Power Equation Research Articles

Прогнозування параметрів кузовних машин для внесення твердих органічних добрив

The purpose of the article was to substantiate the trend of changing the basic mass and dimensional parameters of body machines for the application of solid organic fertilizers depending on their capacity. The analysis of constructions of machines of production by the enterprises in the territory of the former Soviet Union and modern Ukraine is carried out. The research methods were based on the study of the main consumer parameters of machines using the information provided in the Catalogs of agricultural machinery and advertising information of enterprises-manufacturers of body machines. Processing and generalization of the collected data is carried out on the basis of correlation-regression analysis and using standard computer programs. The load-bearing capacity of the machines was taken as a factorial feature in the study, and their weight and overall length, width and height were taken as effective. The range of variation, arithmetic mean, standard deviation and coefficient of variation of factorial and performance characteristics are determined. There is a positive correlation between the mass of body machines, their overall length, width and height and load capacity of the machines with correlation coefficients of 0.959, respectively; 0.9000; 0.721 and 0.864 for correlation ratios of performance traits to factorial in the same sequence 0.960; 0.862; 0.859 and 0.840. According to certain correlation indicators, depending on the load capacity of the machines, the effective characteristics should increase. To finally clarify the nature and form of communication, the experimental values of the performance characteristics were aligned depending on the load capacity of the machines by the equations of direct power and logarithmic functions and exponents and hyperbolas. According to the calculated R2-coefficients, the best approximation to the experimental values of machine mass and overall length and height was provided by approximation of their change depending on load capacity by equations of lines with positive angular coefficients, and to experimental values of dimensional width by approximation of. It was found that depending on the load capacity of machines, their overall lengths and heights increase in a straight line with certain angular coefficients. The change in the overall width of the body machines for the application of solid organic fertilizers depending on the load capacity of the machines is described by the equation of increasing hyperbola.

Three-Dimensional Study of the Effect of the Angle of Incidence of a Magnetic Field on the Electrical Power and Conversion Efficiency of a Polycrystalline Silicon Solar Cell under Multispectral Illumination

A three-dimensional approach to the effect of magnetic field incidence angle on electrical power and conversion efficiency is performed on a front-illuminated polycrystalline silicon bifacial solar cell. A solution of the continuity equation allowed us to present the equations of photocurrent density, photovoltage and electric power. The influence of the angle of incidence of the magnetic field on the photocurrent density, the photovoltage and the electric power has been studied. The curves of electrical power versus dynamic junction velocity were used to extract the values of maximum electrical power and dynamic junction velocity and to calculate those of conversion efficiency. From this study, it is found that the conversion efficiency values increase with the angle of incidence of the magnetic field.

Об экспериментальном определении параметров интенсивности 4f-4f-переходов по спектрам излучения соединений европия (III)

Eu3+ complexes and specially β-diketonate compounds are well known and studied in several areas due to their luminescence properties, such as sensors and lightning devices. A unique feature of the Eu3+ ion is the experimental determination of the 4f-4f intensity parameters Ωλ directly from the emission spectrum. The equations for determining Ωλ from the emission spectra are different for the detection of emitted power compared to modern equipment that detects photons per second. It is shown that the differences between Ωλ determined by misusing the equations are sizable for Ω4 (ca. 15.5%) for several Eu3+β-diketonate complexes and leads to differences of ca. 5% in the intrinsic quantum yields Q_Ln^Ln. Due to the unique features of trivalent lanthanide ions, such as the shielding of 4f-electrons, which lead to small covalency and crystal field effects, a linear correlation was observed between Ωλ obtained using the emitted power and photon counting equations. We stress that care should be exercised with the type of detection should be taken and provide the correction factors for the intensity parameters. In addition, we suggest that the integrated intensity (proportional to the areas of the emission band) and the centroid (or barycenter) of the transition for obtaining Ωλ should be determined in the properly Jacobian-transformed spectrum in wavenumbers (or energy). Due to the small widths of the emission bands of typical 4f-4f transitions, the areas and centroids of the bands do not depend on the transformation within the experimental uncertainties. These assessments are relevant because they validate previously determined Ωλ without the proper spectral transformation.

