Superspace and classical field theory

Imperial Users onl

Effective Consumption Scheduling for Demand-Side Management in the Smart Grid using Non-Uniform Participation Rate

Periods of peak consumer demand in today’s electricity sector are expensive to satisfy and can be the source of power failures. One possible solution is the use of demand-side management (DSM) applying dynamic pricing mechanisms. However, instead of reducing peak loads, these mechanisms can lead to peak-shifting due to the herding effect of consumers’ load-shifting behavior. To overcome this problem, we explore strategies of assigning (non-uniform) participation rates to consumers. We use a generic method to find a near-optimal distribution setting for participation rates. Our method allows DSM designers to tune the system toward consumer convenience. This means less frequent consumption schedule changes, in the price of system performance. In addition, consumers do not need to reveal their detailed consumption schedules (hence, their privacy is preserved). Using experiments, we show the impact of the herding effect and evaluate the effectiveness of the proposed solution. We thereby demonstrate price fairness for consumers. Finally, we apply our solution to a more realistic environment – one where consumers change their consumption behavior every day

Tuning of catalytic activity by thermoelectric materials for carbon dioxide hydrogenation

An innovative use of a thermoelectric material (BiCuSeO) as a support and promoter of catalysis for CO2 hydrogenation is reported here. It is proposed that the capability of thermoelectric materials to shift the Fermi level and work function of a catalyst lead to an exponential increase of catalytic activity for catalyst particles deposited on its surface. Experimental results show that the CO2 conversion and CO selectivity are increased significantly by a thermoelectric Seebeck voltage. This suggests that the thermoelectric effect can not only increase the reaction rate but also change chemical equilibrium, which leads to the change of thermodynamic equilibrium for the conversion of CO2 in its hydrogenation reactions. It is also shown that this thermoelectric promotion of catalysis enables BiCuSeO oxide itself to have a high catalytic activity for CO2 hydrogenation. The generic nature of the mechanism suggests the possibility that many catalytic chemical reactions can be tuned in situ to achieve much higher reaction rates, or at lower temperatures, or have better desired selectivity through changing the backside temperature of the thermoelectric support

The effect of the combination of Mediterranean diet and leisure time physical activity on the risk of developing acute coronary syndromes, in hypertensive subjects

The World Health Organization reports that the number of hypertensives, worldwide, is estimated to be 600 million people. In addition a considerable proportion of hypertensive subjects remains untreated or uncontrolled. In this work we investigated the combined effect of physical activity and Mediterranean diet on coronary risk, in hypertensives. Thus we randomly selected, from all Greek regions, 848 hospitalised patients (695 males, 58 +/- 10 years old and 153 females, 65 +/- 9 years old) with a first event of coronary heart disease (CHD) and 1078 paired, by sex, age, region controls, without any suspicions for CHD. Physically active were those who reported non-occupational physical activity more than once per week. Subjects ‘closer’ to the Mediterranean diet were assessed through a special nutrient questionnaire. A total of 418 (49%) of the patients and 303 (28%) of the controls were hypertensive. Of these, 115 (27%) patients and 70 (23%) controls were untreated, 148 (35%)-111 (36%) were uncontrolled and 155 (38%)-122 (41%) were controlled (P-value <0.01). One hundred and sixty-two (19%) of the patients and 265 (25%) of the controls (P < 0.01) were ‘closer’ to the combination of Mediterranean type of diet and physical activity. The analysis showed that the previous combination is related to a 25% reduction of the coronary risk in controlled hypertensive subjects (OR = 0.75, P < 0.01), a 11% reduction in untreated (OR = 0.89, P < 0.05) and 17% reduction (OR = 0.83, P < 0.05) in uncontrolled, after adjusting for age, sex, educational and financial level and the conventional cardiovascular risk factors. Consequently, the adoption of Mediterranean diet by physically active subjects seems to reduce significantly the coronary risk and prevent, approximately, the one-third of acute CHD, in controlled hypertensive subjects