Field Analysis Method Research Articles

Bilt-in turbulence modelling solution method

THE PURPOSE. The aim of the work is to find a method for mathematical modeling and analysis of inhomogeneous physical fields and the influence of internal structures on these fields. Solutions are sought in areas in which there are subdomains with already known behavior (“embedded” areas and embedded solutions). The goal is to find a modeling method that does not require a change in existing software and is associated only with the modification of the right-hand sides of the equations under consideration. METHODS. The proposed method of mathematical modeling is characterized by the use of characteristic functions for specifying the geometric location and shape of embedded areas, for specifying systems of embedded areas (for example, spherical fillings or turbulent vortices) without specifying them as geometric objects, for modifying the calculated differential equation within the embedded areas. RESULTS. A theorem is formulated and proved (in the form of a statement) that formalizes the essence of the proposed method and gives an algorithm for its application. This algorithm consists in a) representation of the differential equation of the problem in another analytical form; in this form, a term is added to the original differential equation (to its right-hand side), in the presence of which this equation gives a predetermined ("built-in") solution in the necessary regions and b) a representation of the desired solution (using the characteristic function) in the form in which this solution takes the form of either the desired function (in the main area) or the specified functions (in the embedded areas). Examples of calculations from two physical and technical areas - thermal conductivity and hydrodynamics are presented. The result of the work is also the calculation of a turbulent flow in a pipe, in which a system of ball vortices, the speed and direction of rotation of these vortices are specified. CONCLUSION. The proposed method makes it possible to simulate complex physical processes, including turbulence, has been tested, is quite simple and indispensable in cases where embedded structures can be specified only by software.

Mathematical foundation of Capon's method for planetary magnetic field analysis

Abstract. Minimum variance distortionless projection, the so-called Capon method, serves as a powerful and robust data analysis tool when working on various kinds of ill-posed inverse problems. The method has not only successfully been applied to multipoint wave and turbulence studies in the context of space plasma physics, but it is also currently being considered as a technique to perform the multipole expansion of planetary magnetic fields from a limited data set, such as Mercury's magnetic field analysis. The practical application and limits of the Capon method are discussed in a rigorous fashion by formulating its linear algebraic derivation in view of planetary magnetic field studies. Furthermore, the optimization of Capon's method by making use of diagonal loading is considered.

Three-dimensional quantitative structure-activity relationship study on gas chromatographic retention index of the fragrance compounds of Liliumspp

Quantitative structure-activity relationship models on the gas chromatographic retention index of the 38 volatile fragrance compounds of Liliumspp were investigated and established by comparative molecular field analysis (CoMFA) and comparative molecular similarity index (CoMSIA) methods. The robustness and predictive performance of the developed models were assessed using external test set validation and leave-one-out cross validation. Further, the effects of the molecular structure on the gas chromatographic retention indices of these compounds were intuitively studied in light of the three-dimensional contour maps of molecular fields provided by the developed CoMSIA and CoMFA models. The validation results demonstrated that both the models could accurately predict the retention indices of the investigated components. The influence of the molecular structure on the retention indices could be reasonably explained by these models. Moreover, the prediction accuracy of the CoMSIA model was slightly higher than that of the CoMFA model. Obviously, the proposed CoMSIA model is more promising for the analysis of the volatile fragrance compounds of Lilium spp.

Multiple Circular Arrays of Vector Sensors for Real-Time Sound Field Analysis

This article proposes multiple circular arrays of vector sensors for analyzing the three dimensional sound field. By exploiting the fact that a finite number of spatial basis functions can represent the sound field within a region, the designed arrays allow the analysis of the sound field around the arrays sequentially by either a frequency-domain method or a time-domain method. The arrays are compact and thus are suitable for integrating with small-sized devices. The time-domain method is of low latency and computationally simple, and thus are suitable for providing the devices with spatial acoustic features in real-time. The effectiveness of the proposed arrays and the sound field analysis methods are confirmed by simulations, and compared with another array.

