About the Simultaneous Co-Existence of Instantaneous and Retarded Interactions in Classical Electrodynamics

In this paper it is proved that, contrary to the results found by A.E. Chubykalo and S.J. Vlaev (Int. J. Mod. Phys. A 14, 3789 (1999)), the retarded electric and magnetic fields for an uniformly accelerated charge exactly satisfy Maxwell equations (ME). Furthermore it is shown that ME are correctly written in the usual form with the partial derivatives and thus not, as proposed by Chubykalo and Vlaev, with the total derivatives.Comment: 7 pages, to be published in Int. J. Mod. Phys.

A Novel Device for the Soil Sterilizing in Sustainable Agriculture

In this paper a machine that performed the soil sterilization has been designed. The soil is cut and put in a loading hopper and downloaded in a rotating cylinder placed on the machine. The fins located inside the rotating cylinder performed the crushing and the mixing of the soil. Each soil particle through the temperature field ranged between 290–1900° C for 3–5 min and a preset output soil temperature of 130–140° C is reached and discharged downward. It maintained the process temperature long enough, to allow the elimination of the infesting organisms located in the considered soil

Numerical Simulation of a Cryogenic Plant for the Cooling of Mashed Grapes

A numerical model of cryo-maceration plant for mashed grapes has been realized to simulate the rapid cooling process for mashed grapes according to the number of nozzles enabled to inject CO2, to their flow and temperature of CO2 injected. ANSYS CFX program was used and two geometries have been considered with the axis of each nozzle orthogonal and parallel to the flow direction. Different boundary conditions have been considered. For the models have been considered the most burdensome condition

Stability Analysis of Self-propelled Hydrodynamic Irrigation Machines Used for Food Industry Crops

Some critical limit conditions for the stability of the self-propelled hydrodynamic irrigation machine used for food industry crops, have been studied, and experimental and numerical tests have been carried out for their determination. The strength forces necessary for the machine overturn have been calculated by a computer code realized in Matlab R2019a, and the corresponding values are listed as function of the soil slope angle ψ of the weight W and the pipeline strength force., With this aim, different operative conditions for the considered machine have been examined so that the pipeline strength force, under the following conditions: water filled pipeline of and empty pipeline;dry and wet soil. By analyzing the data measured in the open field, on a considered machine with a coil diameter of 3 m, the different contributes to the total rewinding strength have been examined during the considered tests. Further, it has been possible to deduce that by changing; only the value of the water pressure, the total value of the rewinding strength force increased by 100 daN, which is clearly due; to the changing pressure which increases the stiffness of the polyethylene pipeline. Moreover, other very dangerous limit conditions were determined during the rewinding phase of the pipeline on overflooded soil (also due to a rain storm), with a pipeline completely unwound on the soil and sunk into it. In these critical conditions, it has been noted that, to perform the operating phase, it is possible to reach a very high T value, which can cause the machine overturning even for ψ = 0 (horizontal case)

Design and development of a new press for grape marc

The purpose of this research was to determine the optimal geometry of a variable pitch conical helicoid to be used in a pressing machine for grape pomace, also known as grape marc. This study attempted to understand if the optimized geometry of the considered helicoid after every pitch resulted in volume decrease DVc, equal to that obtained during the pressing phase of grape pomace DVp, using an optimized membrane press. The conical helicoid with variable pitch was replaced in a machine that offered continuous pressing of grape pomace using a cylindrical helicoid with constant pitch (constant pressure distribution, not optimized, along the cochlea axis). As this was a machine already available in the market, the overall dimensions were already established-5.95 m in length and 1.5 m in width. The pressure distribution p1 and volume change DVp, obtained during the grape pomace pressing phase in the optimized membrane press (producing high-quality wine) was taken into consideration in this research. Furthermore, the optimized pressure distribution p1 was applied in seven phases during the pressing process, and a consequent volume change value DVp was obtained for each phase. Therefore, this study determined the geometry of the variable pitch conical helicoid, which, after every pitch, resulted in volume changing DVc that was similar to the volume changing DVp obtained by the optimized membrane press. For this scope, calculations were realized using the Mathematica 10 program code, which, on being assigned the overall dimensions, slope angle of the helicoid, and volume for the first pitch value, determined the radius and pitch values of the helicoid, total volume, and volume change DVc. It was also noted that by appropriately varying the geometric parameters (taper and pitch of the helicoid), different options of pressure distribution on grape pomace can be obtained, thus enabling improvement and optimization of product quality

Agricultural waste-based composts exhibiting suppressivity to diseases caused by the phytopatogenic soil-borne fungi Rhizoctonia solani and Sclerotinia minor

