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Abstract This article reports on changes in climate science, social science, public administration, and policymaking over the past twenty-five years. It responds to Gene I. Rochlin's “retrospective examination” of energy research and the social sciences. In 2014, we find that social scientists are still disadvantaged by policymaker biases and inaccessible deliberative systems, but also better poised to conduct original humanistic energy research and produce targeted social change interventions. We review promising social scientific advancements, particularly in the realm of citizen action research. We conclude with the case study of evidence-based practice, a model from the health field that illustrates how climate change and energy research, practice, and policymaking could benefit from the inclusion of social science perspectives and methods.

Abstract Biome boundaries are expected to be sensitive to changes in climate and disturbance, because it is here that ecological communities are at environmental, ecological or disturbance limits. Using palaeoecology to study ecosystem dynamics at biome boundaries provides opportunities for understanding ecosystem resilience or sensitivity at ecologically meaningful timescales, and under varying climatic and disturbance conditions. The fynbos biome is a megadiverse Mediterranean type shrubland, found only in South Africa, that is threatened by climate change, land-use change and invasion by alien species. We used palaeoecological records from the semi-arid and mesic boundaries of the fynbos biome to test hypotheses regarding ecosystem resilience over timescales of centuries to millennia. We hypothesised that fynbos would expand at its mesic boundary at the expense of afrotemperate forest under drier and / or more fire prone conditions. In contrast, we hypothesised that at the semi-arid boundary, fynbos would expand at the expense of succulent karoo under wetter and cooler and / or more fire-prone conditions. Contrary to our expectations, the fossil pollen record at both biome boundaries showed remarkable stability at centennial - millennial timescales. To explain our results, we generated new hypotheses exploring possible mechanisms that might confer resilience. At the mesic (temperate) boundary, we suggest that decreased seasonality of rainfall during drier phases favoured fire and fynbos persistence, while in wetter periods, increased seasonality of rainfall resulted in enhanced summer drought stress, inhibiting forest expansion. At this boundary, internal reorganisation from grassy to proteoid fynbos states conferred resilience through resistance. At the succulent karoo boundary, we suggest that increased aridity was offset by less seasonality of rainfall, which enhanced biomass and allowed fire to persist, favouring persistence of fynbos. At this boundary, fynbos sensu stricto retreated during arid phases but recovered during climate amelioration, consistent with resilience through recovery. In both cases, this mega-diverse, disturbance-adapted flora provided a range of traits that enabled fynbos to persist despite environmental perturbation. Our findings agree with general observations that for ecosystems in regions of ample resource availability (i.e. at the mesic boundary), biotic interactions and disturbance tend to become more important in ecosystem dynamics, whereas in regions of scarce resources (in this case water scarcity at the semi-arid boundary) abiotic stress is more important. Our findings contribute to debates over the mechanisms that confer resistance and resilience to environmental change. Understanding and conserving the processes and mechanisms underpinning its resilience will be critical to effective conservation planning.

Abstract Si-wafers for solar cells were cast in a size of 50 × 46 × 0.5 mm 3 by a direct casting method. A graphite mold coated by boron nitride (BN) powder was used in order to prevent the reaction between carbon and the molten silicon. Without any coating, the reaction of the Si melt to the graphite mold was very severe. In the case of BN coating, SiC was formed in the shape of tiny islands on the surface of the Si wafer by the reaction between the Si-melt and the carbon of the graphite mold at high temperature. The grain size was about 1 mm. The efficiency of the Si solar cell was about 0.5% under AM1.5 conditions. It was lower than that of a Si solar cell fabricated with a common single- (sc, 3.0%) and poly-crystalline (pc, 1.0%) Si wafer, which showed much lower efficiency than that of other commercial pc- or sc-Si solar cell (10–15%).

