Energy Generation Processes Research Articles

Sustainable energy generation processes in the deserts of solar-rich countries

A sustainable energy generation system in solar-rich countries can establish the process of desert community development in these areas. To test the validity of this hypothesis, potential assessment of deserts’ solar power is carried out. The results reveal that considerable amounts of electric power and potable water can be produced locally at these deserts sites. In this paper, the basic needs of a sizeable desert community are identified; their total energy requirements are estimated and then the capability of available solar potential to meet these energy needs is calculated. A sustainable energy generation model is devised to attain the objective of power generation and potable water production. The processes of solar power generation, desalination and storage systems are built in the proposed model. The sustainable development process is based on the utilization of renewable energy, self-contained nature of energy generation system and environment-friendly nature of power and water production.

Prolonged Rapamycin treatment led to beneficial metabolic switch

Prolonged Rapamycin treatment led to beneficial metabolic switch

Catalytic Carbon Gasification: Review of Observed Kinetics and Proposed Mechanisms or Models - Highlighting Carbon Bulk Diffusion

Carbon gasification is an important reaction in industrial processes, energy generation processes, and diesel soot reduction. The observed kinetics are briefly reviewed, both in non porous and porous materials. The cases of combustion of graphite, coal, char, coke and diesel fuel soot are compared. A review of the proposed mechanisms is done with an emphasis in carbon bulk diffusion, using Fick's Law to articulate the carbon bulk diffusion step with the other steps. The relevance of the Hedvall effect and the Tammann temperature in transition metals is addressed, including a discussion about the relation between mechanistic models and phenomenological models.

Experimental Needs and Opportunities in Nuclear Astrophysics

Nuclear Astrophysics is a wide field covering the nuclear physics basis of nucleosynthesis and energy generation processes in quiescent and explosive stellar burning environments. This presentation will focus on the experimental basis of key reactions in different phases of quiescent stellar burning, discussing the experimental and theoretical basis of presently adopted reaction rates. New experimental facilities are being planned and implemented and may provide important information for reducing the overall uncertainties of these rates which will improve the simulations of late stellar evolution providing an improved basis for predicting the seed material for subsequent explosive processes.

Hydrogen from Sunlight Water Splitting: Is It Our Future?

Environmental pollution and the growing need to find new sources of energy are some of the challenges of our century. The unstoppable growth of population, the increasing energy needs of emerging countries, and the foreseeable shortage of fossil fuels in a few years, make imperative to develop new energy generation processes and, in this regard, nanotechnology and the development of new nanomaterials will play a decisive role for the future of the planet.

Design of Optimal Experiments for Parameter Estimation of Microalgae Growth Models

Mathematical models are expected to play a pivotal role for driving microalgal production towards a profitable process of renewable energy generation. To render models of microalgae growth useful tools for prediction and process optimization, reliable parameters need to be provided. This reliability implies a careful design of experiments that can be exploited for parameter estimation. In this paper, we provide guidelines for the design of experiments with high informative content that allows an accurate parameter estimation. We study a real experimental device devoted to evaluate the effect of temperature and light on microalgae growth. On the basis of a mathematical model of the experimental system, the optimal experiment design problem was solved as an optimal control problem. E-optimal experiments were obtained by using two discretization approaches namely sequential and simultaneous. The results showed that an adequate parameterization of the experimental inputs provided optimal solutions very close to those provided by the simultaneous discretization. Simulation results showed the relevance of determining optimal experimental inputs for achieving an accurate parameter estimation.

The Preparation of Silicon and Aluminum Alkali Extracts from Fused Turkish Coal Fly Ashes

Large quantities of solid waste generated from households, offices, shops, markets, restaurants, public institutions, industrial installations, water works and sewage facilities, construction and demolition sites, and agricultural activities. It causes environmental problems such as groundwater contamination, atmospheric and water pollution, etc. when it is disposed in landfills. Fly ash is the by-product of the coal combustion process for energy generation and remains a major problem in many parts of the world. The large amounts of fly ash are produced and the annual production of it has continued to increase. The disposal of fly ash may cause long-term adverse environmental effects. In this study, the silicon and aluminum in two different Turkish fly ashes (Afsin-Elbistan and Catalagzı) were activated by fusion with sodium hydroxide. The obtained leachates were analyzed for silicon and aluminum content by inductively coupled plasma optical emission spectrometry (ICP-OES). In addition, the mineralogical and chemical properties of these fly ashes are compared.

