Electrochemical Preparation of Fe0.5CoNiCuSnx Medium Entropy Alloys and Their Corrosion Properties

The exploration of efficient preparation methods and corrosion-resistant medium entropy alloys (MEAs) has attracted significant attentions in recent years. In this paper, powdery Fe0.5CoNiCuSnx (x=0, 0.05, 0.08, and 0.1) MEAs were prepared by the one-step electrochemical reduction of metal oxides in molten Na2CO3-K2CO3 using a Ni11Fe10Cu oxygen-evolution inert anode. The effects of Sn on the structures, morphologies, and corrosion behaviors of the prepared MEAs were systematically investigated. The electrolytic MEAs exhibited a single face-centered cubic phase at x≤0.05, and the CuSn-rich phase would be segregated in the alloys at 0.08≤x≤0.1. Moreover, increasing Sn reduced the particles size of MEAs, and Sn improved the corrosion resistance of MEAs in 0.5 M H2SO4, 1 M KOH, and 3.5% NaCl solutions. The electrolytic MEA(Sn0.05) exhibited the best corrosion resistance, which had the corrosion current densities of 3.7×10-5 A/cm2 (0.5 M H2SO4), 1.2×10-5 A/cm2 (1 M KOH), and 1.6×10-5 A/cm2 (3.5 wt% NaCl) at room temperature. Overall, this paper not only provides a green approach to preparing Sn-containing MEAs, but also offers an efficient way to control structures and morphologies, thereby improving the corrosion resistance.

Qualitative and Numerical Research of Body Motion in a Resisting Medium

Proposed activity presents next stage of the study of the problem of the plane-parallel motion of a rigid body interacting with a resistant medium through the frontal plane part of its external surface. Under constructing of the force acting of medium, we use the information on the properties of medium streamline fl w around in quasistationarity conditions (for instance, on the homogeneous circular cylinder input into the water). The medium motion is not studied, and we consider such problem in which the characteristic time of the body motion with respect to its center of masses is comparable with the characteristic time of motion of the center of masses itself.

APPLIED MODEL OF METHODS FOR RECLAMATION OF SALT LAND

Based on the available achievements in the field of methodology, natural sciences and research in the field of environmental management, a method is proposed for constructing an applied model for the development of saline lands as "activity-natural objects" of the «Soils", including cognitive activities, transforming activities, transformations natural materials and materials formed as a result of anthropogenic activities, within the framework of which an applied model of methods for the reclamation of saline lands has been developed. On the basis of an applied model transforming the activity of saline lands, a method for developing saline lands has been developed, including the preparation of temporary irrigation and drainage networks and checks, deep ameliorative loosening of the soil across the drains with alternating loosened strips with the same width with the subsequent supply of flushing water to the checks. The method differs in that the development of saline lands is carried out in two symmetrical and parallel-sequential actions in time in annual intervals, with desalinization of saline soils to a certain permissible level with the supply of a leaching rate, taking into account the environmental requirements of environmental management and classification of saline soils and salt tolerance of agricultural crops from very highly saline to highly saline, from highly saline to medium saline, from medium saline to slightly saline and from slightly saline to non-saline, with subsequent cultivation of the corresponding salt tolerant crops: very resistant – resistant – medium resistant – medium sensitive – sensitive.

High Resistivity Reservoirs (Causes And Effects): Sahara Field, Murzuq Basin, Libya

High and low resistivity values is an alarming phenomenon that is usually associated with a very complicated reservoir history and worth looking into. Ordovician sandstone reservoirs are the primary oil producers in the Murzuq basin oil fields that is characterized with an average porosity of 14%, permeability range 410-10,760 md and clean quartz aranite composition. More than fifty wells were drilled in Sahara oil field, but only four of them were announced to have high resistivity values more than 100k ohm-m and ten others to be considered as low resistivity wells (below 50 ohm-m). Therefore, average deep resistivity was mapped in both water and oil legs using all available data set, and the top reservoir was employed as a trend map. They showed distinctive trends for low resistivity readings in oil-leg and confirmed the extreme deep resistivity nature for the wells (W7, W8, W9, and W10). Height above oil water contact and capillary pressure was also calculated for all the wells and revealed a high pressure (400 psi) at the location of the high resistivity wells. As a result, of higher capillary pressure in thicker reservoir area oil might have been able to displace water through geological time by benefitting of more considerable height above oil-water contact, higher connate pressure, and buoyancy forces support, which resulted in occupying all the larger pores and pushed the water into minor scattered pores leading to gradual alteration of reservoir wettability from water to oil-wet. Hence, the brine fluids will no longer be connected to each other inside the pore system. Therefore, they will lose their contribution to resistivity readings, and the resistivity tool will encounter a more resistant medium, which in turn will lead to underestimation of water saturation.

Horizontal projectile motion: comparing free fall and drag resistance

The motion of a particle that is projected into a resistant medium and subjected to a uniform gravitational field is considered. The drag force that acts upon the particle within the medium is proportional to the particle’s speed, the density of the medium, and the cross-section area of the projectile. We review the problem of a horizontal motion with a drag force that is linear in speed. The problem is formulated in terms of particle speed, mass, height, time, and expelled gas velocity. The equations of motion are solved analytically, and a case study is discussed. As a result, we obtain the deviation of the projectile as a function of time because of the expelled gases with or without drag force.

Novel Fractional Models Compatible with Real World Problems

In this paper, some real world modeling problems: vertical motion of a falling body problem in a resistant medium, and the Malthusian growth equation, are considered by the newly defined Liouville–Caputo fractional conformable derivative and the modified form of this new definition. We utilize the σ auxiliary parameter for preserving the dimension of physical quantities for newly defined fractional conformable vertical motion of a falling body problem in a resistant medium. The analytical solutions are obtained by iterating this new fractional integral and results are illustrated under different orders by comparison with the Liouville–Caputo fractional operator.

Comparative Performance of Modified Solid and Composite Wood Samples in Standard Tests

The properties of several modified wood products were evaluated using North American standards to provide comparative data for architects seeking to use these materials. In general, modified wood products had lower moisture uptakes and less shrinkage than unmodified products. Acetylated materials were highly resistant to fungal decay, whereas thermally modified and furfurylated materials were classified as decay resistant. All materials were susceptible to mold, although the nonacetylated moisture-resistant medium-density fiberboard was most susceptible. Thermally modified and furfurylated materials were similar in mold susceptibility to untreated radiata pine sapwood, whereas acetylated materials appeared to be more mold resistant.