We present a method for efficient calculation of intramolecular vibrational excitations of H2O inside C60, together with the low-energy intermolecular translation-rotation states within each intramolecular vibrational manifold. Apart from assuming rigid C60, this nine-dimensional (9D) quantum treatment is fully coupled. Following the recently introduced approach [P. M. Felker and Z. Bacic, J. Chem. Phys. 151, 024305 (2019)], the full 9D vibrational Hamiltonian of H2O@C60 is partitioned into two reduced-dimension Hamiltonians, a 6D one for the intermolecular vibrations and another in 3D for the intramolecular degrees of freedom, and a 9D remainder term. The two reduced-dimension Hamiltonians are diagonalized, and their eigenvectors are used to build up a product contracted basis in which the full vibrational Hamiltonian is diagonalized. The efficiency of this methodology derives from the insight of our earlier study referenced above that converged high-energy intramolecular vibrational excitations of weakly bound molecular complexes can be obtained from fully coupled quantum calculations where the full-dimensional product contracted basis includes only a small number of intermolecular vibrational eigenstates spanning the range of energies much below those of the intramolecular vibrational states of interest. In this study, the eigenstates included in the 6D intermolecular contacted basis extend to only 410 cm−1 above the ground state, which is much less than the H2O stretch and bend fundamentals, at ≈3700 and ≈1600 cm−1, respectively. The 9D calculations predict that the fundamentals of all three intramolecular modes, as well as the bend overtone, of the caged H2O are blueshifted relative to those of the gas-phase H2O, the two stretch modes much more so than the bend. Excitation of the bend mode affects the energies of the low-lying H2O rotational states significantly more than exciting either of the stretching modes. The center-of-mass translational fundamental is virtually unaffected by the excitation of any of the intramolecular vibrational modes. Further progress hinges on the experimental measurement of the vibrational frequency shifts in H2O@C60 and ab initio calculation of a high-quality 9D potential energy surface for this endohedral complex, neither of which is presently available.

Data from the Global Precipitation Climatology Centre (GPCC) were used in investigating long-term variability of anomalies of the total amount of atmospheric precipitation within the Selenga river basin in July. We identified several long periods (four years and longer) with negative precipitation anomalies: 1935–1939, 1955–1958, 1977–1981, 2007–2011, and 2013–2017. The last period is characterized by the smallest precipitation amount. Day-to-day variations in total precipitation were also analyzed for each July from 1982 to 2016. The analysis revealed a tendency to a decrease of the number of days with a large precipitation amount and to an increase of dry periods. Based on ECMWF Era Interim data, we examined the features in the atmospheric blocking Europe, Siberia and the Far East for periods with large and small precipitation amounts within the Selenga river basin. To identify the blocking in the atmosphere used the southern gradient of the geopotential. It was shown that in periods with large precipitation amounts blockings occurred most frequently over Eastern Siberia and more rarely over Europe and the Far East (especially if they were accompanied by blocking over Western Siberia). Atmospheric precipitation within the Selenga basin is associated not only with blocking but also with the position of the jet stream and with dynamic blocking formation schemes. The significance of these factors has been demonstrated in a number of specific situations of the atmospheric circulation in years with large and small precipitation amounts within the Selenga basin. Long-term transformations of these characteristics caused by climate change and the general atmospheric circulation can lead to a disturbance of the correlations between blocking and precipitation amounts within the river basin. In all likelihood, the correlation of blocking with precipitation regimes, rather than with precipitation in the region, will be more rigid. A functional dependence of the Selenga flow on climate change appears to be determined by the position of the monsoon front and by the wave properties of atmospheric flows in midlatitudes.

The objective of this study is to estimate the non-linear effect of energy consumption i.e. oil, gas, electricity, and coal consumption on CO2 emission in South Asian countries. The study uses annual panel data of three South Asian countries i.e. Bangladesh, India, and Pakistan from 1985 to 2017 and applies panel non-linear ARDL methodology to examine the long-run and short-run relationship. Results show that an increase in gas, electricity, coal, and electricity consumption leads to an increase in the carbon dioxide emission, whereas decrease in electricity and coal consumption reduces the carbon dioxide emissions in the long run. Non-linear relationship exists between electricity consumption and CO2 emissions as well as between coal consumption and CO2 emissions in South Asian countries in the long run. Results of short run dynamics of individual countries show that non-linear relationship exists between oil consumption and CO2 emissions, electricity consumption and CO2 emissions, and coal consumption and CO2 emissions in Bangladesh and Pakistan. Research and development centers are required to control pollution through new technologies, while discourage to use higher electricity and coal consumption as a source of energy for a healthier environment.

