The Management of Agriculture Plastic Waste in the Framework of Circular Economy. Case of the Almeria Greenhouse (Spain)

In recent decades, ecosystems have suffered diverse environmental impacts caused by anthropogenic activities, including the dumping of plastic waste. This situation has prompted the European Union to introduce a new policy based on the circular economy. In this study, the present state and future perspectives on the generation and treatment of plastic waste in the intensive agriculture of Almeria (Spain) are analyzed. This activity generates 1503.6 kg·ha−1·year−1, on average, of plastic waste with an approximate treatment cost of 0.25 €/kg. The present study shows that the volume of plastic waste from intensive agriculture in Almeria is constantly increasing (48,948.2 tons in 2020/21) and it is suggested that the current management system does not meet the needs of the sector. Although it presents great opportunities for improvement under the framework of the circular economy. Furthermore, this work reports a direct relationship between the price of the raw materials needed for the production of plastic and the volume of recycled plastics. For this reason, it would be advisable for the administration to consider the implementation of a tax rebate system for the sector and specifically when the petroleum derivatives used to manufacture plastic are less expensive, and the recycling option is not so attractive.

Application of the Multi-Spectral Correlated-k Distribution Model to Multi-Dimensional Rectangular Enclosure Gas Radiation Calculations

The Multi-Spectral Correlated-k distribution model (MSCk) is an amelioration of the widely used Ck model. In the MSCk model, the breakdown of correlation assumption used in the original Ck model for non-uniform media is overcome by introducing the clustering of scaling functions. The principle of MSCk model is to group together wavenumbers with respect to the spectral scaling functions—defined as the ratio between spectral absorption coefficients in distinct states—so that the correlation assumption can be considered as exact over the corresponding intervals of wavenumbers. Until now, validations of the MSCk model in 0D and 1D test cases have already been performed in the previous work (Andre, F., Hou, L., Roger, M. and Vaillon, R., 2014. The multispectral gas radiation modeling: A new theoretical framework based on a multidimensional approach to k-distribution methods. Journal of Quantitative Spectroscopy and Radiative Transfer, 147, pp.178–195; Andre, F., Hou, L. and Solovjov, V.P., 2016. An Exact Formulation of k-Distribution Methods in Non-Uniform Gaseous Media and its Approximate Treatment Within the Multi-Spectral Framework. Journal of Physics: Conference Series, 676(1)). However, its application to multi-dimensional configurations (much closer to industrial applications) has not been conducted. Accordingly, in the present paper, we focus our attention on the application of the MSCk model to Multi-dimensional calculations.

A Linearized Model of FID Signal for Increasing Proton Magnetometer Precision

A linearized model of frequency measurement for the Free Induction Decay (FID) signal is proposed to increase the Proton Magnetometer (PM) precision. First, the nonlinear model of frequency measurement is set up according to the characteristic of the FID signal. Then, according to the error analysis of the MCFM method, the model is linearized on the condition of precision requirement. Furthermore, to reduce the nonlinear error caused by approximate treatment and the trigger time error caused by the random noise, the Least Squares (LS) method is adopted to estimate the slope of the linearized model, and the frequency to be measured is the inverse of the slope. Finally, a PM Prototype is made to verify the effectiveness of the proposed method. Experimental results show that the precision of frequency measurement is obviously increased if the proposed method is adopted for the noised sine signal. Moreover, the RMSD and the NPSD of magnetic-field measurement are about 0.13 nT and 80 pT/Hz1/2, respectively if the proposed method is adopted by PM, which is better than the comparison method.

Three median relations of target azimuth in one dimensional equidistant double array

Before this paper, the authors have obtained the tangent median relation by using the trigonometric function equation. In this paper, on the basis of the linear positioning solution of one-dimensional equidistant double-base linear array, by proper approximate treatment of the strict solution, and by using the direction finding solution of single base path difference, the sinusoidal median relation of azimuth angle at three stations of the linear array is obtained. By using the sinusoidal median relation, the arithmetic mean solution of azimuth angle at three stations is obtained. All these results reveal the intrinsic correlation between the azimuth angles of one-dimensional linear array.