On-farm composting is an efficient, environmentally safe and cost-effective process for recycle vegetable residues into productive cycles. Benefits of these composts could include their ability to mediate soil-borne plant pathogen suppression with a significant impact on eco-friendly crop management. In this work, on-farm composts were assayed for ability to control, both in vitro and in vivo, damping-off causing pathogens Rhizoctonia solani and Sclerotinia minor. Tomato and escarole-derived compost was the most suppressive and, furthermore, together with that derived from artichoke wastes, exhibited multi-suppressive activity. Compost communities, characterized at metabolic and global level by Biolog system, microbial counting, CO2-release and FDA hydrolysis rate, play a major role in compost-based biological control. The complete biotic inactivation by autoclaving composts, has, in fact, reduced or eliminated their ability in pathogen suppression. Solid state 13C-CPMAS-NMR spectroscopy revealed that spectrum areas typical for phenolic C, as well as methoxyl C, may be associated to suppressivity mechanism(s). These evidences suggested that the ecological relatioships between organic carbon molecular distribution and microbial structure may contribute to discriminate suppressive composts from null and conducive ones. Nutritional microniches in the composts can have profound effects on the community functions, including those linked to the suppressiveness

Fuzzy-assisted ultrafiltration of wastewater from milk industries

The whey is a by-product rich in organic substances; the system, as conceived, is self-learning

Cardiological findings in acromegaly

Acromegaly involves cardiovascular complications mostly due to the presence of hypertension, diabetes and atherosclerosis. However the appearance of cardiac decompensation and arrhythmias in the absence of predisposing factors tends to support the hypothesis of a specific myocardiopathy caused by excess GH. In order to assess the existence and course of subclinical cardiac alterations, 8 acromegaly patients were examined: 4 males and 4 females aged 31-56 with GH levels of 24-70 ng/ml (M + CD X 47 ± 16) and no cardiovascular symptoms. One of the patients had moderate hypertension and 2 reduced glucose tolerance. The basal ECG showed sporadic ventricular extrasystoles in 2 cases and alterations compatible with left ventricular hypertrophy in another, while the effort ECG produced an asymptomatic depression of the ST segment in the hypertensive patient. The chest X-ray was normal in all cases. The echocardiography study investigated: the thickness of the interventricular septum (IVS = 13.9 ± 2.8 mm), the thickness of the posterior wall of the left ventricle (LPW = 10.6 ± 2.9 mm), the septum/posterior wall ratio (IVS/LPW = 1.3 ± 0.2 the diastolic diameter (DD = 15.4 ± 11.4 mm), the fraction of shortening (FS = 39.1 ± 14.5%), the ejection fraction (EF = 64.1 ± 18.4%) and revealed asymmetrical septal hypertrophy in 3 cases, concentric hypertrophy in another two. In two cases the DD and EF were distinctly altered. The patients were re-examined 2-4 years after surgical or radiation treatment. GH levels (M ± SD = 10.3 ± 10.1 ng/ml) were normal in 4 cases and still high, though lower in another two. The remaining two patients had borderline GH levels with high Sm-C. The ECG and chest X-ray were unchanged while echocardiography revealed a significant deterioration in heart function as far as DD (56.4 ± 10.8 mm, p < 0.05) were concerned with frankly pathological results in 4 and 3 cases respectively. These data confirm the view that most acromegalic patients present subclinical abnormalities in cardiac function and that the evolution of these is slightly influenced by the reduction in GH and Sm-C. levels. In fact, while the persistence of high GH and Sm-C. levels may explain the progression of cardiac alterations in some cases, it does not in others. It is also emphasised that echocardiography appears to be the most sensitive non-invasive technique for the diagnosis and follow-up of cardiac involvement in acromegaly

Fluid-structure interaction modeling applied to peristaltic pump flow simulations

In this study, fluid-structure interaction (FSI) modeling was applied for predicting the fluid flow in a specific peristaltic pump, composed of one metallic roller and a hyperelastic tube pumping a viscous Newtonian fluid. Hyperelastic material dynamics and turbulence flow dynamics were coupled in order to describe all the physics of the pump. The commercial finite element software ABAQUS 6.14 was used to investigate the performance of the pump with a 3D transient model. By using this model, it was possible to predict the von Mises stresses in the tube and flow fluctuations. The peristaltic pump generated high pressure and flow pulses due to the interaction between the roller and the tube. The squeezing and relaxing of the tube during the operative phase allowed the liquid to have a pulsatile behavior. Numerical simulation data results were compared with one cycle pressure measurement obtained from pump test loop data, and the maximum difference between real and simulated data was less than 5%. The applicability of FSI modeling for geometric optimization of pump housing was also discussed in order to prevent roller and hose parts pressure peaks. The model allowed to investigate the effect of pump design variations such as tube occlusion, tube diameter, and roller speed on the flow rate, flow fluctuations, and stress state in the tube