Probable Position Research Articles

Electronic structure and field emission characteristics of a new kind of BeO nanotubes: A first-principles study

First-principles calculations are used to investigate electronic and field emission characteristics of (5, 5) capped BeO nanotubes (BeONTs), which indicate that their emission currents under external electric fields are close to those of carbon nanotubes, and decagons on their apexes are the most probable positions for electron emission. In addition, work functions of the (5, 5) BeONTs decrease linearly with applied electric fields. The remarkable influence of lithium adsorption on their field emission characteristics is also investigated. Their work functions decline distinctly after lithium adsorption, while the emission currents have been improved by more than one order of magnitude. Moreover, there is a polynomial relationship between the total currents and the external fields.

A One-Way Coupled Hydrodynamic Advection-Diffusion Model to Simulate Congested Large Wood Transport

An advection-diffusion model is proposed to simulate large wood transport during high flows. The mathematical model is derived from the wood mass balance, taking into consideration both the wood mass concentration and the log orientation, which affects log transport and, most importantly, wood accumulation. Focusing on wood mass transport, the advection-diffusion equation is implemented in a hydrodynamic model to provide a one-way coupled solution of the flow and of the floating wood mass. The model is tested on a large series of flume experiments, involving at least 30 logs and different control parameters (flow Froude number, log length, diameter, release point). The validation through the experimental data shows that the proposed model can predict the correct displacement of the most probable position of the logs and to simulate with a sufficient accuracy the planar diffusion of the wooden mass. Transversal wood distribution is more accurate than the streamwise one, indicating that a higher control on the longitudinal diffusion needs to be implemented.

Neutron total scattering investigation on the dissolution mechanism of trehalose in NaOH/urea aqueous solution.

Trehalose is chosen as a model molecule to investigate the dissolution mechanism of cellulose in NaOH/urea aqueous solution. The combination of neutron total scattering and empirical potential structure refinement yields the most probable all-atom positions in the complex fluid and reveals the cooperative dynamic effects of NaOH, urea, and water molecules in the dissolution process. NaOH directly interacts with glucose rings by breaking the inter- and intra-molecular hydrogen bonding. Na+, thus, accumulates around electronegative oxygen atoms in the hydration shell of trehalose. Its local concentration is thereby 2–9 times higher than that in the bulk fluid. Urea molecules are too large to interpenetrate into trehalose and too complex to form hydrogen bonds with trehalose. They can only participate in the formation of the hydration shell around trehalose via Na+ bridging. As the main component in the complex fluid, water molecules have a disturbed tetrahedral structure in the presence of NaOH and urea. The structure of the mixed solvent does not change when it is cooled to −12 °C. This indicates that the dissolution may be a dynamic process, i.e., a competition between hydration shell formation and inter-molecule hydrogen bonding determines its dissolution. We, therefore, predict that alkali with smaller ions, such as LiOH, has better solubility for cellulose.

Corrosion inhibition effect of 2-N-phenylamino-5-(3-phenyl-3-oxo-1-propyl)-1,3,4-oxadiazole on mild steel in 1 M hydrochloric acid medium: Insight from gravimetric and DFT investigations

Mild steel corrosion caused by exposure to the hydrochloric acid solution is a major problem affecting a wide range of industries. Iraq is an oil-producing country, and erosion is responsible for a significant amount of total operating expenses and is a potential natural hazard associated with oil production as well as its transportation operations. The novelty of this work is to study the protective response of the synthesized 2-N-phenylamino-5-(3-phenyl-3-oxo-1-propyl)-1,3,4-oxadiazole (NPOPO) which was analysed analytically on the corrosion of mild steel in 1.0 M hydrochloric acid using gravimetric and thermometric techniques. To compare the examined NPOPO electronic structure parameters with the inhibitive performance (IE%) value, the quantum chemical calculations were investigated. Quantum chemical parameters such as Frontier Molecular Orbitals (HOMO and LUMO), the energy gap (ΔE = ELUMO-EHOMO), electronegativity, chemical softness, hardness, and the number of electron transfers (ΔN) were determined and explained. The sites having nitrogen atoms are the most probable positions for coordination covalently with the iron atoms on the surface of mild steel (MS) by donating electrons to unoccupied d-orbitals of Fe atoms. The tested inhibitor obeyed the Langmuir adsorption isotherm model. Thermodynamic parameters such as activation energy (Ea), enthalpy of activation (ΔH∗), the entropy of activation (ΔS∗), and energy of adsorption (ΔGadso) at temperatures 303, 313, 323, and 333 K were evaluated and discussed. The DFT findings as agreeable with experimental outcomes revealed that the investigated NPOPO is an efficient inhibitor for mild steel corrosion in HCl medium.