Study of the Half-Diagonal Two-Body Density Matrix of Model Nuclear Matter

The half-diagonal two-body density matrix ρ_{2h}/i(r1,r2,r') plays a central role in most theoretical treatments of the propagation of ejected nucléons and their final state interactions (FSI) in the nuclear medium. In this work based on the analysis of Ristig and Clark, we present the results of a Fermi hypernetted-chain calculation ρ_{2h}/i(r1,r2,r') for infinite symmetrical nuclear matter using a Jastrow-correlated model. The dependence of ρ_{2h} on the variables involved has been investigated in detail. Significant departures from ideal Fermi gas behavior in certain domains demonstrate the importance of short-range correlations. A comparison of our results with the predictions of Silver's approximation to ρ_{2h}, which has been employed in some treatments of FSI, reveals certain shortcomings of this approximation. The Fermi hypernetted-chain results obtained here will serve as a key input to an approximate treatment of FSI in inclusive quasielastic electron scattering from nuclear matter.

Approximate treatment of the Dirac equation with scalar and vector potentials of rectangular shapes

The Dirac equation with scalar potential Us(r) and fourth component of vector po­ tential Uv(r) is considered in the case of the rectangular shapes of these potentials with the same radius R and approximate analytic expressions are derived for the single-particle energy of bound states in certain cases. The results obtained with these expressions are compared with the corresponding "exact" results obtained by solving the eigenvalue equa­ tion numerically.It is found that very good results are obtained for the ground state and for quite a wide range of values of R with one of the proposed expressions. Even the corresponding non-relativistic version of this expession, has not been derived before, to our knowledge.

nvestigation of Hydrocarbon Contaminants Destructing Microorganisms as a Method of Water Purification Intensifying

Increased hydrocarbon pollution of the natural environment and water bodies in recent decades has prompted the search for ways to reduce anthropogenic pollution. A number of modern environmental biotechnologies provide for the process of microbial introduction that is introduction of microorganisms with a useful function into the natural environment (soil and water bodies).The paper presents the results of laboratory studies on the rate of absorption of hydrocarbons by various microorganisms, the study of their hydrophilic/hydrophobic/adhesive properties, as well as the results of the search for a correlation between the degree of hydro/repellence of the cell surface and the rate of consumption of polluting hydrocarbon. Experiments on microbial separation of petroleum products from sand and Teflon surface made it possible to establish the possibility of this kind of destruction and determine the approximate treatment time depending on temperature. In terms of the degree of hydrophobicity, the bacteria strains involved in the decomposition process are placed in a series of activities that allows more successfully establishing the ratios of microorganisms-destructors in spatial communities for biological treatment of wastewater.

A systematic study of the effect of short range correlations on the occupation numbers of the shell model orbits in light nuclei

The role of short-range correlations on the depletion of the Fermi sea is studied in light nuclei.The short range correlations are considered in an approximate treatment allowing a systematic study of nuclei in the region 4 < A < 40. The "natural orbital" representation is used for the determination of the occupation probabilities of the shell model orbits of the ground state wave function. The depletion of the nuclear Fermi sea appears to be, on the average, about 32%.

Modeling of Chloride Distribution in Cement-Based Materials with Neumann Boundary Condition

The nonstable transport of chloride in cement-based materials, including diffusion, convection, and chloride binding, is described as a general form of Fick’s law. Inspired by the heat transport of concrete, the second boundary condition called the Neumann boundary condition is considered in the chloride transport of concrete. The theoretical deduction of one-dimensional chloride distribution with the Neumann boundary condition is performed, while a virtual boundary is introduced to carry out the approximate treatment. Finally, the comparison between the general Dirichlet boundary condition and the present Neumann boundary condition and the influence of the thickness of the virtual boundary as well as the influence of the water-cement ratio (w/c) are discussed.