Generating a dynamical M2 brane from super-gravitons in a pp-wave background

We present a detail study of dynamically generating a M2 brane from super-gravitons (or D0 branes) in a pp-wave background possessing maximal spacetime SUSY. We have three kinds of dynamical solutions depending on the excess energy which appears as an order parameter signalling a critical phenomenon about the solutions. As the excess energy is below a critical value, we have two branches of the solution, one can have its size zero while the other cannot for each given excess energy. However there can be an instanton tunnelling between the two. Once the excess energy is above the critical value, we have a single solution whose dynamical behavior is basically independent of the background chosen and whose size can be zero at some instant. A by product of this study is that the size of particles or extended objects can grow once there is a non-zero excess energy even without the presence of a background flux, therefore lending support to the spacetime uncertainty principle.

The mechanics of landslide mobility with erosion

Erosion can significantly increase the destructive power of a landslide by amplifying its volume, mobility and impact force. The threat posed by an erosive landslide is linked to its mobility. No mechanical condition has yet been presented for when, how and how much energy erosive landslides gain or lose. Here, we pioneer a mechanical model for the energy budget of erosive landslides that controls enhanced or reduced mobility. Inertia is related to an entrainment velocity, is a fundamentally new understanding. This ascertains the true inertia of erosive landslides, making a breakthrough in correctly determining the landslide mobility. Erosion velocity, which regulates the energy budget, determines the enhanced or reduced mobility. Newly developed energy generator offers the first-ever mechanical quantification of erosional energy and a precise description of mobility. This addresses the long-standing question of why many erosive landslides generate higher mobility, while others reduce mobility. We demonstrate that erosion and entrainment are different processes. Landslides gain energy and enhance mobility if the erosion velocity exceeds the entrainment velocity. Energy velocity delineates distinct excess energy regimes. Newly introduced mobility scaling and erosion number deliver the explicit measure of mobility. Presented dynamical equations correctly include erosion induced net momentum production.

Feasible location identification & potential assessment of micro-hydropower: Gilgel Beles River, Upper Blue Nile Basin, Ethiopia

Ethiopia is endowed with huge natural resources especially water resources that is why Ethiopia is the water tower of East Africa. But having the capability of generating a huge amount of electricity Ethiopia is under an energy crisis especially the rural peoples of Ethiopia. To overcome this problem utilization of renewable sources of energy like wind, solar and hydro are the best options. Hence, the objective of this study is to assess and identify the micro hydropower potential of the Gilgel-Beles river which is located in the Amhara and Benishangul Gumuz regions of Ethiopia. For data preparation and analysis, Arc GIS, HEC-GEOHMS, and HOMER software were used. Typical energy demand categories (lighting, radio, television, injera Mitad, stove, water pumps, schools, churches, and health centers) for Alefa Kacha Village were considered. The result showed that there is 88% excess energy from Hp site8 to supply other villages in addition to Alefa Kacha. Based on the estimated total technical ROR hydro potential of Gilgel-Beles River 660.01Kw technical power and 5608.222MWh annual energy was determined. The amount of coal or wood that can be saved per year as a result of the energy produced by the potential Micro Hydropower of Gilgel-Beles River is also determined. Finally, 9 sites were identified and a ranking of hydropower sites has been done for decision-makers to make a reasonable decision as to which sites should be given the top priority for future micro hydropower development.

Mid-fidelity simulations and comparisons of five techniques for axial induction control of a wind turbine

As wind turbines are more frequently placed in arrays, the need to understand and mitigate problems arising from their wakes has increased. When downstream turbines are in the wakes of upstream ones, the downstream turbines produce less power, require more maintenance, and have shorter lifetimes. One wake mitigation technique is known as axial induction control (AIC) and it involves derating (operating suboptimally) upstream turbines such that more energy remains in their wakes for downstream turbines to harvest. While there has been considerable research on this technique, much of it has suffered from a misunderstanding of the most important parameters in optimizing AIC. As such, the research has been largely inconclusive. Herein, we seek to rectify several perceived shortcomings of previous work by using mid-fidelity simulations to compare five different techniques for AIC at three different derate percentages against a baseline case and examining the recovery of the wake. We find that only the case with the lowest derate, 10 %, and using maximum thrust exceeds the baseline when estimating the combined power of the simulated turbine and a virtual turbine five diameters downstream and that it produced 10 % more power. Furthermore, these results help to validate previous work that concluded that the excess energy that is in the wake of a derated turbine will be at the edges of the wake unless the wake can sufficiently recover before the next downstream turbine. Finally, all together this suggests that the precise combination of derate percentage and the method used to derate turbines (i.e., the precise combination of pitch and torque controls), as well as the spacing and arrangement of turbines, must all be considered when optimizing AIC, and that substantial power gains may be possible.

Different Metabolic Roles for Alternative Oxidase in Leaves of Palustrine and Terrestrial Species

The alternative oxidase pathway (AOP) is associated with excess energy dissipation in leaves of terrestrial plants. To address whether this association is less important in palustrine plants, we compared the role of AOP in balancing energy and carbon metabolism in palustrine and terrestrial environments by identifying metabolic relationships between primary carbon metabolites and AOP in each habitat. We measured oxygen isotope discrimination during respiration, gas exchange, and metabolite profiles in aerial leaves of ten fern and angiosperm species belonging to five families organized as pairs of palustrine and terrestrial species. We performed a partial least square model combined with variable importance for projection to reveal relationships between the electron partitioning to the AOP (τa) and metabolite levels. Terrestrial plants showed higher values of net photosynthesis (AN) and τa, together with stronger metabolic relationships between τa and sugars, important for water conservation. Palustrine plants showed relationships between τa and metabolites related to the shikimate pathway and the GABA shunt, to be important for heterophylly. Excess energy dissipation via AOX is less crucial in palustrine environments than on land. The basis of this difference resides in the contrasting photosynthetic performance observed in each environment, thus reinforcing the importance of AOP for photosynthesis.

