Variation Of Total Energy Research Articles

Analysis of energy access and impact of modern energy sources in unelectrified villages in Uttar Pradesh

Bringing access to modern energy sources to the poorest in society is a key goal of many policymakers, businesses and charities, but in order to be a success projects and schemes must be founded on accurate data. We undertook a survey of energy demand and usage patterns in households in unelectrified villages in Uttar Pradesh, India to assess access to and utilisation of energy sources for lighting and cooking. The times of usage were recorded and analysed and the effect on usage patterns of transitioning from traditional to modern energy sources is assessed. We quantify the cost and greenhouse gas emissions of current energy use in order to provide a benchmark of potential mitigation through the use of renewable energy technologies: a typical household with kerosene lamps only for lighting spends INR 3243 (US$50.67) and emits 381 kgCO2eq per year; households with modern cooking energy spend 17% more through increased usage, but emit 28% less greenhouse gases compared to those with traditional stoves only. Cell phone ownership was found to be 50% amongst adults. We use demographic and utilisation data to construct an hourly demand profile of basic electricity demand extrapolated to each month of the year, and present an example of aspirational demand assess the impact of desirable appliances. A Monte Carlo simulation is used to highlight the daily and seasonal variation in total energy and power demand. A hybrid system, with solar power and battery storage meeting daytime demand and higher-capacity diesel- or biomass-powered generation meeting the remainder during evening peaks and winter months, would satisfy demand most effectively.

Effect of surface pre-treatment on surface characteristics and adhesive bond strength of aluminium alloy

In this work aluminium alloy surfaces have been subjected to three different methods of surface pre-treatments such as solvent degreasing, FPL (Forest Products Laboratory) etching and priming using an epoxy based primer. The treated surfaces were evaluated for surface energy, contact angle, surface topography, surface roughness and adhesive strength characteristics. The influence of surface pre-treatments on the variation of polar, dispersive and total surface energy of the surfaces is addressed. A wettability test was performed on the surfaces using an epoxy adhesive in order to assess the influence of the pre-treatment techniques on substrate/adhesive interaction. Theoretical work of adhesion values for the various pre-treated surfaces were calculated using the contact angle data and further tested experimentally by adhesive bond strength evaluation by tensile testing of a single lap aluminium-epoxy-aluminium assembly. The method of surface pre-treatment showed a profound effect on the surface topography and roughness by AFM. This study reveals that a combination of high surface energy and high surface roughness of the substrate along with good wettability of the adhesive contributed to the highest joint strength for the aluminium alloy through the FPL etching pre-treatment.

Energies and wave functions of an off-centre donor in hemispherical quantum dot: Two-dimensional finite difference approach and ritz variational principle

Eigenvalues equation solutions of a hydrogen-like donor impurity, confined in a hemispherical quantum dot deposited on a wetting layer and capped by an insulating matrix, are determined in the framework of the effective mass approximation. Conduction band alignments at interfaces between quantum dot and surrounding materials are described by infinite height barriers. Ground and excited states energies and wave functions are determined analytically and via one-dimensional finite difference approach in case of an on-center donor. Donor impurity is then moved from center to pole of hemispherical quantum dot and eigenvalues equation is solved via Ritz variational principle, using a trial wave function where Coulomb attraction between electron and ionized donor is taken into account, and by two-dimensional finite difference approach. Numerical codes developed enable access to variations of donor total energy, binding energy, Coulomb correlation parameter, spatial extension and radial probability density with respect to hemisphere radius and impurity position inside the quantum dot.

Interface and Strain Energy Revolution Texture Map To Predict Structure and Optical Properties of Sputtered PbSe Thin Films.

The preferred growth orientation of the sputtered lead selenide (PbSe) thin films on Si(100) substrates was thermodynamically simulated and calculated on the basis of the density functional theory. The results showed that the total free energy variation during the grain growth is dominated by the interface and strain energy minimization under certain conditions, indicating that the preferred growth orientation and related optical properties of the PbSe thin films can be effectively modified by these two energy variations. Thermodynamically, the PbSe[200] and PbSe[220] preferred orientations are obtained when the interface and strain energy minimization dominate the total free energy variation, respectively. A texture map related to the interface and strain energy revolution was obtained, which can be used to predict the structure and optical properties of the sputtered PbSe thin films, and its applicability was confirmed by the real X-ray diffraction and Fourier transform infrared spectroscopy experimental results of four midfrequency sputtered PbSe thin films with designed thickness and microstrain deposited on Si(100) substrates.