An investigation on the relationship between solar irradiance signal from ERBS and 8B solar neutrino flux signals from SNO

In the present work an attempt has been made to investigate statistical association between solar neutrino flux data (both D2O and Salt data) collected from Sudbury Neutrino Observatory and solar irradiance data detected by Earth Radiation Budget Satellite. To serve the present purpose we have used the Multifractal Detrended Cross Correlation Analysis (MF-DCCA) based on Detrended Fluctuation Analysis (MF-X-DFA) method and the Detrending Moving Average Analysis (MF-X-DMA) which explores the long term power-law cross correlations between above two pairs of data sets. Investigation also has been made to find the frequency and time dependent local phase relationship in each pair of data sets using continuous wavelet transform (CWT) based Semblance Analysis. The Semblance Analysis reveals that there exists positive phase correlation as well as negative phase correlation between solar irradiance and D2O data at different time sub-intervals. This type of mixed phase correlation is also experienced between solar irradiance and Salt data at different time sub-intervals. The causal relationship between the D2O and the solar irradiance time series and that between Salt and solar irradiance time series have been revealed using Singular Spectral Analysis (SSA). Calculations indicate that possibly the present solar neutrino flux data (both D2O and Salt data) is supportive to predict the solar irradiance data but may not the vice versa which in turn suggests that the variability of nuclear energy generation process inside the Sun may influence the solar activity.

Cost-benefit analysis – leakage reduction by rehabilitating old water pipelines: Case study of Oslo (Norway)

Water saving is not just the responsibility of the consumer. While demand-side management prescribes several good practices for water-consumers, the supplier also understands that leakage reduction on its part is a more effective mode of saving large quantities of water, by having to abstract, treat and supply less. It is not just water which is saved, but money spent on chemicals and energy expended on treatment and pumping. The economic aspect apart, this also means that there are possibilities of significant reductions of environmental impacts upstream in the chemicals production and energy generation processes. However, it is not an easy task to perform a comprehensive cost-benefit analysis, by taking into account all the direct and indirect costs and benefits. Benefits besides are not just multi-pronged but also distributed over time. In this paper, the author compares the direct costs incurred in rehabilitating old water pipelines in Oslo, with the direct benefits of leakage reduction which accrue therefrom, for the period 2011–2020. Avoided greenhouse gas emissions by virtue of savings in energy and chemicals are compared with the greenhouse gas emissions which occur due to the rehabilitation operations. It is seen that it often becomes difficult to justify rehabilitation economically, if the direct and indirect monetary benefits in addition those accruing from leakage reduction alone are not taken into consideration. Interestingly, the net savings in GHG emissions are significant, even over the 10-year study period.

Insulin resistance in regulation of metabolism

This paper highlights the main causes leading the development of insulin resistance (IR), its mechanisms, and the role it plays in living activity. The analysis of the available literature gives reason to believe that the source of IR is the constant requirement for plastic and high-energy compounds to be mobilized from the body's internal reserves. The mechanisms underlying the development IR involve all organ systems that interact between themselves and thereby govern the origin and evolution of insulin resistance via regulation of the energy generation and consumption processes. This concept is in excellent agreement with the laws of thermodynamics. The vital activity is based on the principle of continuous variations of IR. This inference provides a basis for addressing a number of clinical problems.

Thermal pretreatment to improve methane production of Scenedesmus biomass

Research into the development of renewable and sustainable fuels has been a major concern during last decades. Microalgae, as a potential resource, have gained great attention for energy purposes. In this context, anaerobic digestion seems to be the most direct energy generation process. Nevertheless, the efficiency of this process is hampered due to the hard cell wall of some microalgae. In order to enhance its anaerobic biodegradability, the present research investigated the effect of thermal pretreatment at two temperatures (70 and 90 °C) applied to Scenedesmus biomass. No differences were detected in terms of organic matter or ammonium release upon the two tested temperatures. Nevertheless, a different fact was observed for their anaerobic biodegradability. While raw and pretreated at 70 °C microalgae attained 22–24% anaerobic biodegradability, microalgae pretreated at 90 °C achieved anaerobic biodegradability of 48%. Even though similar profiles were obtained for both temperatures along the pretreatment period, the damage caused in the cell wall at 90 °C seemed to be greater and rendered this substrate readily degradable for anaerobic digestion.

Forms, crosstalks, and the role of phospholipid biosynthesis in autophagy.