3-D Printed Terahertz Lens to Generate Higher Order Bessel Beams Carrying OAM

Conventional vortex beams carrying orbital angular momentum (OAM) suffer from the limitation of beam divergence in wireless communications applications. This article proposes novel 3-dimensional (3-D) printed discrete dielectric lenses (DDLs) for generation of nondiffractive OAM beams operating at 300 GHz. By virtue of its arbitrary aperture phase control capability, a terahertz (THz) DDL combining the functionalities of three conventional bulky refractive hyperbolic, spiral phase plane, and aixcon lenses is proposed to generate nondiffractive Bessel vortex beam carrying OAM. An aperture field analysis method is also developed to evaluate the radiation performance of the DDL antennas. Furthermore, to cover the OAM signal in an intended longitudinal region, two DDL synthesis methods are explored to generate extended higher order Bessel beams carrying OAM. The first approach is based on geometric optics, while the second uses the alternating projection method (APM) to optimize the aperture phase distribution of the DDL. Two THz DDLs are conveniently fabricated by 3-D printing technology. Measured results demonstrate that THz nondiffractive OAM beams can be successfully generated by the designed DDLs. The generated THz OAM beam with attractive nondiffractive characteristic may open new opportunities for next-generation ultra-high-speed wireless communications.

Development Strategy of Agricultural Equipment and Machinery Rental Service Unit (UPJA) in Supporting Rice Farming in Rogojampi Sub-district Banyuwangi Regency

The strategy of developing agricultural equipment and machinery in the framework of utilizing agricultural mechanization innovation and technology is carried out by growing and developing the institutional system of Agricultural Equipment and Machinery Rental Service Unit (UPJA). In Banyuwangi Regency, the UPJA institution that is classified as UPJA is developing towards professionalism is UPJA Tani Makmur Gapoktan Surangganti, Rogojampi Sub-district. The purpose of this study was to determine the development strategy of UPJA Tani Makmur as an effort to increase the role of UPJA in supporting increased productivity and efficiency of rice farming. The determination of the research area is determined based on a purposive method. The research sampling method uses the expert system method. The analytical method used is the Force Field Analysis (FFA) method. The results of the analysis show that based on the Key Success Factors (FKK) of the Driving Forces and Restraining Forces in the FFA analysis, the appropriate. UPJA Tani Makmur development strategy, among others, are: UPJA Management must increase more intensive efforts to socialize the use of alsintan to farmers, by socializing to farmers the benefits and advantages of using Alsintan in rice farming, as well as socializing the UPJA service system provided to farmers using services alsintan of UPJA Tani Makmur, especially to members of the Surangganti Gapoktan. The next effort is to expand marketing around and outside the Rogojampi Sub-district which has a large potential market share.Keywords—Force Field Analysis, Strategiy, UPJA

Study on the influence of venturi on the cleaning performance of elliptical filter cartridge

Pulse-jet cartridge filter is one of the high efficiency dust collectors for capturing ultra-fine powder. The incomplete cleaning becomes a difficult problem in the application of filter cartridge. However, most of the existing studies are focused on the cleaning performance of the circular cartridge in vertical filters, and there are few studies on the cleaning performance of elliptical horizontal cartridge filters. In this study, the effects of different venturis on the pressure drop of dust collector and the static pressure acting on the inner wall of the elliptical filter cartridge were investigated through numerical simulation and experiment. When the venturi throat diameter is 160 mm, the minimum pressure drop and the maximum peak pulse pressure of the inner wall can be obtained. The mechanism of venturi improving collection efficiency of elliptical filter cartridge is revealed by the flow field analysis method. The magnitude of peak pressure P1 to P3 are about 1.4–2.7, 1.1–1.7 and 1.1–1.4 times that of without venturi. The injection distance and pulse-jet tank pressure can be reduced by venturi. The results are helpful for the design and improvement of pulse-jet cleaning horizontal cartridge filters.

Determination of the Configurations of Boundaries in Space

AbstractThis research aims to determine the geometrical configurations of boundary surfaces in the space environment, based on multiple spacecraft measurements. To achieve this, the Normal Field Analysis (NFA) method is presented here. With multipoint observations, the three‐dimensional gradient of the normal of boundary layers can be obtained, and the principal curvatures and principal directions of the surfaces can be deduced. The correctness of the method is then verified. Two initial applications have been carried out. The first is to determine the geometrical features of the Earth's bow shock where it is found that, with a one‐dimensional approximation, the surface of the bow shock has a rotational conicoid shape with eccentricity about 0.82, consistent with previous studies. Second, the method is also used to analyze two magnetotail dipolarization fronts showing that the dipolarization fronts are hyperbolic paraboloids or saddle surfaces with negative Gaussian curvatures. The south‐north scale of the dipolarization fronts is about 0.835–3.98 RE, and the dawn‐dusk/azimuthal scale is about 1.58–1.92 RE, confirming previous studies. The method presented can also be applied to investigate the geometries of the magnetopause, plasmapause, and other boundaries.