Ab initio calculations of structural, elastic, electronic and thermodynamic properties of the cerium filled skutterudite CeRu4P12 under the effect of pressure

AbstractThe paper presents an investigation on crystalline, elastic and electronic structure in addition to the thermodynamic properties for a CeRu4P12 filled skutterudite device by using the full-potential linear muffin-tin orbital (FP-LMTO) method within the generalized gradient approximations (GGA) in the frame of density functional theory (DFT). For this purpose, the structural properties, such as the equilibrium lattice parameter, bulk modulus and pressure derivatives of the bulk modulus, were computed. By using the total energy variation as a function of strain we have determined the independent elastic constants and their pressure dependence. Additionally, the effect of pressure P and temperature T on the lattice parameters, bulk modulus, thermal expansion coefficient, Debye temperature and the heat capacity for CeRu4P12 compound were investigated taking into consideration the quasi-harmonic Debye model.

Energy-Harvesting Mechanisms for UAV Flight by Dynamic Soaring

Dynamic Soaring is a flying technique which extracts energy from an environment where wind gradients form, with the potential to increase the endurance of small unmanned vehicles. The feasibility to use dynamic soaring flight is questioned here; it requires the identification of energy-extraction mechanisms as well as accurate understanding of the way energy-harvesting performances are governed by trajectory constraints, vehicle characteristics and environment conditions. A three-dimensional energy-neutral trajectory is derived out of a specified optimization problem. Characteristic phases of flight are evidenced out of an overall closed trajectory. Simplified equations are used to evidence the physics behind energy transfers. Finally, overall energy-harvesting balance is studied through local variations of total energy along the path.

Impact of dietary fiber energy on the calculation of food total energy value in the Brazilian Food Composition Database

Dietary fiber (DF) contributes to the energy value of foods and including it in the calculation of total food energy has been recommended for food composition databases. The present study aimed to investigate the impact of including energy provided by the DF fermentation in the calculation of food energy. Total energy values of 1753 foods from the Brazilian Food Composition Database were calculated with or without the inclusion of DF energy. The energy values were compared, through the use of percentage difference (D%), in individual foods and in daily menus. Appreciable energy D% (⩾10) was observed in 321 foods, mainly in the group of vegetables, legumes and fruits. However, in the Brazilian typical menus containing foods from all groups, only D%<3 was observed. In mixed diets, the DF energy may cause slight variations in total energy; on the other hand, there is appreciable energy D% for certain foods, when individually considered.

Accurate Element of Compressive Bar considering the Effect of Displacement

By constructing the compressive bar element and developing the stiffness matrix, most issues about the compressive bar can be solved. In this paper, based on second derivative to the equilibrium differential governing equations, the displacement shape functions are got. And then the finite element formula of compressive bar element is developed by using the potential energy principle and analytical shape function. Based on the total potential energy variation principle, the static and geometrical stiffness matrices are proposed, in which the large deformation of compressive bar is considered. To verify the accurate and validity of the analytical trial function element proposed in this paper, a number of the numerical examples are presented. Comparisons show that the proposed element has high calculation efficiency and rapid speed of convergence.

An Approach to Identify Site Response Directivity of Accelerometer Sites and Application to the Iranian Area

In recent years, several workers have found numerous cases of sites characterised by significant azimuthal variation of dynamic response to seismic shaking. The causes of this phenomenon are still unclear, but are possibly related to combinations of geological and geomorphological factors determining a polarisation of resonance effects. To improve their comprehension, it would be desirable to extend the database of observations on this phenomenon. Thus, considering that unrevealed cases of site response directivity can be “hidden” among the sites of accelerometer networks, we developed a two-stage approach of data mining from existing strong motion databases to identify sites affected by directional amplification. The proposed procedure first calculates Arias Intensity tensor components from accelerometer recordings of each site to determine mean directional variations of total shaking energy. Then, at the sites where a significant anisotropy appears in ground motion, azimuthal variations of HVSR values (spectral ratios between horizontal and vertical components of recordings) are analysed to confirm the occurrence of site resonance conditions. We applied this technique to a database of recordings acquired by accelerometer stations in the Iranian area. The results of this investigation pointed out some sites affected by directional resonance that appear to be correlated to the orientation of local tectonic lineaments, these being mostly transversal to the direction of maximum shaking. Comparing Arias Intensities observed at these sites with theoretical estimates provided by ground motion prediction equations, the presence of significant site amplifications was confirmed. The magnitude of the amplification factors appear to be correlated to the results of HVSR analysis, even though the pattern of dispersion of HVSR values suggests that while high peak values of spectral ratios are indicative of strong amplifications, lower values do not necessarily imply lower amplification factors.

