Main Energy Source Research Articles

Statistical Analysis of Concurrent Electron Cyclotron Harmonic and Whistler Waves Driven by ULF Waves

AbstractPlasma sheet electron precipitation to the diffuse aurora is one of the primary mechanisms of magnetospheric energy transport to the Earth’s atmosphere. Such precipitation is provided by electron resonant interactions with electron cyclotron harmonics (ECH) and whistler‐mode waves in the near‐Earth plasma sheet. ECH and whistler‐mode wave generation is traditionally attributed to two main sources of free energy: the loss‐cone anisotropy and the temperature anisotropy due to transverse electron heating during earthward convection or plasma sheet injections. This paper considers a third free energy source for ECH and whistler‐mode wave generation—the electron distribution modulation by compressional ultra‐low‐frequency (ULF) waves. We conduct statistics of ECH and whistler‐mode wave bursts associated with ULF waves and show that: (a) such bursts are mostly observed on the dawn flank, (b) 83% of events show a correlation between ECH and whistler‐mode bursts, and the rest 17% show anti‐correlation, (c) ECH and whistler‐mode wave intensities are comparable with those observed around the night‐side injection region. We investigate the main characteristics of ECH and whistler‐mode waves modulated by ULF waves and provide an empirical model for these characteristics. This model can be directly incorporated into simulation frameworks, so as to include these ULF‐modulated wave bursts in simulations of the magnetosphere‐ionosphere coupling and radiation belt dynamics.

Wave Climate Variability and Trends in Tuvalu Based on a 44‐Year High‐Resolution Wave Hindcast

AbstractWaves are one of the main causes of coastal flooding and shoreline change in low‐lying atoll nations like Tuvalu. A detailed understanding of Tuvalu’s wave climate is therefore critical for decision‐makers, coastal engineers, and disaster‐risk managers. Here, we investigate Tuvalu’s wind‐wave climate, changes due to large‐scale climate variability, and long‐term trends. A 44‐year (1979–2022) high‐resolution wave hindcast was developed using the unstructured version of the wave model Simulating Waves Nearshore (SWAN). The model resolution varied between 20 km offshore in deep water and 300 m close to shore. The model was forced with the European Centre for Medium‐Range Weather Forecasts Reanalysis v5 (ERA5) wind and boundary wave conditions. Northern and Southern Hemisphere winter months produced the largest and most powerful waves. Through the analysis of the directional wave energy spectra, we identified three main wave energy sources: (a) extratropical storms in the Southern Ocean; (b) extratropical storms in the North Pacific; and (c) easterly trade winds. Slightly positive trends in high‐frequency (∼10 s) wave energy from the east and low‐frequency (∼15 s) wave energy from the southwest were linked to an intensification of trade winds and an intensification and poleward displacement of the Southern Ocean storm belt over recent decades. The interannual variability of Tuvalu’s wave climate was strongly linked to large‐scale climate modes such as El Niño Southern Oscillation, Pacific Decadal Oscillation, and Arctic and Antarctic Oscillation. The study builds on previous research and significantly enhances the understanding of Tuvalu’s wave climate variability.

Analysis and Research on the Current Situation of Energy Use in Rural Areas of Tibet and Sichuan

This article has conducted relevant surveys on the current situation of energy use in rural areas of Linzhi City, Tibet, and Heishui County, Sichuan. The survey results show that in terms of energy sources, fuelwood accounts for the largest proportion in rural areas of Linzhi City, Tibet, accounting for 72.2% to 74.7% of energy use. Moreover, the proportion of renewable energy in rural areas is 4.5 times that of pastoral areas, and 18 times that of resource rich areas. In rural areas of Heishui County, Sichuan Province, dried cow and sheep dung is the main energy source, accounting for 79.8% of the total energy consumption. The utilization rate of renewable energy in daily life is relatively low, only 0.3%.

Composites of Co-Al hydrotalcites and carbon nanomaterials for photocatalytic H2 production

Hydrogen is considered one of the main energy sources for the near future. Numerous efforts are currently underway for the direct transformation of solar energy into H2. Hydrotalcites are two-dimensional materials whose composition can be tuned relatively easily and, by themselves or in combination with other materials, are proving to be useful for the H2 evolution reaction. In this work, composites of a Co-Al hydrotalcite with carbon spheres or nanotubes have been prepared. It has been shown that, in general, such composites improve H2 production. The influence of the nature, structure, and characteristics of the different materials on the reaction has been studied, as well as the role of each component and its mechanism. In particular, proper integration of both components and improved textural properties, as is the case of the composite with carbon spheres, leads to a yield of 3820 μmol H2 g−1 at 5 h, more than twice that obtained with hydrotalcite alone, in the presence of Ru(bpy)3Cl2 as a photosensitizer and triethanolamine as an electron donor at 450 nm. The present methodology opens the door to the preparation of other composites for the improvement of the performance of photocatalytic systems for H2 production.

