Structural and energy properties of interstitial molecular hydrogen in single-crystal silicon

The structural and energy characteristics of interstitial molecular hydrogen in single-crystal silicon are theoretically studied. The dependence of the potential energy of the system on the position and orientation of the interstitial defect is investigated, and the mechanism of interaction of a hydrogen molecule with a silicon crystal is considered. A three-dimensional model is employed to calculate the energy spectrum of H2 in Si, and the obtained dispersion law is analyzed

RELATIONSHIP BETWEEN THE DEMOGRAPHIC CHARACTERISTICS AND THE EFFECTIVENESS OF E-BANKING TRAINING COURSES BASED ON KIRKPATRICK MODEL FOR EMPLOYEES OF MASKAN BANK BRANCHES IN TEHRAN, IRAN

This study was carried out aimed to measure the Relationship between demographic characteristics and the effectiveness of e-banking training courses for employees of Maskan Bank Branches in Tehran province. The research method in terms of objective is considered as an applied research and information collection method is descriptive-survey. The statistical population of this research includes all employees of Maskan Bank Branches in Tehran Province who have participated in e-banking courses and have a population of about 1100 people. The statistical population of this study includes all employees of Maskan Bank Branches in Tehran Province who have participated in e-banking training courses and have a population of about 1100 people. 285 people were selected using Morgan table and by simple random sampling method. The tool measurement used was questionnaire based on the Kirkpatrick model in four levels of reaction, learning, behavior and results, which its reliability was calculated using Cronbach's alpha coefficient, 0.89 and it was confirmed. Descriptive and inferential statistical methods (one-way t-test, one-way ANOVA and Pearson correlation coefficient) were used in order to analyze the obtained data. According to the results of t-test, e-banking training courses were effective for employees of Maskan Bank Branches in Tehran province. Also, the analysis of demographic findings based on the results of the one-way between-subjects ANOVA showed that employees' attitudes at different positions, work experience or education level were not significantly different towards the factors affecting the effectiveness of e-banking training courses and none of them should be omitted from e-banking courses

Optimal active particle navigation meets machine learning

The question of how "smart" active agents, like insects, microorganisms, or future colloidal robots need to steer to optimally reach or discover a target, such as an odor source, food, or a cancer cell in a complex environment has recently attracted great interest. Here, we provide an overview of recent developments, regarding such optimal navigation problems, from the micro- to the macroscale, and give a perspective by discussing some of the challenges which are ahead of us. Besides exemplifying an elementary approach to optimal navigation problems, the article focuses on works utilizing machine learning-based methods. Such learning-based approaches can uncover highly efficient navigation strategies even for problems that involve e.g. chaotic, high-dimensional, or unknown environments and are hardly solvable based on conventional analytical or simulation methods.Comment: 7 pages, 3 figure

Joint Sum Rate And Error Probability Optimization: Finite Blocklength Analysis

We study the tradeoff between the sum rate and the error probability in downlink of wireless networks. Using the recent results on the achievable rates of finite-length codewords, the problem is cast as a joint optimization of the network sum rate and the per-user error probability. Moreover, we develop an efficient algorithm based on the divide-and-conquer technique to simultaneously maximize the network sum rate and minimize the maximum users' error probability and to evaluate the effect of the codewords length on the system performance. The results show that, in delay-constrained scenarios, optimizing the per-user error probability plays a key role in achieving high throughput.Comment: Accepted for publication in IEEE Wireless Communications Letter

