4,703 research outputs found
Remarks on the paper “Mass and energy-capital conservation equations to Forecast monthly oil price”
The mass and energy-capital conservation equations have been used at the beginning of 2013 to forecast the monthly oil price up to December 2013. The approach of the interest rates has employed an interest rate equal to the arithmetic average between the prime and the discount rates. The present short communication comments the comparison between the forecast made during the middle of the 2013 and the real oil prices, as registered today, at the beginning of 2014
Mass and Energy-Capital Conservation Equations to Forecast Monthly Oil Price
Mass and the energy-capital conservation equations are employed to study the time evolution of the mass of oil and the oil price evolution with time of the resources sold to the market in case of no-accumulation and no-depletion of the resources; i.e. when the resources are extracted and sold to the market at the same mass flow rate. The time evolution of the monthly oil price is studied from 1994 until 2012, investigating the detailed forecast resulting from the application of the present theory. The oil price can be reasonably forecasted using the prime and the discount rate interests as extreme limits
A New Theory to Forecast the Price of Non Renewable Energy Resources with Mass and Energy-Capital Conservation Equations.
The mass and energy-capital conservation equations are employed to study the time evolution of mass and price of non-renewable energy resources, extracted and sold to the market, in case of no-accumulation and no-depletion; i.e. when the resources are extracted and sold to the market at the same mass flow rate. The Hotelling rule for non-renewable resources, i.e. an exponential increase of the price at the rate of the current interest multiplied the time, is shown to be a special case of the general energy-capital conservation equation when the mass flow rate of extracted resources is unity. The mass and energy-capital conservation equations are solved jointly to investigated the time evolution of the extracted resources. The parameter PIFE, “Price Increase Factor of Extracted resources”, is the difference between the interest rate of capital, typically the inflation rate, and the mass flow rate of extraction of non-renewable resources. The price of the extracted resources increases if PIFE is greater than zero, i.e. the mass flow rate of extraction is smaller than the inflation rate. The price is constant if PIFE is zero, i.e. the mass flow rate of extraction is equal to the inflation rate. The price is decreasing with time if PIFE is smaller than zero, i.e. the mass flow rate of extraction is greater than the inflation rate. The price of selling resources varies with time according to the relation between the parameters PIFE and PIFS, “Price Increase Factor of Selling resources”, which is the difference between the extraction rate and the interest rates of selling resources, prime or discount rate. The price of selling resources increases with time if the initial price is greater than CIPS, “Critical Initial Price of Sold resources”, which depends on the initial price of extracted resources, the interest rate of non-extracted resources, and the difference between PIFS and PIFE or is greater than CIPES, “Critical Initial Price Extreme of Selling resources”, which depends on the initial price of extracted resources, the interest rate of non-extracted resources, and PIFS. The price of selling resources increases temporarily with time if the interest rates of non-extracted and extracted resources are equal, i.e. PIFE is equal to PIFS, and the initial price is greater than CIPES, “Critical Initial Price Extreme of Selling resources”. The price evolutions of the difference between selling and extracted resources are investigated according to the relation between extraction rate and interest rate of extracted and selling resources. The price difference increases with time if PIFS is greater than PIFE of the extracted resources and the initial price is greater than the critical price of selling resources, which depends on the initial price of extracted resources and the interest rate of non-extracted and extracted resources. The price difference decreases with time if PIFS is greater than PIFE and the initial price is smaller than the critical price of selling resources. The other cases are discussed extensively in the paper. The price evolution of non-renewable resources versus the consumption rate is investigated with the aim of constructing the energy supply curve. The case studied is without accumulation nor depletion of the resources and the mass and energy-capital conservation equations are solved under the condition of the same mass flow rate of extraction and sale. The energy supply curve of extracted resource is dependent on the new parameter, RINE, “Rate of Interest of Non-extracted resources on the Extraction rate”. The energy supply curve of selling resource is dependent on the new parameter, RISE, “Rate of Interest of Sold resources on the Extraction rate”, in case the rate of interest of non-extracted resources, rN, is nil. The energy supply curve of selling resources is dependent also on two dimensionless parameters, “Dimensionless Critical Initial Price of Sold resources”, i.e. DCIPS, and “Dimensionless Critical Initial Price Extreme of Sold resources”, i.e. DCIPES. The energy supply curve of selling resources is investigated under different relations between three parameters, i.e. extraction rate and interest rates of extracted and selling resources. New trends are observed in the economic market of non-renewable energy resources. The energy supply curve of the difference between selling and extracted resource is dependent on two dimensionless parameters, “Critical Initial Price Difference”, i.e. CIPD, and “Critical Extreme of the Initial Price Difference”, i.e. CEIPD. The price difference between selling and extracted resources is investigated versus the dimensionless mass flow rate of extraction. The evolution is dependent on four parameters: RINE, RISE, DCIPS, and DCIPES