Vibration analysis of laminated plates with various boundary conditions using extended Kantorovich method

In this study, an extended Kantorovich method, employing multi-term displacement functions, is applied to analyze the vibration problem of symmetrically laminated plates with arbitrary boundary conditions. The vibration behaviors of laminated plates are determined based on the variational principle of total energy minimization and the iterative Kantorovich method. The out-of-plane displacement is represented in the form of a series of a sum of products of functions in x and y directions. With a known function in the x or y directions, the formulation for the variation of total potential energy is transformed to a set of governing equations and a set of boundary conditions. The equations and boundary conditions are then numerically solved for the natural frequency and vibration mode shape. The solutions are verified with available solutions from the literature and solutions from the Ritz and finite element analysis. In most cases, the natural frequencies compare very well with the reference solutions. The vibration mode shapes are also very well modeled using the multi-term assumed displacement function in the terms of a power series. With the method used in this study, it is possible to solve the angle-ply plate problem, where the Kantorovich method with single-term displacement function is ineffective.

Structural, elastic, electronic and thermodynamic properties of uranium filled skutterudites UFe4P12: First principle method

We present a theoretical study of structural, elastic, thermodynamic, and electronic properties of the uranium filled skutterudite UFe4P12. We use the full-potential linear muffin–tin orbital (FP-LMTO) method in which the local density approximation (LDA) is used for the exchange-correlation (XC) potential. The lattice parameter at equilibrium, the bulk modulus, its pressure derivative, the elastic constants and the band structure energy of the filled skutterudite UFe4P12 are calculated and systematically compared to available theoretical and experimental data. Herein, we use the total energy variation as function of strain technique to determine independent elastic constants and their pressure dependence. Furthermore, using quasi-harmonic Debye model with phonon effects, the effect of pressure P and temperature T on the lattice parameter, bulk modulus, thermal expansion coefficient, Debye temperature and the heat capacity of UFe4P12 are investigated for the first time. Band structure of UFe4P12 indicates a tendency of forming a pseudo-gap that appears above the Fermi level at Γ point. This is a unique characteristic of skutterudite, especially when a single phosphorous p-band crosses the Fermi level. The crossing band is, indeed, pushed down by the repulsion of U f-resonance states.

Variable Star Symbols for Seismicity Plots

Online Material: Maps of seismicity and cities; test sheet; list of earthquakes; Fortran 77 code. At least since Mallet (1858) seismicity maps have been a way of showing earthquake activity, but, because earthquake size varies greatly, it is difficult to provide an accurate representation of the spatial variation of total seismic energy or moment release. The most common approach, using for each earthquake a single geometric figure of varying size, creates substantial overlap between large symbols. To reduce overlap and provide a more distinctive gradation, I propose a family of symbols in which size and shape vary together, from polygonal to star shaped as their size increases. Two functions determine how symbol size and shape vary with value, and even a simple parametrization gives considerable flexibility in symbol design. Tests show that, given an appropriate key, the symbol value can be estimated to within better than 5% of the range covered. Symbolization in seismicity maps is challenging. Using identical symbols plotted at the epicenters (or, in a cross section, the hypocenters) shows where there are more or fewer earthquakes but not how (say) moment release is distributed. This can be done by spatially smoothing the amount of energy or moment release and contouring the result (e.g., Allen et al. , 1965), but this in turn removes fine details. Most seismicity maps use a simple geometrical figure, usually a circle or square, to symbolize for each earthquake and vary its size with the earthquake magnitude. The interior of each symbol can be filled with a color to denote depth (or, in Web displays, recency of occurrence). One problem with this approach is that one large symbol can easily cover many small ones. Some seismicity maps use two geometrical figures, one (often a scaled circle) for events less than some magnitude and another …

The inhibition of folylpolyglutamate synthetase (folC) in the prevention of drug resistance in Mycobacterium tuberculosis by traditional Chinese medicine.