Preserving Ready-to-Eat Meals Using Microwave Technologies for Future Space Programs

The crewed suborbital and space flights launched by private companies over the past three years have rejuvenated public interest in space travel, including space tourism. Ready-to-eat meals (MREs) are the main source of nutrients and energy for space travelers. It is critical that those meals are free of bacterial and viral pathogens and have adequate shelf life. The participation of private companies in space programs will create new opportunities and demand for high-quality and microbiologically safe MREs for future space travels. In this article, we provide a brief review of nutrition and energy requirements for human activities in space. We discuss the general thermal processing requirements for control of bacterial and viral pathogens in MREs and introduce advanced thermal preservation technologies based on microwaves for production of MREs with different shelf-lives under various storage conditions. We also present the latest advancements in the development of polymer packaging materials for quality preservation of thermally stabilized MREs over extended storage. Finally, we recommend future research on issues related to the sensory quality of specially formulated MREs, microbial safety of dried foods that complement high moisture MREs, and food package waste management in future space missions.

Reliability Testing of Wind Farm Devices Based on the Mean Time to Failures

Nowadays, one of the main sources of renewable energy is wind energy; therefore, a wind farm’s electricity system must be effective. As a result, wind farm (WF) equipment must continuously operate without failure or damage. To achieve this, it is necessary to regularly monitor and assess the reliability of WF systems at every point of their “life”, including design, implementation, and continued use. Three key goals are presented in the article. First, a theory of fundamental theoretical quantities that can be used in reliability and maintenance analysis is presented. The second is to put forth a theoretical reliability link between mean time to failure and WF system fitness probability (Mean Time to Failures (MTTF—Mean time between failures. MTTF = t1 + t2 + … + tn/m, where: m—the number of all failures at time T, ti—i—ty time to failure)). The third goal is to analyze the time to failure as a function of service life and to assess the dependability of the WF under consideration as a function of service life. The three-state model of the WF operation process presented in the research serves as the foundation for the analytical analysis of WF reliability. The probability of fitness (Po(t)) of the WF system and the mean time to failure were calculated based on the analytical quantities denoting this model (MTTF). The WF owner can make the best choice regarding the proper WF renewal actions with the help of knowledge of these current dependability values for an in-service WF system.

Imported Foods, Meat and other Animal Products

Food that includes nutrition and drinks is one of the basic and indispensable requirements of the body, and it represents the first aspect of the necessity of preserving the soul in terms of the side of existence, because it is the main source of energy, vitality and growth, Abstaining from eating is the act of annihilating the body in an indirect way because it the body can not continue without as it becomes weak and exhausted. As a person must take care of nourishing his body, he must also avoid every food or drink that leads to harm him. In food and drink. The Islamic Sharia has taken care of its statement, and it has established from the foundations what is known through which the ruling of what is emerging from it so that the person will be aware of his matter in his food and drink.

Impacts of energy efficiency projects in developing countries: Evidence from a spatial difference-in-differences analysis in Malawi

Spatial difference-in-differences analysis is used to study the impacts of a large-scale development intervention aimed at improving energy efficiency in Malawi. The study proposes a quasi-experimental approach that compares the changes in several outcomes of interest over time between a population that benefitted from the program (the “treated” group) and a population that did not (the “control” group). Evidence for the analysis was primarily obtained from publicly available national household survey data and nighttime lights data. Results suggest that a combination of demand-side and supply-side interventions was associated with a statistically significant increase in electricity access, a decrease in the frequency of blackouts, and a switch from traditional fuels to electricity as the main source of energy for lighting (but not for cooking). At the same time, no evidence was found suggesting that the intervention caused households to pay more for electricity. The results are consistent with an emerging view in the literature that there are synergies between energy efficiency and energy access, especially in places where the bottleneck to wider electricity access is limited electricity generation capacity rather than the cost of connecting more clients to the grid.