2D AND 3D QSAR ANALYSIS OF IMIDAZOLE DERIVATIVES AS HEME OXYGENASE INHIBITOR

Selective inhibition of heme oxygenase is an important strategy in design of potent inhibitors of enzyme for the treatment of neonatal jaundice, cancer and many more. QSAR analysis is employed for a given set of compounds containing imidazole pharmacophore in order to establish a relationship between the biological activity and related descriptors, which provides us an idea to gain a potent inhibitor with lesser side effects. In this paper we present results of 2D and 3D QSAR studies of series of 26 molecules containing imidazole pharmacophore as selective heme oxygenase inhibitor using V Life MDS 3.5 Software. The 2D QSAR studies was performed using Partial Least Square Regression method and the 3D QSAR studies was performed using k- Nearest Neighbor Molecular Field Analysis(kNN- MFA) method. The analysis has produced good predictive and statistically significant QSAR models. 2D QSAR studies produced good statistical model with r2 value 0.8487, cross validated r2 value 0.6553 and prd_r2 value 0.7478 by PLSR method while 3D QSAR model gave statistical value of cross validated r2 value 0.5493 and pred_r2 value 0.3358. The results of the QSAR analysis suggested that the 2-D descriptor viz. physicochemical and alignment independent played an important role for heme oxygenase inhibition and the 3-D descriptors electrostatic and steric revealed the relative positions and range for substitution in a molecule. In 3D model, grid suggested that a positive electrostatic potential is favorable for increase in biological activity and the steric field with negative range and the negative range indicates that negative steric potential is favorable for increase in the activity. Thus, the descriptors generated by 2-D and 3-D QSAR analysis were useful in designing of potent molecules.

In silico design novel (5-imidazol-2-yl-4-phenylpyrimidin-2-yl)[2-(2-pyridylamino)ethyl]amine derivatives as inhibitors for glycogen synthase kinase 3 based on 3D-QSAR, molecular docking and molecular dynamics simulation

Glycogen Synthase Kinase 3 (GSK-3) is a member of cellular kinase with various functions, such as glucose regulation, cellular differentiation, neuronal function and cell apoptosis. It has been proved as an important therapeutic target in type 2 diabetes mellitus and Alzheimer's disease. To better understand their structure–activity relationships and mechanism of action, an integrated computational study, including three dimensional quantitative structure-activity relationship (3D-QSAR), molecular docking, and molecular dynamics (MD), was performed on 79 (5-Imidazol-2-yl-4-phenylpyrimidin-2-yl)[2-(2-pyridylamino)ethyl]amine GSK-3 inhibitors. In this paper, we constructed 3D-QSAR using comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) method. The results showed that the CoMFA model (q2 = 0.743, r2 = 0.980) and the CoMSIA model (q2 = 0.813, r2 = 0.976) had stable and reliable predictive ability. The electrostatic and H-bond donor fields play important roles in the models. The contour maps of the model visually showed the relationship between the activity of compounds and their three-dimensional structure. Molecular docking was used to identify the key amino acid residues at the active site of GSK-3 and explore its binding mode with ligands. Based on 3D-QSAR models, contour maps and the binding feature between GSK-3 and inhibitor, we designed 10 novel compounds with good potential activity and ADME/T profile. Molecular dynamics simulation results validated that Ile62, Val70 and Lys85 located in the active site play a key role for GSK-3 complexed with inhibitors. These results might provide important information for designing GSK-3 inhibitors with high activity.

Locally implicit time-domain finite element method for sound field analysis including permeable membrane sound absorbers

Locally implicit time-domain finite element method for sound field analysis including permeable membrane sound absorbers

Transient Temperature Distribution and Thermo-Mechanical Coupling Response of Paper in the Fusing Process of Laser Printers

AbstractThe hot-press fusing process of a laser printer is one of the principal causes for paper folding and bending deformation. In order to predict and control the deformation of paper, first, the following analysis method is proposed for the transient temperature field analysis of the continuous moving paper: discretizing the thermal analysis process, replacing the moving paper model with the moving heat source, and simulating the movement speed of paper by setting the flow boundary conditions. Second, taking the steady-state thermal calculation results of the printer in the standby mode as initial conditions, the temperature distribution characteristics of paper during the movement are obtained with the paper model placed in a whole-machine environment to analyze the transient temperature field. Third, using the method of multi-field coupling, the transient temperature field results of paper are taken as the external load of its static analysis to analyze the deformation of paper during the fusing process; therefore, the quantitative deformation results and deformation characteristics of paper after fusing are obtained. According to the results, more precise boundary conditions can be achieved by calculating the temperature field of paper in a whole-machine environment. The method of transient temperature field analysis for continuous moving objects proposed in this study can effectively simulate the movement process of paper. The results reveal the mechanism of paper wrinkle and bending deformation in the fusing process, which can be used to predict the conveying performance of paper and guide the design work of the printer.