Электронная структура и диффузия натрия в Na-=SUB=-4-x-=/SUB=-K-=SUB=-x-=/SUB=-Mg(MoO_4)-=SUB=-3-=/SUB=-

The electronic structure and sodium diffusion in Na4-xKxMg(MoO4)3 with an alluadite structure have been investigated by ab initio methods. It was found that this molybdate is an insulator with a band gap of 3.5 eV for x = 0.25. The most probable positions of potassium in the sodium sublattice have been determined, and the preferred pathways for sodium migration have been established. It has been shown that the barriers to sodium diffusion in Na4-xKxMg(MoO4)3 significantly depend on the composition, position of potassium, and migration path. The introduction of potassium leads to a significant decrease in the barriers to both one-dimensional (1D) and two-dimensional (2D) sodium diffusion. However, the presence of potassium in 1D channels can hinder the rapid migration of sodium, and a sharp increase in conductivity occurs only at high temperatures due to the order-disorder transition.

A Method of Theodolite Installation at the Intersection of Two perpendicular lines (Dept.C)

The problem of theodolite installation at the intersection of two perpendicular lines is very important to set walls and columns in any structural building. In this paper there is a simple solution for laying out a point corresponding to the crossing of principle building axes. Besides to, the accuracy evaluation of this point is available. This is by carrying out two examples for evaluating the most probable position of this point by theodolite 2T30 and T5.

Manifestations of Key-Word Terms in ELT Research Publications: Are We Not Tuned to Genuine, Art-based Qualitative Lines of Inquiry Yet?

Stated key words after the abstract section in research articles are among those lines of inquiry which have received less attention in Applied Linguists (AL) studies. In this paper, the researcher explored the distribution of stated key terms and expressions as used by 73 researchers in AL domains in both local (NOORMAGZ) and global database publishers (SAGE, ELEVIRE, SINCENCE DIRECT) Those Scimago journal lists, which were abstracted in Thomson Reuters Web of Science [WoS] journals were precisely screened in terms of their compatibility with title vs. topic match index as well as their position in the research articles throughout the whole sampled research papers including Introduction, Review of Literature, Method, Results & Discussion (IRMRD) to explore authors’ tendencies towards art-based utilization of key word selection/assignment for research writing aims. The results over title-topic match indicated that at least one or two stated key words significantly appeared in the title of research paper within both local and global databases with the higher preference for keyword-title match among Iranian researchers. Regarding the most probable positions in the sampled research articles, gained data in this research could not significantly show any differences between local and global researchers. Possible implications were discussed in the light of critical, art-based approaches for key word elaboration/explanation in English Language Teaching (ELT) and AL research.