Spermidine Rescues Bioenergetic and Mitophagy Deficits Induced by Disease-Associated Tau Protein

Abnormal tau build-up is a hallmark of Alzheimer's disease (AD) and more than 20 other serious neurodegenerative diseases. Mitochondria are paramount organelles playing a predominant role in cellular bioenergetics, namely by providing the main source of cellular energy via adenosine triphosphate generation. Abnormal tau impairs almost every aspect of mitochondrial function, from mitochondrial respiration to mitophagy. The aim of our study was to investigate the effects of spermidine, a polyamine which exerts neuroprotective effects, on mitochondrial function in a cellular model of tauopathy. Recent evidence identified autophagy as the main mechanism of action of spermidine on life-span prolongation and neuroprotection, but the effects of spermidine on abnormal tau-induced mitochondrial dysfunction have not yet been investigated. We used SH-SY5Y cells stably expressing a mutant form of human tau protein (P301L tau mutation) or cells expressing the empty vector (control cells). We showed that spermidine improved mitochondrial respiration, mitochondrial membrane potential as well as adenosine triphosphate (ATP) production in both control and P301L tau-expressing cells. We also showed that spermidine decreased the level of free radicals, increased autophagy and restored P301L tau-induced impairments in mitophagy. Overall, our findings suggest that spermidine supplementation might represent an attractive therapeutic approach to prevent/counteract tau-related mitochondrial impairments.

Multilayer Ceramic Capacitors: An Overview of Failure Mechanisms, Perspectives, and Challenges

Along with the growing of population and social and technological improvements, the use of energy and natural resources has risen over the past few decades. The sustainability of using coal, oil, and natural gas as the main energy sources faces, however, substantial obstacles. Fuel cells, batteries, and super-capacitors have the highest energy densities, but due to their high-power density and rapid charge-discharge speed, regular dielectric capacitors are becoming more popular for pulsed power applications. High electric breakdown strength and high maximum but low-remnant (zero in the case of linear dielectrics) polarization are necessary for high energy density in dielectric capacitors. The high performance, multi-functionality, and high integration of electronic devices are made possible in large part by the multilayer ceramic capacitors (MLCCs). Due to their low cost, compact size, wide capacitance range, low ESL and ESR, and excellent frequency response, MLCCs play a significant role in contemporary electronic devices. From the standpoint of the underlying theories of energy storage in dielectrics, this paper emphasizes the significant problems and recent advancements in building extremely volumetric-efficient MLCCs. Following a thorough examination of the state-of-the-art, important parameters that may be used to improve energy-storage qualities are highlighted, such as controlling local structure, phase assembly, dielectric layer thickness, microstructure, conductivity, different failure modes, and the specific performance during the failure mechanism. The summary of some conclusions on the impending need for innovative materials and diagnostic methods in high-power/energy density capacitor applications appears at the end of the paper.

Application of a New Carbohydrate Food Quality Scoring System: An Expert Panel Report

Carbohydrate foods (≥40% energy from carbohydrates) are the main source of energy in the US diet. In contrast to national-level dietary guidance, many regularly consumed carbohydrate foods are low in fiber and whole grains but high in added sugar, sodium, and/or saturated fat. Given the important contribution of higher-quality carbohydrate foods to affordable healthy diets, new metrics are needed to convey the concept of carbohydrate quality to policymakers, food industry stakeholders, health professionals, and consumers. The recently developed Carbohydrate Food Quality Scoring System is well aligned with multiple key healthy messages on nutrients of public health concern from the 2020-2025 Dietary Guidelines for Americans. Two models are described in a previously published paper: one for all non-grain carbohydrate-rich foods (e.g., fruits, vegetables, legumes) known as the Carbohydrate Food Quality Score-4 (CFQS-4), and one for grain foods only known as the Carbohydrate Food Quality Score-5 (CFQS-5). These CFQS models provide a new tool that can guide policy, programs, and people towards improved carbohydrate food choices. Specifically, the CFQS models represent a way to unify and reconcile diverse ways to describe different types of carbohydrate-rich foods (e.g., refined vs. whole, starchy vs. non-starchy, dark green vs. red/orange) and make for more useful and informative messaging that better aligns with a food's nutritional and/or health contributions. The present paper's aims are to show that the CFQS models can inform future dietary guidelines and help support carbohydrate food recommendations with other health messages aimed at promoting foods that are nutrient-dense, fiber-rich, and low in added sugar.