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Eu3+ complexes and specially β-diketonate compounds are well known and studied in several areas due to their luminescence properties, such as sensors and lightning devices. A unique feature of the Eu3+ ion is the experimental determination of the 4f-4f intensity parameters Ωλ directly from the emission spectrum. The equations for determining Ωλ from the emission spectra are different for the detection of emitted power compared to modern equipment that detects photons per second. It is shown that the differences between Ωλ determined by misusing the equations are sizable for Ω4 (ca. 15.5%) for several Eu3+β-diketonate complexes and leads to differences of ca. 5% in the intrinsic quantum yields Q_Ln^Ln. Due to the unique features of trivalent lanthanide ions, such as the shielding of 4f-electrons, which lead to small covalency and crystal field effects, a linear correlation was observed between Ωλ obtained using the emitted power and photon counting equations. We stress that care should be exercised with the type of detection should be taken and provide the correction factors for the intensity parameters. In addition, we suggest that the integrated intensity (proportional to the areas of the emission band) and the centroid (or barycenter) of the transition for obtaining Ωλ should be determined in the properly Jacobian-transformed spectrum in wavenumbers (or energy). Due to the small widths of the emission bands of typical 4f-4f transitions, the areas and centroids of the bands do not depend on the transformation within the experimental uncertainties. These assessments are relevant because they validate previously determined Ωλ without the proper spectral transformation.

A Spatial Geometric Nonlinearity Spline Beam Element With Nodal Parameters Containing Strains

Many slender robs in engineering can be abstracted as Euler-Bernoulli beams. When analyzing their dynamic behavior, it is necessary to establish the dynamic model of the flexible multi-body systems. Geometric nonlinear elements with absolute nodal coordinates solved a large number of dynamic problems of flexible beams, but it still faces such problems as shear locking, discontinuity of nodal stress and low computational efficiency. In this paper, based on the theory of large deformation beam’s virtual power equation, the functional formula between displacements and rotation angles located at the nodes were established, which can satisfy the deformation coupling relationships and the generalized strains that can describe geometric nonlinear effects in this case were derived. Some parameters of boundary nodes were replaced by axial strain and sectional curvature to obtain a more accurate and concise constraint method for applying external forces. In order to improve the numerical efficiency and stability of the system’s motion equations, a model smoothing method was used to filter out high frequencies from the model. The rationality and effectiveness of the proposed unit were verified.

ИСПОЛЬЗОВАНИЕ ЛОГАРИФМИЧЕСКОГО И СТЕПЕННОГО УРАВНЕНИЙ ДЛЯ ПРОГНОЗА ОБЪЕМА ПЕРЕВЕЗЕННЫХ ГРУЗОВ АВТОМОБИЛЬНЫМ ТРАНСПОРТОМ В САНКТ-ПЕТЕРБУРГЕ

The article presents an analysis of the transported goods by motor transport of St. Petersburg and their forecast until 2030 using the Trend Line program, which is included as the MS Excel database software. This analysis was based on statistical data for the period from 2000 to 2020. The obtained equations showed that the logarithmic and power equations should be used in the forecast, on the basis of which the analysis was carried out until 2030.

ADJUSTMENT OF MATHEMATICAL MODELS TO DETERMINE QUALITY CHARACTERISTICS OF PINEAPPLE FRUITS VITÓRIA CULTIVAR

The objective of this study was to adjust and validate mathematical models to estimate physical and chemical characteristics of pineapple fruits (Ananas comosus L.) through their linear dimensions. For this purpose, 130 fruits of the cultivar BRS Vitória were used, produced at the experimental farm of the Capixaba Institute of Research, Technical Assistance and Rural Extension, located in the municipality of Sooretama, North of the State of Espírito Santo, Brazil. Of all fruits, the length (L), diameter (D), mass (M), titratable acidity (TA) and soluble solids (SS) were determined. For the modeling, the characteristics M, TA and SS were used as a dependent variable in function of L and D of the fruits, being adjusted the models of equation of first degree linear, quadratic and power. All equations were valid, thus obtaining the mean absolute error, root mean square error and Willmott d index. The diameter showed a better relationship with the physical and chemical characteristics of the pineapple fruit cultivar BRS Vitória, the equations being y = 0.0015(D)^2.7451, y = 1.076350-0.261046(D)+0.018081(D)^2 e y = 21.91682-4.58785(D)+0.31048(D)^2 more suitable for estimating the mass, titratable acidity and soluble solids respectively, in a simple, safe and without the need to destroy the fruits.

Optimization of super-Gaussian thulium-doped fiber amplifier for S-band multimode division multiplexing

We have assigned the first four linear polarized (LP) modes of signals at the wavelength of 1470 nm as four channels of multimode division multiplexing (MDM) structure and for each channel we have used a few-mode thulium doped fiber amplifier (FM-TDFA) consisting a pump at the wavelength of 1050 nm and a few-mode thulium doped fiber (FM-TDF). The operation of each FM-TDFA has been investigated by changing the three parameters of super-Gaussian transverse distribution of FM-TDF in the presence of different kinds of LP modes of pumping with several values of input pump power. We have searched the whole space of variables through computation of the rate and power equations and calculated the overlap factors, gain and noise figure (NF) for each point of the space to find the global optimum condition. Also, we have found the best FM-TDFAs configurations by the average gain of 39.2 dB and average NF of 3.24 dB.