Структура молекулы изомера 17894 (С1) фуллерена C76: причины её нестабильности и вероятные пути стабилизации

It is well-known that non-IPR fullerenes are highly unstable. For this reason, they cannot be obtained as pristine fullerenes; however, some of them become stable as derivatives (exohedral or endohedral). In this article, we attempted to elucidate in detail molecular structure for such a non-IPR fullerene. Using theoretical approach supported by DFT calculations, the features of molecular structure of isomer 17894 (C1) of fullerene C76 with data about distribution of single, double and delocalized π-bonds as well its structural formula has been determined for the first time. The instability of the studied fullerene molecule caused by its open-shell structure and significant local overstrains related to the high folding angle value of pentagons in pentalene fragment. The supposed synthesis of the endohedral molecule starts with the ionic pair formation, i.e. anionic fragment of fullerene cage and metal cation electrostatically bound with it. It would lead to closing of open electron shell of fullerene and local overstrain release at pentalene fragment. As to the exohedral derivatives the probable positions of addends are discussed. Both methods in their own demonstrate the possibilities to stabilize the molecule of the C76 isomer 17894. The elucidation and analysis of structural features along with electronic characteristics of non-IPR fullerene molecules appear to be useful for predicting the possibility of their synthesis as derivatives and will assist in determination of their reactivity. This will ensure the targeted production of fullerenes and their derivatives for the needs of medicine, electronics and other industries. The fundamental knowledge of the properties of nanoobjects, namely fullerenes, is actually developing as the independent direction with a long-term perspective.

Investigation on the interaction of brazilin with bovine serum albumin using multi-spectroscopic and computational methods: Exploring the binding mechanism and inhibitory effect on amyloid aggregation

Free and active concentration of drug in the blood plays a vital role in the disease treatment. Binding of drug to serum albumin, an important transport protein in plasma, usually improves its aqueous solubility, stability and bioactivity. Brazilin (Bra) is a natural compound extracted from Caesalpinia sappan with numerous pharmacological applications, while the behavior of Bra in circulatory system is still unknown. Therefore, in the present work, we firstly examined the interaction of Bra with bovine serum albumin (BSA) using various spectroscopic and computer simulation techniques. The static quenching mechanism and moderate binding affinity (2.18 × 104 M−1 at 298 K) were obtained through fluorescence spectroscopic measurement. Thermodynamic analysis results indicated that hydrophobic interactions and hydrogen bonds played a major role in the binding process. Site marker competitive experiments and molecular simulation suggested that the probable Bra-binding position was located in subdomain IIA of BSA. UV–vis absorption, circular dichroism (CD) and dynamic light scattering (DLS) experiments suggested the conformational changes of BSA induced by Bra. Additionally, the potential of Bra to inhibit the formation of amyloid fibrils, in vitro, has also been analyzed. Thioflavin T (ThT) binding, 8-anilino-1-naphthalenesulfonic acid (ANS) binding, Congo red binding, DLS, CD, fluorescence microscopic image, atomic force microscopy (AFM), size-exclusion chromatography (SEC) and native gel-electrophoresis methods were used, and all confirmed the anti-amyloidogenic behavior of Bra. In short, our findings have provided some important insights into the binding mechanism of Bra with BSA, and would be helpful in designing suitable agents against amyloid diseases.

Geo Electric Study in Hydrogeology According to the Axis Hassi Naga – Hassi Khebi of Tindouf (Southwestern Algeria)

Abstract The hydrogeological environment of the Saharan North East region of Tindouf is of utmost interest, particularly in agriculture. In fact, exploitation and exploration processes must be analysed to ensure sufficient water production. This study demonstrates the value of spatial processing and exploitation of geoelectric and geological data in the study area and facilitates interpretation. The results of the electrical survey and the spatial analysis of the data allowed us to design a complete model that met the needs of hydrogeology. The applied methodology consists in breaking down our subject into three (3) classes of entities: geomatics, geophysics and hydrogeology. Synthetic mapping based on continuity is the result of studying two sites (Hassi Naga and Hassi Khebi) for geological analysis. Knowing that the electrical resistivity is between 0 and 3000 Ohm-meter, we were able to construct thematic maps showing the spatial distribution of the facies and the probable positions of the boreholes. The study provided with a geo-spatial model highlighting the impact of measurements in hydrogeology of the area considered that was called SIHE (Information System for Environmental Hydrogeology).

Germany-Iran Relations in Political-Military Sphere: The Impossible Unlocking of Potential?