Autophagy is a highly conserved cellular process occurring during periods of stress to ensure a cell's survival by recycling cytosolic constituents and making products that can be used in energy generation and other essential processes. Three major forms of autophagy exist according to the specific mechanism through which cytoplasmic material is transported to a lysosome. Chaperone-mediated autophagy is a highly selective form of autophagy that delivers specific proteins for lysosomal degradation. Microautophagy is a less selective form of autophagy that occurs through lysosomal membrane invaginations, forming tubes and directly engulfing cytoplasm. Finally, macroautophagy involves formation of new membrane bilayers (autophagosomes) that engulf cytosolic material and deliver it to lysosomes. This review provides new insights on the crosstalks between different forms of autophagy and the significance of bilayer-forming phospholipid synthesis in autophagosomal membrane formation.

Atomic layer deposition for electrochemical energy generation and storage systems

Clean renewable energy sources (e.g., solar, wind, and hydro) offers the most promising solution to energy and environmental sustainability. On the other hand, owing to the spatial and temporal variations of renewable energy sources, and transportation and mobility needs, high density energy storage and efficient energy distribution to points of use is also critical. Moreover, it is challenging to scale up those processes in a cost-effective way. Electrochemical processes, including photoelectrochemical devices, batteries, fuel cells, super capacitors, and others, have shown promise for addressing many of the abovementioned challenges. Materials with designer properties, especially the interfacial properties, play critical role for the performance of those devices. Atomic layer deposition is capable of precise engineering material properties on atomic scale. In this review, we focus on the current state of knowledge of the applications, perspective and challenges of atomic layer deposition process on the electrochemical energy generation and storage devices and processes.

Optimal Energy Commitments with Storage and Intermittent Supply

We formulate and solve the problem of making advance energy commitments for wind farms in the presence of a storage device with conversion losses, mean-reverting price process, and an autoregressive energy generation process from wind. We derive an optimal commitment policy under the assumption that wind energy is uniformly distributed. Then, the stationary distribution of the storage level corresponding to the optimal policy is obtained, from which the economic value of the storage as the relative increase in the expected revenue due to the existence of storage is obtained.

Genome-Wide Analysis of Biotin Biosynthesis in Eukaryotic Photosynthetic Algae

Biotin is a cofactor responsible for carbon dioxide transfer in several carboxylase enzymes, which play a significant role in various metabolic reactions such as fatty acid synthesis, branched chain amino acid catabolism, and gluconeogenesis. Biotin is also involved in citric acid cycle, which is the process of biochemical energy generation during aerobic respiration. Though the function of biotin in the growth of algae has been extensively investigated, little is known about the biosynthetic routes of biotin in the algal kingdom. In the present study, 44 biotin biosynthesis-related genes were identified from 14 eukaryotic photosynthetic algal genomes by BLASTP and TBLASN programs. A comprehensive analysis was performed to characterize distribution, phylogeny, structure domains, and coevolution patterns of those genes. Forty-four biotin biosynthesis-related enzymes (BBREs) were found to be distributed in three groups: 7-keto-8-aminopelargonic acid synthase, diaminopelargonic acid synthase/dethiobiotin synthetase, and biotin synthase. Structure domains were considerably conserved among the subfamilies of BBREs. The intramolecular coevolutionary sites are widely distributed in biotin synthase. The present study provides new insights into the origin and evolution of biotin biosynthetic pathways in eukaryotic photosynthetic algae. Furthermore, the characterization of biotin biosynthesis-related genes from algae will promote the identification and functional studies of BBREs.

Reducing emissions of noxious substances produced in heat energy generation process to environment

The problems of reducing emissions of noxious substances while generating heat and electrical energy are scrutinized. A method is proposed for combined operation of a gas-turbine thermal and electric power plant and a heat pump, which helps reduce CO2, NOx, and SO2 emissions to the atmosphere as well as discharges of process waters into water bodies. This article is of interest to engineers and technologists dealing with issues of energy saving and environment protection.