Techno-Economic Analysis of Solar Photovoltaic System for Fishery Cold Storage Based on Ownership Models and Regulatory Boundaries in Indonesia

With Indonesia’s marine resources abundance, it is appropriate for Indonesia’s economic growth to gear towards the fisheries sector. Fishery management in Indonesia is still not operating optimally due to a lack of fisheries management infrastructure. This study took place at the Fish Auction Place in Dadap Village, West Java, Indonesia. The actual problem is a fluctuation in fish catch due to seasonal factors that cause instability in fish prices and fishermen’s incomes. Furthermore, there is no cold storage for storing fish when the fish are abundant so that the quality of the fish will decrease. However, fishery cold storage is energy-intensive equipment, and there is a lack of electricity infrastructure in that coastal area. Renewable Energy Sources (RES) are the key for rural electricity because RES prices are lower, especially on-grid solar photovoltaic (PV), than fossil fuel-based. Consequently, the application of solar PV in Indonesia is still not optimal due to limited regulations. Regulations that hinder the economic value of On-grid PV system are the excess energy compensation percentage and the inverter capacity limitation. Therefore, in this study, we have modelled six regulatory scenarios related to On-grid PV system. The scenarios are how the current 65% excess energy compensation is changed to 85% and 100% (1:1 ratio) and remove the regulation regarding inverter capacity limitation. Furthermore, the ownership model of cold storage is also considered by dividing it into two models, which are commercial-based and community-based. These ownership models have different financial instruments. The simulation gives a new result by changing regulation assumptions that On-grid PV system has a lower Levelized Cost of Electricity (LCOE) than existing regulation because it can produce threefold more electricity to the utility grid with higher inverter capacity. Furthermore, the community-based cold storage rental price can be 16 % cheaper on average with all energy system topologies than the commercial-based ownership model. Then, by reducing the capital costs of solar modules and batteries in 2030, solar PV system’s LCOE will be lower by an average of 20%. It will result in an average reduction of 10% on cold storage rental prices. Finally, sensitivity analysis of the energy system is also conducted in this study. The result is that On-grid PV system is the most secure energy source against price fluctuations.

Locality values in thermal comfort embodied in traditional Indonesian houses: a literature review

This study aims to explore how traditional buildings of Indonesia adapted and responded to the current climate. Scientific publications regarding traditional houses from various regions in Indonesia were gathered to be examined the locality values in thermal comfort. The examination of the scientific publications highlighted some housing elements and arrangements that influence the thermal comfort of the houses. The building elements that affect the thermal comfort encompass lifted house on stilts; appropriate size and amount of windows; ventilated roof; selected natural material; divider arrangement; and the existence of veranda. Furthermore, as exemplified in Bali, the proper spatial arrangement between house buildings and open space influences traditional Indonesian houses’ thermal comfort. In conclusion, dealing with climate in a tropical area with high humidity can be demonstrated in those locality values without consuming excess energy for a cooling system. The significance of this study is beneficial for the development of tropical houses, which is expectedly to consider those locality values.

Multi-criteria Optimization for Parametrizing Excess Gibbs Energy Models

Thermodynamic models contain parameters which are adjusted to experimentaldata. Usually, optimal descriptions of different data sets require differentparameters. Multi-criteria optimization (MCO) is an appropriate wayto obtain a compromise. This is demonstrated here for Gibbs excess energy(GE) models. As an example, the NRTL model is applied to the three binarysystems (containing water, 2-propanol, and 1-pentanol). For each system,different objectives are considered (description of vapor-liquid equilibrium,liquid-liquid equilibrium, and excess enthalpies). The resulting MCO problemsare solved using an adaptive numerical algorithm. It yields the Paretofront, which gives a comprehensive overview of how well the given model candescribe the given conicting data. From the Pareto front, a solution that is particularly favorable for a given application can be selected in an instructedway. The examples from the present work demonstrate the benefits of theMCO approach for parametrizing GE-models.

Maternal High-Fat Diet Disturbs the DNA Methylation Profile in the Brown Adipose Tissue of Offspring Mice

The prevalence of obesity has become a threatening global public health issue. The consequence of obesity is abnormal energy metabolism. Unlike white adipose tissue (WAT), brown adipose tissue (BAT) has a unique role in nonshivering thermogenesis. Lipids and glucose are consumed to maintain energy and metabolic homeostasis in BAT. Recently, accumulating evidence has indicated that exposure to excess maternal energy intake affects energy metabolism in offspring throughout their life. However, whether excess intrauterine energy intake influences BAT metabolism in adulthood is not clear. In this study, mouse dams were exposed to excess energy intake by feeding a high-fat diet (HFD) before and during pregnancy and lactation. The histology of BAT was assessed by hematoxylin and eosin staining. The genome-wide methylation profile of BAT was determined by a DNA methylation array, and specific site DNA methylation was quantitatively analyzed by methylated DNA immunoprecipitation (MeDIP) qPCR. We found that intrauterine exposure to a high-energy diet resulted in blood lipid panel disorders and impaired the BAT structure. Higher methylation levels of genes involved in thermogenesis and fatty acid oxidation (FAO) in BAT, such as Acaa2, Acsl1, and Cox7a1, were found in 16-week-old offspring from mothers fed with HFD. Furthermore, the expression of Acaa2, Acsl1, and Cox7a1 was down-regulated by intrauterine exposure to excess energy intake. In summary, our results reveal that excess maternal energy leads to a long-term disorder of BAT in offspring that involves the activation of DNA methylation of BAT-specific genes involved in fatty acid oxidation and thermogenesis.