Pathways for deep decarbonization of the Brazilian iron and steel industry

Steel production is one of the major sources of greenhouse gas (GHG) emissions. Brazil is one of the largest steel producers in the world and its main energy sources for steel production are coal, electricity, and charcoal. The latter shows a peculiarity of Brazil in relation to other countries: the use of biomass. This study has developed an optimization bottom-up model describing the steel industry to explore pathways for the decarbonization of the Brazilian steel industry. The model minimizes the mitigation costs, considering a set of measures (energy efficiency technologies and innovative production routes), constrained by the availability of raw materials and the diffusion of new technologies. In addition, the model stands out by incorporating crucial elements for a circular bioeconomy strategy: scrap and biomass supply, as well biomass-based production technologies. We developed four scenarios: business-as-usual (BAU) and three mitigation scenarios aligned with different GHG mitigation goals in 2050: 0% (no emission increase scenario – NIS); 42% (sustainable development scenario – SDS) and 88% (deep sustainable development scenario – SDS+). Results show that GHG mitigation in the short term can be achieved by the adoption of well known technologies (energy efficiency, charcoal-based BF-BOF, and EAF) at negative mitigation costs (between −35.3 and - 1.5 $/tCO2e). Innovative routes play a key role in reaching emission goals but increase the mitigation costs until 2050 (between 23.4 and 43.4 $/tCO2e). Smelting reduction with charcoal is present in all scenarios, reaching up to 24% of steel production in 2050 (SDS+). Direct reduction (DR) is applied to reach more ambitious levels of GHG mitigation in SDS and SDS+. In SDS, DR with natural gas is implemented in 2029, reaching its higher share of production in 2050 (21%). In SDS + natural gas has a transition role. It starts to be used in DR in 2025, increasing until 2043, when hydrogen begins to replace it. By 2050, charcoal becomes the main energy source in all decarbonization scenarios. The results and insights provided by this study can help policymakers towards decarbonization.

Crude oil, international trade and political stability: Do network relations matter?

The aim of this work is to investigate the different implications in terms of political stability that a high oil dependency has in both oil-exporting and oil-importing countries. We employ network analysis to understand which countries are most connected in the global crude oil trade, and central in the intermediation of the flows. Then, we use this information to estimate the effects of oil dependency on political stability on a panel of 155 countries over the period 1995–2019, by means of a simultaneous-quantile regression model. Our findings corroborate the resource curse hypothesis in relation to oil-exporting countries, especially linking this outcome to the emergence of rent-seeking behaviours. Interestingly, we find that a different type of resource curse hypothesis – related to the indirect endowment of oil resources – also affects intermediary countries. As for oil importers, we find that countries that are heavily dependent on oil as the main energy source are largely exposed to geopolitical turmoil and risk to import political instability together with oil.

Human Milk: Fast Determination of Docosahexaenoic Acid (DHA)

Human milk provides all the nutrients required by babies during the first six months of their life. Human milk lipids represent the main source of energy, contributing almost 50% of the total energy content. Additionally, fatty acids ensure the correct development of children in the prenatal, postnatal, and infant phases. Docosahexaenoic acid (DHA) is essential for visual and cognitive development, and its presence during childhood can affect long-term health. This study aimed to optimize and validate a methodology for the direct determination of DHA in human milk. We used 20 samples of human milk from lactating women living in the city of Itu, São Paulo, who attended Basic Health Units from September 2019 to September 2020, and a sample of certified reference material from the National Institute of Standards and Technology. The proposed methodology consists of a validated mixed transesterification process without prior lipid extraction, optimized by factorial design. This methodology can be successfully used in human milk samples as it is both precise and accurate. The values of DHA in the sampled milks were similar to those in European countries and lower than those in Asian countries due to diet.

Low carbohydrate high fat-diet in real life assessed by diet history interviews

BackgroundLow carbohydrate high fat (LCHF) diet has been a popular low carbohydrate diet in Sweden for 15 years. Many people choose LCHF to lose weight or control diabetes, but there are concerns about the effect on long-term cardiovascular risks. There is little data on how a LCHF diet is composed in real-life. The aim of this study was to evaluate the dietary intake in a population with self-reported adherence to a LCHF diet.MethodsA cross-sectional study of 100 volunteers that considered themselves eating LCHF was conducted. Diet history interviews (DHIs) and physical activity monitoring for validation of the DHIs were performed.ResultsThe validation shows acceptable agreement of measured energy expenditure and reported energy intake. Median carbohydrate intake was 8.7 E% and 63% reported carbohydrate intake at potentially ketogenic levels. Median protein intake was 16.9 E%. The main source of energy was dietary fats (72.0 E%). Intake of saturated fat was 32 E% and cholesterol was 700 mg per day, both of which exceeded the recommended upper limits according to nutritional guidelines. Intake of dietary fiber was very low in our population. The use of dietary supplements was high, and it was more common to exceed the recommended upper limits of micronutrients than to have an intake below the lower limits.ConclusionsOur study indicates that in a well-motivated population, a diet with very low carbohydrate intake can be sustained over time and without apparent risk of deficiencies. High intake of saturated fats and cholesterol as well as low intake of dietary fiber remains a concern.