The Transcriptional Response of Listeria monocytogenes during Adaptation to Growth on Lactate and Diacetate Includes Synergistic Changes That Increase Fermentative Acetoin Production

The organic acids lactate and diacetate are commonly used in combination in ready-to-eat foods because they show synergistic ability to inhibit the growth of Listeria monocytogenes. Full-genome microarrays were used to investigate the synergistic transcriptomic responses of two L. monocytogenes strains, H7858 (serotype 4b) and F6854 (serotype 1/2a), to these two organic acids under conditions representing osmotic and cold stress encountered in foods. Strains were exposed to brain heart infusion (BHI) broth at 7°C with 4.65% water-phase (w.p.) NaCl at pH 6.1 with (i) 2% w.p. potassium lactate, (ii) 0.14% w.p. sodium diacetate, (iii) the combination of both at the same levels, or (iv) no organic acids as a control. RNA was extracted 8 h after exposure, during lag phase, to capture gene transcription changes during adaptation to the organic acid stress. Significant differential transcription of 1,041 genes in H7858 and 640 genes in F6854 was observed in at least one pair of the 4 different treatments. The effects of combined treatment with lactate and diacetate included (i) synergistic transcription differences for 474 and 209 genes in H7858 and F6854, respectively, (ii) differential transcription of genes encoding cation transporters and ABC transporters of metals, and (iii) altered metabolism, including induction of a nutrient-limiting stress response, reduction of menaquinone biosynthesis, and a shift from fermentative production of acetate and lactate to energetically less favorable, neutral acetoin. These data suggest that additional treatments that interfere with cellular energy generation processes could more efficiently inhibit the growth of L. monocytogenes.

Solar Energy Demand (SED) of Commodity Life Cycles

The solar energy demand (SED) of the extraction of 232 atmospheric, biotic, fossil, land, metal, mineral, nuclear, and water resources was quantified and compared with other energy- and exergy-based indicators. SED represents the direct and indirect solar energy required by a product or service during its life cycle. SED scores were calculated for 3865 processes, as implemented in the Ecoinvent database, version 2.1. The results showed that nonrenewable resources, and in particular minerals, formed the dominant contribution to SED. This large share is due to the indirect solar energy required to produce these resource inputs. Compared with other energy- and exergy-based indicators, SED assigns higher impact factors to minerals and metals and smaller impact factors to fossil energetic resources, land use, and nuclear energy. The highest differences were observed for biobased and renewable energy generation processes, whose relative contribution of renewable resources such as water, biomass, and land occupation was much lower in SED than in energy- and exergy-based indicators.

Multiparticle Sintering Dynamics: From Fractal-Like Aggregates to Compact Structures

Multiparticle sintering is encountered in almost all high temperature processes for material synthesis (titania, silica, and nickel) and energy generation (e.g., fly ash formation) resulting in aggregates of primary particles (hard- or sinter-bonded agglomerates). This mechanism of particle growth is investigated quantitatively by mass and energy balances during viscous sintering of amorphous aerosol materials (e.g., SiO(2) and polymers) that typically have a distribution of sizes and complex morphology. This model is validated at limited cases of sintering between two (equally or unequally sized) particles, and chains of particles. The evolution of morphology, surface area and radii of gyration of multiparticle aggregates are elucidated for various sizes and initial fractal dimension. For each of these structures that had been generated by diffusion limited (DLA), cluster-cluster (DLCA), and ballistic particle-cluster agglomeration (BPCA) the surface area evolution is monitored and found to scale differently than that of the radius of gyration (moment of inertia). Expressions are proposed for the evolution of fractal dimension and the surface area of aggregates undergoing viscous sintering. These expressions are important in design of aerosol processes with population balance equations (PBE) and/or fluid dynamic simulations for material synthesis or minimization and even suppression of particle formation.

Development of new material for the environmental-friendly energy generation processes

The aim of this study was to develop a new material which has high hydrogen storage capacity and hydrogen absorption/desorption rate. This material, which is based on cobalt powder onto which palladium was chemically deposited can be used in environmentally friendly energy generation processes, thus ensuring preventive protection of human health. Hydrogen absorption was investigated using differential scanning calorimetry (DSC) and by measuring hydrogen pressure under isothermal and non-isothermal conditions in a chamber containing either pure cobalt powder either cobalt powder onto which palladium was chemically deposited (Co-0.003 Pd). The mechanism of hydrogen absorption has been described. It was noticed that palladium catalyses hydrogen absorption by dissociating the adsorbed H2 molecules into H atoms more rapidly on its own atoms than on cobalt ones. The catalysis of dissociation of H2 molecules enabled hydrogen absorption into Co-0.003 Pd powder to occur at lower temperatures. The results of this study enable integration of technological and public health investigation in order to ensure preventive protection of human health through enviromental protection.