Microphone and Loudspeaker Array Signal Processing Steps towards a “Radiation Keyboard” for Authentic Samplers

To date electric pianos and samplers tend to concentrate on authenticity in terms of temporal and spectral aspects of sound. However, they barely recreate the original sound radiation characteristics, which contribute to the perception of width and depth, vividness and voice separation, especially for instrumentalists, who are located near the instrument. To achieve this, a number of sound field measurement and synthesis techniques need to be applied and adequately combined. In this paper we present the theoretic foundation to combine so far isolated and fragmented sound field analysis and synthesis methods to realize a radiation keyboard, an electric harpsichord that approximates the sound of a real harpsichord precisely in time, frequency, and space domain. Potential applications for such a radiation keyboard are conservation of historic musical instruments, music performance, and psychoacoustic measurements for instrument and synthesizer building and for studies of music perception, cognition, and embodiment.

Profiling the Structural Determinants of Aryl Benzamide Derivatives as Negative Allosteric Modulators of mGluR5 by In Silico Study.

Glutamate plays a crucial role in the treatment of depression by interacting with the metabotropic glutamate receptor subtype 5 (mGluR5), whose negative allosteric modulators (NAMs) are thus promising antidepressants. At present, to explore the structural features of 106 newly synthesized aryl benzamide series molecules as mGluR5 NAMs, a set of ligand-based three-dimensional quantitative structure-activity relationship (3D-QSAR) analyses were firstly carried out applying comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods. In addition, receptor-based analysis, namely molecular docking and molecular dynamics (MD) simulations, were performed to further elucidate the binding modes of mGluR5 NAMs. As a result, the optimal CoMSIA model obtained shows that cross-validated correlation coefficient Q2 = 0.70, non-cross-validated correlation coefficient R2ncv = 0.89, predicted correlation coefficient R2pre = 0.87. Moreover, we found that aryl benzamide series molecules bind as mGluR5 NAMs at Site 1, which consists of amino acids Pro655, Tyr659, Ile625, Ile651, Ile944, Ser658, Ser654, Ser969, Ser965, Ala970, Ala973, Trp945, Phe948, Pro903, Asn907, Val966, Leu904, and Met962. This site is the same as that of other types of NAMs; mGluR5 NAMs are stabilized in the “linear” and “arc” configurations mainly through the H-bonds interactions, π–π stacking interaction with Trp945, and hydrophobic contacts. We hope that the models and information obtained will help understand the interaction mechanism of NAMs and design and optimize NAMs as new types of antidepressants.

Electromagnetic Sensor for Detecting Wear Debris in Lubricating Oil

The detection technology on wear debris in lubricating oil is critical to ensure the safe operation of the engines in the aerospace industry. In this article, a triple-coil reverse double-excitation solenoid sensor is discussed. Inside the sensor, electromagnetic field generated by two excitation coils is sensitive to the occurrence of wear debris, and its changes can be captured by the induction coil. Thus, the impedance and inductive voltage of the induction coil can be used to detect the wear debris. Assuming the debris is spherical, an electromagnetic model is established. Via time-harmonic electromagnetic field analysis method, the expressions of the induction coil’s impedance increment and inductive voltage are derived. The relationships between the impedance increment and the parameters of the debris and the coils are investigated. The theoretical results are validated by Maxwell from Ansys, Canonsburg, PA, USA, simulations and experiments. In order to get an accurate voltage output signal, a passband filter amplifier is designed to connect to the output of the induction coil and empirical mode decomposition is presented to process the digital voltage signal. The derivation method on the coil impedance increment and inductive voltage and the signal processing method can be extended to design sensors measuring more complicated wear debris.

Numerical analysis of planar multimode optical sensor with active nanolayer

In the paper, numerical studies of the model of an optical sensor, based on interference of modes in a planar one-dimensional step-index configuration, are presented. Calculations are performed using the method of mode field analysis. The structure consists of the single-mode input waveguide, the multimode waveguide that guides only a few modes and the single-mode output waveguide. The structure is covered by a nanometer active sensor layer of a high refractive index, which changes its optical properties in contact with the measured external surrounding. The refractive index variation of an active sensor layer affects the modal properties of the multimode waveguide and the output optical field distribution. By the proper selection of the active layer, the considered configuration can be used for gas detection.

