relegated to anonymity.
Energy and exergy analysis of a new cogeneration system based on an organic Rankine cycle and absorption heat pump in the coal-fired power plant
Abstract A new cogeneration system based on ORC (organic Rankine cycle) and AHP (absorption heat pump) is presented to achieve the dual effects of improving power output and heating capacity in a coal-fired power plant. The heat source for heating is firstly led into the ORC to generate power, and then is led into the AHP as the driving heat source to recycle waste heat from exhausted steam of the ST (steam turbine) when the energy grade is reduced to a level that matches with the heating energy grade. On the basis of the thermodynamic first and second law, focusing on 135 MW coal-fired power plant, the energy and exergy analyses of traditional cogeneration system and new cogeneration system with ORC and AHP have been completed. Compared to the traditional cogeneration system, the power output and heating capacity are respectively increased by 1.47 MW and 32,106.64 kW when the flow rate of heating extraction steam is 40 kg/s. The integral thermal and exergy efficiencies are improved by 9.38% and 1.71%. Moreover, the coal consumption decrement for power generation and heat-supplying both augments with increasing heating extraction flow rate and decreasing load. The new presented scheme can not only reduce the irreversible loss of the cogeneration system but also save coal consumption.