The article explores the current relations between Germany and Iran in politicalmilitary sphere. Both countries belong to the category of emerging powers (the Germany is perhaps the single emerging power among Euro-Atlantic states). Outlining the contours of bilateral relations, the authors underline the presence of imperial historical code in each country, the growing internal political problems (dwindling authority of the ruling elites) and mutual interest in deepening trade-industrial partnership with Germany becoming a technological modernizer of Iranian economy.The authors show that Iranian factor has a growing impact over German policy in the Near East and the Middle East, especially in Lebanese, Syrian, Iraqi and Yemeni armed conflicts. In the first three cases Germany tries to limit the scale, the character (non-combatant capabilities), geographic area (not in deep regions) of the Bundeswehr usage. One of the key reasons of it is that Germany avoids being drawn into action against the Iranian troops or its junior allies («Hezbollah» in Lebanon, Shia combatants in Southern Iraq). Germany also recognizes that ignoring Iranian interests in each of these cases will make it difficult to maintain its political-military presence in the region. Because of the Yemen conflict with active participation of Saudi Arabia Germany has imposed arms embargo for the Kingdom.Germany attempted to keep the Iranian nuclear deal after Trump`s administration withdrawal from the agreement. The authors try to estimate the probable position of Germany towards possible military-political crisis in the region involving Iran and especially towards a potential US war against Iran.What result will Germany strive for in the Iranian direction? According to the authors, this is a significantly expanded formula of 2015. In addition to maintaining the JCPOA and mutually beneficial growth in trade and economic cooperation, this formula includes:– minimizing the threat of a military conflict against Iran (which has become especially important after the assassination of General Qasem Soleimani on January 3, 2020);– in exchange for this clear limitation of Iran’s influence in Lebanon, Syria, Iraq and Yemen.

Analysis of the finiteness for the first collision time between two randomly moving particles

The finiteness of the collision time between two different randomly moving particles is presented by providing more useful analysis that gives stronger and finite moment. The triangular arrays and the uniform integrability conditions of the all probable positions non-stationary random sequence are used. In addition, an important property of Marcinkiewicz laws of large numbers and Hoffman-Jorgensen inequality are presented in this analysis. All of them are deriving to provide the sufficient conditions that give more stronger moments of the first meeting time in the probability space.

Evaluation of the accuracy of the ship location determined by GPS global positioning system on a given sea area

The current location of navigation and navigation depends heavily on global satellite navigation systems, mainly GPS (Global Position System). In actual maritime practice, the position of the ship is determined to be the most probable position and will be the center of the circle of probability containing the ship’s position. However, this is not entirely accurate because the exact position on the chart depends on many factors such as deviation of the geodetic system, the accuracy of the chart, etc. On the other hand, the probability circle contains the location. The ship is scalar, the radius of error of the probability circle depends on many factors, etc. Therefore, determining the probability location with the highest accuracy is a rather complex problem. In particular, in the waters where the safety system is not complete, the level of survey is not good: Solomon Islands, Papua New Guinea, Indonesia, Cambodia, Vietnam, etc. actual errors of GPS location operating above. The chart is much larger than the error recommended by the manufacturer. In the context of the article, the author proposes a method for determining the probability area containing the actual ship position and its orientation to improve high safety in manoeuvring and navigating vessels at sea, testing on coastal Vung Tau - Vietnam.

The finiteness of the first meeting time between a Gaussian jump and a Brownian particles in the fluid

In this paper, we present more analysis about the finiteness of the first meeting time between Gaussian jump and Brownian particles in the fluid. Rather than using the uniform integrability conditions which are detailed in El-Hadidy [Mod. Phys. Lett. B 33(22) (2019) 1950256], we show the triangular arrays of the random sequence that represents the probable positions of the first meeting at any time [Formula: see text], to get the stronger moment conditions which are sufficient for the finiteness of this time.