Does Brexit mean Brexit? An analysis of the semantic field of the lexeme Brexit

The article presents the results of a discourse analysis of the contextual uses of Brexit. Based on corpus-driven Internet samples, the research employs the method of semantic field analysis devised by Robin (1980) and her team of researchers from the Saint-Cloud Political Lexicography Center. According to Robin, in order to find the meaning of a word, the context of its use must be analysed, as well as its lexical relations with other linguistic units. For this reason, we have divided the elements of the co-text of the lexeme Brexit into six groups, which represent various connections of linguistic items with the SUBJECT, i.e. the lexeme under scrutiny. Subsequently, in compliance with Kłosiński’s approach (1994), we propose the definitions of the SUBJECT which reflect the meanings featuring the actual usages of the lexeme Brexit and which integrate the key words from the semantic field of the concept in question.

Investigation of angiotensin-I-converting enzyme (ACE) inhibitory tri-peptides: a combination of 3D-QSAR and molecular docking simulations.

Angiotensin-I-converting enzyme (ACE) is a key enzyme in the regulation of peripheral blood pressure and electrolyte homeostasis. Therefore, ACE is considered as a promising target for treatment of hypertension. In the present work, in order to investigate the binding interactions between ACE and tri-peptides, three-dimensional quantitative structure–activity relationship (3D-QSAR) models using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) methods were developed. Three different alignment methods (template ligand-based, docking-based, and common scaffold-based) were employed to construct reliable 3D-QSAR models. Statistical parameters derived from the QSAR models indicated that the template ligand-based CoMFA (Rcv2 = 0.761, Rpred2 = 0.6257) and CoMSIA (Rcv2 = 0.757, Rpred2 = 0.6969) models were better than the other alignment-based models. In addition, molecular docking studies were carried out to predict the binding modes of the peptides to ACE. The peptide–enzyme interactions were consistent with the derived 3D contour maps. Overall, the insights gained from this study would offer theoretical references for understanding the mechanism of action of tri-peptides when binding to ACE and aid in the design of more potent tri-peptides.

PROBLEMS OF THE EXPRESSION OF CONDITIONAL RELATIONSHIPS IN THE UZBEK LANGUAGE

The article is aimed at investigating the problems of the expression of conditionals in the Uzbek language. Particularly, in the article a special emphasis is placed on the analysis of peculiarities of formal expressions of conditionals in the Uzbek language. The objectives of the research are formed by defining the notion of condition in Uzbek, studying the forms of expression of the conditionals, analyzing the syntactic structure of the conditional constructions, identifying the levels of language in which conditionals are expressed, analyzing the functions of conjunctions connecting the clauses of conditional sentences and identifying the stylistic features of conditional conjunctions. Linguistic description, generalization of prior ideas and theories in the field and componential analysis methods are used. The results of the study have shown that the conditionals are expressed by the synthetic and analytic forms, the synthetic forms (conditionals formed by affixes) refer to the conditional forms constructed by adding the conditional affix “-sа” to the stem of the verb, the analytic forms (the combination with two or more components) include the form of“-sа”+ to’liqsiz fe’l (an auxiliary verb (edi, ekan, emish), the combination of a part of speech which is not a verb+bo’l (to be)+sa, lexical units as desa, bo’lsa, yo’qsa and proverbs. The conditionals are mainly expressed at the grammatical and lexical levels of the language. In the grammatical layer, the conditionals are especially expressed through a syntactic unit which is a complex sentence and it is important to note the role of the conditional affix “-sa” in expressing a condition at the morphological level. In the lexical layer, some lexical units and proverbs can be regarded as means of expressing conditionality. Also,conditional clauses are connected by various conjunctions (agar, basharti, mabodo, bordiyu, madomiki all referring to “if” in English) and these connectives possess different stylistic colorings and the main function of such conjunctions is not to express conditionality, but to emphasize and exaggerate a conditional meaning. So, the structural peculiarities of conditionals in Uzbek are determined by their syntactic structure, their expression in different language levels and the conditional conjunctions.

Mythonym Orpheus as an Element of V.Ya. Bryusov’s Code

This article sets out to carry out linguocognitive characterization of the mythonym Orpheus as an element of V.Ya. Bryuso v’s code. The investigation of the author’s code involved the use of the field analysis method aimed at identifying the place of a language unit under study in the author’s worldview, which is organized by the author’s individual code. The study is based on the material of Bryuso v’s poem «Uchenik Orfeya» («Orpheus’s student»), where this mythonym exhibits ideological and aesthetic dominance. The text analysis indicates that, in the work of Bryusov, Orpheus performs the function of a literary concept, the meaning component of which is represented by lexical items and established phrases describing the singer’s fate, while the emotional and expressive components are manifested by elements of sub- ject-thematic educational, landscape, animated, temporal, human codes.