Tuberculosis (TB) is an infectious disease caused by many strains of mycobacteria, but commonly Mycobacterium tuberculosis. As a possible method of reducing the drug resistance of M. tuberculosis, this research investigates the inhibition of Folylpolyglutamate synthetase, a protein transcript from the resistance association gene folC. After molecular docking to screen the traditional Chinese medicine (TCM) database, the candidate TCM compounds, with Folylpolyglutamate synthetase, were selected by molecular dynamics. The 10,000 ps simulation in association with RMSD analysis and total energy and structural variation defined the protein-ligand interaction. The selected TCM compounds Saussureamine C, methyl 3-O-feruloylquinate, and Labiatic acid have been found to inhibit the activity of bacteria and viruses and to regulate immunity. We also suggest the possible pathway in protein for each ligand. Compared with the control, similar interactions and structural variations indicate that these compounds might have an effect on Folylpolyglutamate synthetase. Finally, we suggest Saussureamine C is the best candidate compound as the complex has a high score, maintains its structural composition, and has a larger variation value than the control, thus inhibiting the drug resistance ability of Mycobacterium tuberculosis.

Possible inhibitor from traditional Chinese medicine for the β form of calcium-dependent protein kinase type II in the treatment of major depressive disorder.

Recently, an important topic of major depressive disorder (MDD) had been published in 2013. MDD is one of the most prevalent and disabling mental disorders. Consequently, much research is being undertaken into the causes and treatment. It has been found that inhibition of the β form of calcium/calmodulin-dependent protein kinase type II (β-CaMKII) can ameliorate the disorder. Upon screening the traditional Chinese medicine (TCM) database by molecular docking, sengesterone, labiatic acid, and methyl 3-O-feruloylquinate were selected for molecular dynamics. After 20 ns simulation, the RMSD, total energy, and structure variation could define the protein-ligand interaction. Furthermore, sengesterone, the principle candidate compound, has been found to have an effect on the regulation of emotions and memory development. In structure variation, we find the sample functional group of important amino acids make the protein stable and have limited variation. Due to similarity of structure variations, we suggest that these compounds may have an effect on β-CaMKII and that sengesterone may have a similar efficacy as the control. However labiatic acid may be a stronger inhibitor of β-CaMKII based on the larger RMSD and variation.

Interaction mechanisms of screw dislocations with and twin boundaries in Mg

Molecular dynamics simulations were carried out to investigate the interactions between screw partials and the and twin boundaries in Mg. In the twin, the interaction was attractive and the partials were absorbed readily in the boundary. In the twin, however, they passed through the twin boundary because of a repulsive interaction when a large applied strain was applied. The total energy including the dislocation core energy and the twin boundary energy was found to be similar before and after the absorption of the partials in the twin boundary, while it increased upon the absorption of the partial in the twin boundary. The origins of the total energy variations are discussed from a crystallographic viewpoint.

Influence of the bucket geometry on the Pelton performance

The increasing share of hydropower in world electricity production requires the development of standardized and optimized design procedures leading to increasingly higher efficiency values. To date, despite a certain amount of support from computational fluid dynamics, Pelton turbines are still characterized by semiempirical design criteria that do not make it possible to optimize the jet–bucket interaction in order to maximize turbine performance. Based on an analysis of particle flow tracks, this paper presents a hybrid Eulerian–Lagrangian method to investigate the influence of bucket geometry on the Pelton efficiency at two different operating conditions. Jet–bucket interaction was numerically analyzed by means of a traditional mesh-based numerical approach, using a transient multi-phase homogeneous model. Subsequently, the numerical results were integrated using a predictor–corrector algorithm, combining a fourth order Adams-Bashforth method as predictor and a fourth order Adams-Moulton method as corrector, in order to determine the fluid particle trajectories on the rotating buckets. The particle flow tracks were analyzed in detail to evaluate the single-particle performance in terms of discharged kinetic energy, momentum variation, and total energy variation during the jet–bucket interaction. Moreover, on the basis of the particle discharging position, the contribution of the different bucket areas to the total torque of the turbine was investigated to determine the time-depending influence of the bucket geometry on the turbine energy exchange and to suggest possible design solutions for improving bucket performance.