Improved Fast Method of Initial Rotor Position Estimation for Interior Permanent Magnet Synchronous Motor by Symmetric Pulse Voltage Injection

The precise information of initial rotor position is very important to high performance Interior Permanent Magnet Synchronous Machine (IPMSM) adopting incremental encoder, which can normally be obtained by the high-frequency (HF) rotating or pulsating voltage injection methods. However, the demodulation procedure may confront with the challenge of constrained stability and limited accuracy. For improving estimation accuracy, an improved impulse injection method with merits of simple and fast is proposed. It is carried out by generating a series of phase-axial injections to calculate the probable rotor position, then injecting two reciprocal voltage pulses to obtain the rotor polarity, and finally injecting iterative voltage vectors to obtain the real position rapidly. During the estimation process, the filters to extract the high frequency current signals are not needed. The method effectiveness is validated by the measured results of IPMSM test platform. In the same time, its application limitation is deduced by comparison with the measured results between IPMSM and surface-mounted PMSM (SPMSM). It is shown that the estimation algorithm is compatible with motor parameter differences and can reduce the influence of inductance saturation and nonlinear voltage error. Therefore, the proposed method not only improves the accuracy and robustness of the PMSM sensorless startup control, but also ensures the fast response.

Camera and Radar Sensor Fusion for Robust Vehicle Localization via Vehicle Part Localization

Many production vehicles are now equipped with both cameras and radar in order to provide various driver-assistance systems (DAS) with position information of surrounding objects. These sensors, however, cannot provide position information accurate enough to realize highly automated driving functions and other advanced driver-assistance systems (ADAS). Sensor fusion methods were proposed to overcome these limitations, but they tend to show limited detection performance gain in terms of accuracy and robustness. In this study, we propose a camera-radar sensor fusion framework for robust vehicle localization based on vehicle part (rear corner) detection and localization. The main idea of the proposed method is to reinforce the azimuth angle accuracy of the radar information by detecting and localizing the rear corner part of the target vehicle from an image. This part-based fusion approach enables accurate vehicle localization as well as robust performance with respect to occlusions. For efficient part detection, several candidate points are generated around the initial radar point. Then, a widely adopted deep learning approach is used to detect and localize the left and right corners of target vehicles. The corner detection network outputs their reliability score based on the localization uncertainty of the center point in corner parts. Using these position reliability scores along with a particle filter, the most probable rear corner positions are estimated. Estimated positions (pixel coordinate) are translated into angular data, and the surrounding vehicle is localized with respect to the ego-vehicle by combining the angular data of the rear corner and the radar's range data in the lateral and longitudinal direction. The experimental test results show that the proposed method provides significantly better localization performance in the lateral direction, with greatly reduced maximum errors (radar: 3.02m, proposed method: 0.66m) and root mean squared errors (radar: 0.57m, proposed method: 0.18m).

Detection of point scatterers using diffraction imaging and deep learning

ABSTRACTDiffracted waves carry high‐resolution information that can help interpreting fine structural details at a scale smaller than the seismic wavelength. However, the diffraction energy tends to be weak compared to the reflected energy and is also sensitive to inaccuracies in the migration velocity, making the identification of its signal challenging. In this work, we present an innovative workflow to automatically detect scattering points in the migration dip angle domain using deep learning. By taking advantage of the different kinematic properties of reflected and diffracted waves, we separate the two types of signals by migrating the seismic amplitudes to dip angle gathers using prestack depth imaging in the local angle domain. Convolutional neural networks are a class of deep learning algorithms able to learn to extract spatial information about the data in order to identify its characteristics. They have now become the method of choice to solve supervised pattern recognition problems. In this work, we use wave equation modelling to create a large and diversified dataset of synthetic examples to train a network into identifying the probable position of scattering objects in the subsurface. After giving an intuitive introduction to diffraction imaging and deep learning and discussing some of the pitfalls of the methods, we evaluate the trained network on field data and demonstrate the validity and good generalization performance of our algorithm. We successfully identify with a high‐accuracy and high‐resolution diffraction points, including those which have a low signal to noise and reflection ratio. We also show how our method allows us to quickly scan through high dimensional data consisting of several versions of a dataset migrated with a range of velocities to overcome the strong effect of incorrect migration velocity on the diffraction signal.