The interaction-strength interpolation method for main-group chemistry: benchmarking, limitations, and perspectives
We have tested the original interaction-strength-interpolation (ISI)
exchange-correlation functional for main group chemistry. The ISI functional is
based on an interpolation between the weak and strong coupling limits and
includes exact-exchange as well as the G\"orling-Levy second-order energy. We
have analyzed in detail the basis-set dependence of the ISI functional, its
dependence on the ground-state orbitals, and the influence of the
size-consistency problem. We show and explain some of the expected limitations
of the ISI functional (i.e. for atomization energies), but also unexpected
results, such as the good performance for the interaction energy of
dispersion-bonded complexes when the ISI correlation is used as a correction to
Hartree-Fock.Comment: 20 pages, 20 figure
Density functional theory for strongly interacting electrons
We present an alternative to the Kohn-Sham formulation of density functional
theory for the ground-state properties of strongly interacting electronic
systems. The idea is to start from the limit of zero kinetic energy and
systematically expand the universal energy functional of the density in powers
of a "coupling constant" that controls the magnitude of the kinetic energy. The
problem of minimizing the energy is reduced to the solution of a strictly
correlated electron problem in the presence of an effective potential, which
plays in our theory the same role that the Kohn-Sham potential plays in the
traditional formulation. We discuss several schemes for approximating the
energy functional, and report preliminary results for low-density quantum dots.Comment: Revised version, to appear in Phys. Rev. Let
Detection of a dry-frozen boundary inside Martian regolith
The present work investigates the time oscillations of the temperature at several depths of a Martian soil analogue made of two layers of different physical properties. The maximum temperature-time oscillation inside the Martian soil analogue, DT, and its derivative with depth, d(DT)/dz or DDT, can be analysed to understand the presence of a boundary between dry and frozen soil. The maximum temperature-time oscillation, DT, reduces by about one order of magnitude at the boundary between dry and frozen soil if a frozen layer is present. The reduction of DT at the boundary between two dry soils with different porosity is much smaller. DDT decreases by more than one order of magnitude at the boundary between dry and frozen soil if a frozen layer is present. The reduction of DDT at the boundary between two dry soils with different porosity is much smaller. (C) 2008 Elsevier Ltd. All rights reserved
Two new differential equations of turbulent dissipation rate and apparent viscosity for non-Newtonian fluids.
A new equation for the dissipation rate of turbulent kinetic energy is derived exactly in conservative form for a Generalized Newtonian Fluid (GNF). The transport equations for mass, momentum, and turbulent kinetic energy are written along to the transport equation for the shear rate. A new transport equation for the apparent viscosity is derived assuming the viscosity as dependent only on the shear rate. The assumption is of incompressible two-dimensional GNF flow
Development of a new screening tool for cyber pornography. Psychometric properties of the Cyber Pornography Addiction Test (CYPAT)
Objective: Internet pornography addiction typically involves viewing, downloading and trading online pornography or engagement in adult fantasy role-play. There are some well-validated inventories measuring perceived addiction to internet pornography but these instruments are often too long for a functionally use and fast scoring. The aim of this study was to evaluate the psychometric properties of the cyber pornography addiction test (CYPAT), a new, brief, screening measure for assessing cyber pornography.Method: Participants of this study completed the CYPAT, the CPUI, the TAS-20 and the FACES-IV. Descriptive statistics were calculated and Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) were applied.Results: Cronbach's alpha coefficient suggested excellent reliability of the measure. Results of this study revealed also good construct, convergent and divergent validity.Conclusions: CYPAT is a brief self-report screening scale composed of 11 items scored on a five-point Likert scale with good psychometrics properties. The implications of these findings for future theoretical and empirical research in this field are discusse
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