A simple procedure to extend the Gauss method of determining orbital parameters from three to N points

A simple procedure is developed to determine orbital elements of an object orbiting in a central force field which contribute more than three independent celestial positions. By manipulation of formal three point Gauss method of orbit determination, an initial set of heliocentric state vectors ${\bf r}_i$ and $\dot{\bf{r}}_i$ is calculated. Then using the fact that the object follows the path that keep the constants of motion unchanged, I derive conserved quantities by applying simple linear regression method on state vectors ${\bf r}_i$ and $\dot{\bf{r}}_i$. The best orbital plane is fixed by applying an iterative procedure which minimize the variation in magnitude of angular momentum of the orbit. Same procedure is used to fix shape and orientation of the orbit in the plane by minimizing variation in total energy and Laplace Runge Lenz vector. The method is tested using simulated data for a hypothetical planet rotating around the sun.

First-principles study of structural stabilities, elastic and electronic properties of transition metal monocarbides (TMCs) and mononitrides (TMNs)

The structural stabilities, elastic and electronic properties of 5d transition metal mononitrides (TMNs) XN with (X = Ir, Os, Re, W and Ta) and 5d transition metal monocarbides (TMCs) XC with (X = Ir, Os, Re and Ta) were investigated using the full-potential linear muffin-tin orbital (FP-LMTO) method, in the framework of the density functional theory (DFT) within the local density approximation (LDA) for the exchange correlation functional. The ground state quantities such as the lattice parameter, bulks modulus and its pressure derivatives for the six considered crystal structures, Rock-salt (B1), CsCl (B2), zinc-blend (B3), Wurtzite (B4), NiAs (B81) and the tungsten carbides (Bh) are calculated. The elastic constants of TMNs and TMCs compounds in its different stable phases are determined by using the total energy variation with strain technique. The elastic modulus for polycrystalline materials, shear modulus (G), Young's modulus (E), and Poisson's ratio (ν) are calculated. The Debye temperature (θD) and sound velocities (vm) were also derived from the obtained elastic modulus. The analysis of the hardness of the herein studied compounds classifies OsN – (B4 et B81), ReN – (B81), WN – (B81) and OsC – (B81) as superhard materials. Our results for the band structure and densities of states (DOS), show that TMNs and TMCs compounds in theirs energetically and mechanically stable phase has metallic characteristic with strong covalent nature Metal–Nonmetal elements.

Room-Temperature Si Etching in NO/F2 Gases and the Investigation of Surface Reaction Mechanisms

We have been investigating a plasmaless Si chemical dry etching in NO/F2 gas mixtures using the F produced by the exothermic reaction of F2 + NO → FNO + F at room temperature. The effect of the change in the flow rate ratio of NO and F2, fNO/fF2, on the etch rate, the chemical bonding structures, and the surface morphology was measured by laser microscopy, Fourier transform infrared spectrometer, scanning electron microscopy, and scanning white light interferometry and results were compared with the calculated F flux. Total energy variations and their changes in chemical bonding structures before and after the reactions of molecules in the gas phase and the Si surface were considered using the molecular orbital (MO) method. On the basis of the MO calculation using a Si(100)-2×1 cluster model, F was necessary to form a dangling bond at the surface of Si that would trigger subsequent chemical reactions of Si with F2, NO, F, or FNO. The etch rate and surface roughness increased with the addition of NO up to the fNO/fF2 = 1.0 to 1.5 and then decreased due to the reduction of F flux in the gas phase together with the presence of the Si-NO and the Si-FNO bonds that would block the interaction of Si with F2 and F.

Stability of the austenite lattice of a high-nickel iron-based alloy toward the martensitic transformation

First-principles calculations of the variation of the total energy of a ferromagnetic Fe-31.2% Ni alloy upon bainitic transformation are presented. The problem of the loss of stability of the fcc lattice of iron alloys is discussed to show that the fcc lattice is mechanically stable in this alloy.