The EUSTACE global land station daily air temperature dataset

AbstractWe describe a global dataset of quality‐controlled in situ daily air temperature observations covering the period 1850–2015, developed in the framework of the EUSTACE (EU Surface Temperature for All Corners of Earth) project (www.eustaceproject.org). The dataset includes a total of 35,364 daily series of maximum and minimum temperature obtained from seven different collections. About 97% of the series are publicly available in a common format, while the remaining 3% can be obtained from the original data providers. Unlike other similar products, duplicates have been removed without blending of series, which simplifies data traceability and improves the temporal homogeneity of the individual series at the cost of a smaller average length. Residual artificial signals (breakpoints) in the series caused by station relocations, changes in instrumentation, etc., have been detected by means of the combination of four breakpoint detection tests, four variables and three temporal aggregations. The combined results give not only the most probable position of the breakpoints, but also a measure of their likelihood. The reliability of the detection was estimated for each year of each target series, based on the number of reference series and on their correlation with the target series. Moreover, its general performance was evaluated through a benchmark of synthetic series. This product will be combined with datasets of marine and ice in situ air temperature observations and with measurements from satellite to produce the first complete global statistical reconstruction of daily near‐surface air temperature.

The Geometry of Elliptical Probability Contours for a Fix using Multiple Lines of Position

Navigation methods, traditional and modern, use lines of position in the plane. Standard Gaussian assumptions about errors leads to a constant sum of squared distances from the lines defining a probability contour. It is well known these contours are a family of ellipses centred on the most probable position and they can be computed using algebraic methods. In this paper we show how the most probable position, the axes and foci of ellipses can be found using geometric methods. This results in a ruler and compasses construction of these points and this gives insight into the way the shape and orientation of the probability contours depend on the angles between the lines of position. We start with the classical case of three lines of position with equal variances, we show how this can be extended to the case where the variances in the errors in the lines of position differ, and we go on to consider the case of four lines of position using a methodology that generalises to an arbitrary number of lines.

Experimental and theoretical investigations of Mn-N-co-doped TiO2 photocatalyst for visible light induced degradation of organic pollutants

The present paper reports the experimental and theoretical investigations of Mn-N-co-doped TiO2 photocatalyst for degradation of organic pollutants. Mn-N-co-doped TiO2 photocatalyst was synthesized by using cavitation induced technique and the incorporation of dopant (Mn2+) ion in the lattice of N-doped TiO2 and was confirmed from X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive X-ray spectrometry (EDS), Fourier transform infrared (FTIR), Raman, UV–vis and Electron paramagnetic resonance (EPR) spectroscopy. The effect of Mn2+ ion on variation in structural, morphological and optical properties of catalyst was assessed. The photocatalytic response of the Mn-N-co-doped TiO2 catalyst was investigated at different wavelength regions (490 nm, 565 nm, and 660 nm) of the solar spectrum for the degradation of organophosphate pesticides quinalphos and 2- chlorophenol. The present study has highlighted the photocatalytic efficiency of the Mn-N-co-doped TiO2 photocatalyst. To understand the photocatalytic activity at the molecular level, the adsorption energies (ΔEad) of quinalphos and 2-chlorophenol with the N-doped TiO2 and Mn-N-co-doped TiO2 photoctalysts were calculated with density functional theory (DFT) using B3LYP (Becke’s 3-parameter exchange functional with Lee-Yang-Parr correlation energy) functional and 6-311 G(d,p)/LANL2DZ basis set. The obtained ΔEad values indicated the probable positions on the surface of photocatalysts where pesticide molecules could adsorb and degrade efficiently. The computational study can be used for comprehensing the mechanism of degradation of pollutant molecules in the presence of photocatalysts.