Whether the Air Transport is Going through the Difficulties: Evidence from Dynamic Changes in Brent Oil Prices

In 2020, the outbreak of COVID-19 caused a sharp drop in international crude oil prices. The outbreak of the Russian Ukrainian conflict in 2022 has also had a great impact on the fluctuation of international crude oil prices. So far as an important source of energy, the fluctuation of crude oil price is associated with the entire financial market. Therefore, this paper try to find how the air transport industry will going through the dynamic changes of its main source of energy——crude oil. Then the data of Brent oil price and air transportation industry index are selected from six months earlier before the Russian Ukrainian conflict broke out, used for constructing VAR model and ARMA-GARCH model with their logarithmic sequences. Through testing and observing the constructed Var model and ARMA-GARCH model, find the impact of international crude oil price changes on the yield and volatility of air transportation industry, so that the air transport industry can acquire the initiative of energy source.

Introducing TIGRESS-NCR. I. Coregulation of the Multiphase Interstellar Medium and Star Formation Rates

Massive, young stars are the main source of energy that maintains multiphase structure and turbulence in the interstellar medium (ISM), and without this “feedback” the star formation rate (SFR) would be much higher than is observed. Rapid energy loss in the ISM and efficient energy recovery by stellar feedback lead to coregulation of SFRs and the ISM state. Realistic approaches to this problem should solve for the dynamical evolution of the ISM, including star formation and the input of feedback energy self-consistently and accurately. Here, we present the TIGRESS-NCR numerical framework, in which UV radiation, supernovae, cooling and heating processes, and gravitational collapse are modeled explicitly. We use an adaptive ray-tracing method for UV radiation transfer from star clusters represented by sink particles, accounting for attenuation by dust and gas. We solve photon-driven chemical equations to determine the abundances of hydrogen (time dependent) and carbon/oxygen-bearing species (steady state), which then set cooling and heating rates self-consistently. Applying these methods, we present high-resolution magnetohydrodynamics simulations of differentially rotating local galactic disks representing typical conditions of nearby star-forming galaxies. We analyze ISM properties and phase distributions and show good agreement with existing multiwavelength galactic observations. We measure midplane pressure components (turbulent, thermal, and magnetic) and the weight, demonstrating that vertical dynamical equilibrium holds. We quantify the ratios of pressure components to the SFR surface density, which we call the feedback yields. The TIGRESS-NCR framework will allow for a wide range of parameter exploration, including in low-metallicity systems.

The Low‐Altitude Ionosphere of the Ice Giant Planets

AbstractThe study of atmospheric electricity of the lower stratosphere and upper troposphere of the ice giant planets can help to understand several physical phenomena such as cloud formation, lightning generation, aerosols growth, or chemical composition. At these depths, galactic radiation is the main energy source able to ionize the atmospheric constituents and to produce a low altitude ionospheric layer that can be similar in magnitude to the upper ionosphere produced by solar radiation and auroral electrons. The presence of aerosols affects the ion‐neutral chemistry by capturing electrons and ions depending on the aerosol size and number density. Here, we present a new one dimensional ionospheric model of Uranus and Neptune able to calculate the number densities of electrons and ions as well as the charging of aerosols between 100 Pa and 4 × 105 Pa. Since the results depends upon the amount and size of the atmospheric aerosols, as well as on the flux of the incoming cosmic radiation, several aerosol models, solar‐cycle conditions, and the effect of the intrinsic magnetic field are considered.

Dietary patterns and fertility status in men: Mediterranean diet does make a difference in ameliorating the rise in male infertility problems due to changing lifestyle

Dietary patterns and fertility status in men: Mediterranean diet does make a difference in ameliorating the rise in male infertility problems due to changing lifestyle

Gas microturbine as a main source of energy for industrial laundry – feasibility study

Gas microturbine as a main source of energy for industrial laundry – feasibility study