A modified discrete scheme in the Ausas cavitation algorithm

In order to reduce the dependence of accuracy on the number of grids in the Ausas cavitation algorithm, a modified Ausas algorithm was presented. By modifying the mass-conservative Reynolds equation with the concept of linear complementarity problems (LCPs), the coupling of film thickness h and density ratio θ disappeared. The modified equation achieved a new discrete scheme that ensured a complete second-order-accurate central difference scheme for the full film region, avoiding a hybrid-order-accurate discrete scheme. A journal bearing case was studied to show the degree of accuracy improvement and the calculation time compared to a standard LCP solver. The results showed that the modified Ausas algorithm made the asymptotic and convergent behavior with the increase of nodes disappear and allowed for the use of coarse meshes to obtain sufficient accuracy. The calculation time of the modified Ausas algorithm is shorter than the LCP solver (Lemke's pivoting algorithm) for middle and large scale problems.

Estimation of C* Integral for Mismatched Welded Compact Tension Specimen

The C* integral for the compact tension (CT) specimen is calculated using the estimation equation in ASTM E1457-15. This equation was developed based on the assumption of material homogeneity and is not applicable to a welded CT specimen. In this paper, a modified equation for estimating the C* integral for a welded compact tension (CT) specimen under creep conditions is proposed. The proposed equation is defined on the basis of systematically conducted extensive finite element (FE) analyses using the ABAQUS program. A crack in the welded CT specimen is located in the center of the heat-affected zone (HAZ), because the most severe type IV cracks are located in the HAZ. The results obtained by the analysis show that the equation for estimating the C* integral in ASTM E1457-15 can underestimate the value of the C* integral for creep-soft HAZ and overestimate for creep-hard HAZ. Therefore, the proposed modified equation is suitable for describing the creep crack growth (CCG) of welded specimens.

Thermal Correction to the Kinnersley Black Hole in a Lorentz-Violating Dirac Field Theory

According to Lorentz-violating theory, the dynamical equation of Dirac particles in the Kinnersley black hole with variably accelerated linear motion is modified. The Hawking quantum tunneling radiation characteristics of Kinnersley black hole are obtained by solving the modified equation. The expression of the Hawking temperature of Kinnersley black hole has been updated.

Optimization of the Plastic Area of a Borehole Based on the Gas Extraction Effect and Its Engineering Application

Gas extraction is most commonly used to control gas disasters in coal mines. The distribution of the plastic zone around a borehole and the sealing quality are key factors affecting gas extraction. In this paper, the plastic zone was simulated by COMSOL, and a theoretical equation of the plastic zone radius was derived. In addition, an antispray hole equipment and the “two plugging and one injection” sealing technology were proposed. The results show that a larger borehole pore size corresponds to a larger plastic zone and larger range of pressure relief of the borehole. The error between the calculated and simulated plastic zone radii is within 1%, and the modified equation is applicable to Puxi mine. The loss and harm caused by borehole spraying are reduced by applying antispray hole equipment. By applying the “two plugging and one injection” sealing technology and phosphogypsum-based self-produced gas expansion paste material to block the borehole, the sealing quality is improved and an accurate gas mixing flow, pure flow, and concentration were obtained. As the plastic zone enlarges, the gas extraction flow gradually increases with, but the relative variation of flow first increases and subsequently decreases. Considering the safety and economy of construction, the optimal radius of the plastic zone is 64.9 mm.

A Modified General Diode Equation

The general diode equation or the non-ideal diode equation is the foundation of circuit models of active devices for the past several decades. Apart from the effect of p-n junction, this equation also accounts for the series bulk resistance of a diode. Despite a reasonable agreement of the equation with measured IV characteristics, it is shown here that the equation is incompatible with basic theories of circuits and systems. Therefore, a modification in the equation is proposed to remove this incompatibility. This modified equation leads to a compact model of a p-n junction diode that has an excellent agreement with the measured IV characteristics.

Level of usage of income smoothing as a creative accounting tool by Balkan banks

The main objective of this study is to find out if Balkan banks use income smoothing (IS) as a creative accounting practice. The IS level is analyzed to see whether banks are focused on these practices as a tool to produce a better picture of financial views in the sight of decision makers. The data are provided from the audited financial reports presented on the banks’ web pages. Eckel’s modified equation was used to find out if banks use the technique of IS. As a result, the findings showed that banks use IS, and the factors that influence the use of this practice are analyzed. The factors studied are: age of banks, profitability, and loan provision. Of a total of seven banks in Kosovo, only three use income smoothing. In Albania, of a total of 11 banks, only one uses income smoothing. Surprisingly, the results show that none of the variables measured affect the usage of income smoothing. The study contributes to understanding the practice of IS on the one hand, and on the other hand, to opening the eyes of investors and depositors promoting vigilance when they make decisions about investing their funds in banks.

Breakup of bubbles in Advanced-Flow Reactor at low Reynolds numbers

In order to study the behavior and mechanism of the bubble breakup in Advanced-Flow Reactor (AFR), visualization experimental study was carried out in a single Corning G1 module. The results show that the breakup behavior in AFR has a significant regularity at low Reynolds numbers (Re<1000), which is closely related to the capillary number Ca and the virtual length l0 of bubbles, and the criterions is also obtained. Most of bubbles in arc-shaped junction divergence of AFR are breakup with permanent obstruction (POB), which could be divided into two stages: squeezing stage and rapid pinch-off stage. The modified equation obtained in this paper can roughly describe the change of the bubble neck at the squeezing stage of POB. The research results provide a theoretical basis for industrial application of AFR and the development of next-generation reactors.