The modeling of energy consumption in buildings must consider occupancy as a relevant input, since it plays a very important role in the overall building's energy consumption. Frequently, buildings lack of permanent occupancy monitoring solutions. However, they may include data sources that are correlated with real building occupancy. This study proposes a new methodology for energy consumption modeling, supported by these alternative data sources, such as the number of vehicles in a parking lot. The aim is to mitigate investment in permanent occupancy monitoring solutions. The proposed methodology makes use of short-term real occupancy monitoring for model fitting, to enable the development of occupancy and energy consumption models, based on these alternative data sources.

In this paper, the model of low temperature fractionation CO2 capturing process is established with HYSYS to carry out the simulation of the process. According to the simulation results, it is concluded that as the CO2 content in the feed gas raises, the CO2 product purity increases and the cooling energy cost of the system decreases. As the CO2 product purity rises, the cooling energy cost increases more and more rapidly. According to the 91.0% CO2 content feed gas, the optimized fractionation pressure is 3.1MPa and the corresponding liquefaction temperature and condensing temperature is-20°C and-24°C respectively.

Abstract This paper reports on the effects of the influence of the MILD combustion mode relative to conventional combustion on the overall performance of a hybrid solar receiver combustor (HSRC) operating under the combustion-only mode of operation. The influence of the dominant reactor geometrical parameters and level of dilution of the combustion air stream on the thermal efficiency, heat transfer mechanisms and heat flux distribution within the cavity were investigated using a three-dimensional computational fluid dynamics (CFD) model of the device. It was found that the use of MILD combustion leads to an increase of the thermal performance of the device in comparison with a conventional flame, owing to a larger rate of convective heat transfer. Also, the level of dilution of the combustion air influences significantly the rate of radiative heat transfer and the ratio of radiative to convective heat transfer rate. The thermal efficiency of the device was also found to increase with the length-to-diameter cavity ratio ( L / D ) and/or a reduction of the jet inclination angle. In addition, operation in the MILD regime can achieve a similar thermal performance to the solar mode of operation given suitable configurations, such as the use of either a cavity of sufficiently length ( L / D > 5) or an appropriate arrangement of the HTF pipes within the cavity. However, the calculated heat flux distributions on the receiver pipes were found to be significantly different under the two modes of operation, implying that the difference in heat flux distribution is a key parameter that needs to be considered in the design strategies and materials selection. The present investigation also identified the configurations for which the analytical model of the device (operating in the MILD regime), developed previously, yields reasonable accuracy for the thermal efficiency of the device, notably for the case of long cavities ( L / D > 5).

PurposeThe question being assessed is whether changes in the degree of global geopolitical risk (GPR), as defined by the framework developed by Iacoviello (2018), can be used to improve allocative efficiency, thereby increasing investment returns on oil commodities.Design/methodology/approachUsing the linear and nonlinear model, this paper analyzes the impact of GPR on returns of oil prices (BRENT, WTI and Organization of Petroleum Exporting Countries), as well as the short- and long-run relationship between GPR and oil prices.FindingsThe results of the impulse response function indicates that oil prices do not respond to shocks in GPR. The results of the Granger causality test show that oil returns are not caused by GPR. The regression analysis and autoregressive distributed lag results show that there is no significant impact of GPR on the returns of oil.Originality/valueThis is unique among the literature in that it identifies and isolates the relationship between GPR and oil market pricing. Insight into the lag in market response and the degree to which GPR can be used to estimate oil prices using curvilinear models are derived from the analysis.