Investigation of Hollow and Dense Droplet Impact on Solid Surfaces

Droplet impact and its flattening on a surface play an essential role in many industrial applications such as inkjet printing, agriculture, and plasma spraying. Understanding the physics of droplet spreading is the key to maintaining the mass transfer process in all relevant applications. Two different problems are investigated in this study. In the first parts, the behavior of a hollow droplet after impact on a surface is considered, while in the last chapter, the effect of gas desorption on the flattening and solidification of a molten particle in investigated. Most of the droplets observed in nature are dense droplets. Nevertheless, special droplets have been observed in several industrial applications such as aerosol transfer from the sea, oxygen dissolution, controllable biomedicine, and thermal spray coating which are called hollow droplets. In plasma spraying process, the accumulation of these flatten droplets (splats) on top of each other forms a coated layer. Due to their embedded medium, the cavity-containing droplets (hollow droplets) trigger cavitation when they reach the target and influence the splat properties by releasing the inner substance. However, it is difficult to study the impact and flattening of hollow droplets in thermal spraying, regarding the harsh environments, and phenomena small size and high velocity. To better understand the flattening process of a hollow droplet, in this work, a comprehensive experimental, numerical, and theoretical study is performed on water and glycerol droplets impacting on a rigid surface. The experiments are repeated on different surfaces, including aluminum, sand-blasted steel, and superhydrophobic. The results show that the mechanisms of the post-impact process of hollow droplets are different from those of dense droplets in several aspects. We study the role of surface wettability, liquid properties, impact velocity, surface angle, and bubble size and location on the droplet flattening process. In the numerical part, compressible Navier-Stokes equations are solved using the volume of fluid (VOF) method. A theoretical model is developed to analyze the maximum spreading diameter of the hollow droplet impact analytically. Its prediction is in good agreement with the experimental and numerical results. The comparison of simulation results with the experimental photographs shows that the numerical solver can correctly predict the hollow droplet shape evolution. It is demonstrated that flattening a hollow droplet has two significant distinctions compared to a dense droplet flattening. The first distinction is the formation of a counter-jet following the collision of a hollow droplet impact perpendicular to the surface. It is proven that the formation of the counter-jet is an inherent phenomenon of hollow droplet flattening and is unaffected by impact velocity or substrate angle. Nevertheless, it is revealed that the counter-jet length depends on droplet velocity or liquid viscosity. The second distinction is the ultimate shape of the flattened droplet. After contact on a hydrophobic surface, the dense droplet partially recoils toward the center and produces a dome shape. However, upon impact on a hydrophobic surface, the hollow droplet takes the form of a donut. This is owing to the perturbations caused by bubble rupture on the spreading droplet surface. As a result of these perturbations, the spreading liquid sheet is fragmented and, the droplet is unable to recoil toward the center, forming a donut shape. The results show that the spreading diameter and the counter-jet height formed after the hollow droplet impact grows with impact velocity increasing. Investigating the size and location of the entrapped bubble shows an optimum bubble size that facilitates the hollow droplet flattening. It is also demonstrated that the ripples on splats produced by the hollow droplets with a larger bubble size are higher than those of small bubbles. In the end, the effects of surface gas desorption on the splat formation are studied. In plasma spray, the splats resulting from the impact, spreading, and solidification of molten particles are the building blocks of the spray coatings. Fragmented splats are formed on substrates held at room temperature and atmospheric pressure. Although the formation of a fragmented splat is attributed to adsorbates on the substrate surface, its dynamics have not been adequately addressed. In this study, a numerical model is developed to investigate the formation of fragmented splats during droplet flattening and solidification in plasma spraying conditions. Compressible Navier—Stokes equations are solved, and the volume of fluid (VOF) method is used to capture the liquid and gas interface. In addition, the source term method is used to capture the solidification process during droplet flattening. Moreover, a new boundary condition is defined to consider the effect of gas desorption on the substrate surface after droplet impact. The numerical results show that gas desorption from the surface produces a barrier layer between the droplet and the substrate. This high-pressure region detaches the edge of the spreading droplet from the surface and forms a liquid sheet. The liquid sheet rises above the substrate and spreads up to 2 times more than droplets impacting surfaces without gas desorption. The fragmentation of the liquid film follows the overspreading of the droplet. As a result, only a portion of the initial droplet remains at the location of the impact, which forms a small solidified splat

Critical review of “the epistemology of involvement” in understanding religious beliefs

John Cottingham, a contemporary English philosopher, considers the best way to understand religious beliefs to be an empathic understanding. He calls his theory “the epistemology of involvement”. Based on this theory, in order to understand religious beliefs, one should put aside the detachment approach and by entering the life of faith, provide the conditions for the realization of the religious experiences of the believers, and at the same time, maintain the critical opinion in this sympathetic participation in religion. He considers such an approach to be a middle way between Kierkegaard's irrationalism and Plantinga's relativism and considers it generalizable to other philosophical fields. This approach faces criticism. First, before entering a religious life, it is necessary to evaluate its worldview, and this evaluation precedes the practical system and literary and emotional texts of that religion. Second, there is no connection between an empathetic understanding of religion and entering into a life of faith, and thirdly, by entering into a life of faith, the acceptance of a belief will be involuntary, and after the realization of such a belief, it is not possible to criticize it

Neurodevelopmental Outcomes of Infants with Benign Enlargement of the Subarachnoid Space

  ObjectiveBenign enlargement of the subarachnoid space (BESS) is the most common cause of macrocephaly in infants. This study aimed to evaluate the neurodevelopmental outcomes in infants with BESS. Materials & Methods In this follow-up study, all records of infants diagnosed with BESS in 2012-2016 were assessed. A clinical follow-up examination was carried out at 6, 12, 18, and 24 months of age to assess the macrocephaly outcomes. Denver Developmental Screening Test-II (DDST-II) was used for evaluating the psychomotor development of infants at 24 months of age. All data were entered in SPSS Version 13, and descriptive statistics were measured. Results Out of 32 infants included in this study, 28 (87.5%) were boys. Five cases of prematurity history (15.6%), and 23 cases of macrocephaly in the family (71.9%) were recorded. The mean age of BESS diagnosis was 6.8 months (SD=3.2). subdural hematoma was reported in one infant (3.1%). Also, 28 infants showed macrocephaly at 18 months of age (83.3%). Seven patients had developmental delay, according to DDST-II (22%). The mean head circumference at birth and six months of age was significantly greater in infants with developmental delay compared to those with normal development. There was a significant difference between the mean head circumference at birth (P=0.05) and the mean head circumference at six months of age (P=0.02). Conclusion Developmental delay is frequent in BESS infants, especially those with macrocephaly at birth and six months of age, and requires medical attentio