Characterisation of geomembrane and geotextile interface short-term creep behaviour in a dry condition

This study aims to characterise the interface creep behaviour between geomembrane and geotextile (i.e. GM-GT) in the liner system. Two types of GM (i.e. smooth SGM and textured TGM) and two types of GT (i.e. nonwoven NWGT and woven WGT) were investigated using the conventional direct shear apparatus for four combinations of GM-GT. The interface friction angles (φin) between GM-GT were firstly determined at the normal stresses (σn) of 25, 50, 100 and 200 kPa. The results show that TGM-NWGT has a much larger φin (23.9°) than the other three combinations which ranged from 9.5° to 11.1°. Subsequently, creep tests were conducted at three shear stress (τ) levels (i.e., 30, 50 and 70% of the peak stress (τp) under each normal stress). The creep test results of the four combinations were analysed and a power equation of time was used to estimate creep displacement (δcp). The coefficients A and B in the power equation were found to be functions of Young's modulus of the composite material (Ec), time, σn, τ, τp, and φin. The tertiary creep stage was not observed in the test and it is recommended that longer duration GM-GT interface creep tests should be conducted for in-depth understanding of the interface creep mechanism.

Spatial distribution of <i>Aphidius matricariae</i> (Haliday) and <i>Myzus persicae</i> (Sulzer) in bell pepper under polyhouse conditions

The spatial distribution of Aphidius matricariae and Myzus persicae was studied in bell pepper under polyhouse conditions. In the present study, M. persicae and its parasitoid, A. matricariae populations followed negative binomial distribution throughout the season. The variance to mean ratio (σ2/X), mean crowding (X*), ratio of mean crowding to mean (X*/X), ‘k’ of negative binomial, Taylor’s power equation for M. persicae and A. matricariae were σ² = 6.97X1.531 (R2 = 0.931), and σ² = 4.29X1.282 (R2 = 0.90) during 2018-2019, respectively. Iwao’s patchiness regression was X* = 45.12 + 1.333X (R2 = 0.853), and X* = 5.406 + 1.195X (R2 = 0.767) during 2018-2019, respectively. Optimum number of samples required for the green peach aphid, M. persicae and A. matricariae were 261.1 and 474 at 20% precision level. The present study will be useful for developing a sampling plan of M. persicae and its parasitoid, A. matricariae in bell pepper for its monitoring and management.

Rates, factors, and tolerances of water erosion in the Cerrado biome (Brazil): A meta‐analysis of runoff plot data

AbstractDue to the high rainfall erosivity and highly erodible soils, water erosion is severe in Brazil. Soil and ecosystem degradation occurs when erosion exceeds on‐ and off‐site soil loss tolerances, with significant socioeconomic and environmental impacts. In the last 50 years, the Brazilian Cerrado had 53% of its original vegetation converted to agriculture and pastureland. Although erosion plot studies exist in the region, the data are fragmented and unexplored, hindering the development of soil conservation policies. The objective of the present research was to compile, systematize, and statistically analyze the existing erosion plot data in the Brazilian Cerrado, correlating the observed results with different environmental and management factors, and with the corresponding soil loss tolerances. Twenty runoff plot datasets of the Brazilian Cerrado, encompassing 5 states, 10 sites, 108 plots, and 360 plot·years were compiled and thoroughly analyzed. Mean annual rainfall, runoff, and soil loss were 1443.5 mm year−1, 83.1 mm year−1, and 8.9 Mg ha−1 year−1, respectively. After the data were normalized with respect to plot length, steepness, and climate, runoff and soil loss were found to be significantly higher in soils with impermeable horizons and in land uses without permanent soil cover (p < 0.05). Erosion under permanently covered plots was below the on‐ and off‐site soil loss tolerances. A power equation provided the best fit between plot runoff and soil loss (R2 = 0.71; p < 0.05), indicating that runoff volume, easier to estimate, could be used as a proxy for upslope erosion. Although erosion plot data cannot be extrapolated to the whole landscape, the research results provide useful elements for the development of sound conservation policies in the Cerrado and in other similar savannas of the world.

ANALYSIS OF THE DISTRIBUTION OF SALINITY VALUE AND SEA SURFACE TEMPERATURE IN LAMONG BAY WATERS, GRESIK REGENCY


 
 
 
 The waters of Teluk Lamong are located on the north sea coast of Surabaya, which is directly adjacent to the Gresik Regency. Lamong Bay is famous as a strategic port place on an International scale. Along the coastal waters of Teluk Lamong, some rivers flow in Lamong Bay. These activities can lead to interaction between fresh water and seawater. This interaction affects the pattern of salinity spread and sea surface temperature in the waters of Teluk Lamong. Salinity and Sea Surface Temperature is one of the biggest factors causing corrosion in the sea that will damage the structure of buildings around the sea. It is expected that in this research as information about the waters of Teluk Lamong for data information or database utilization in the field of civil engineering, among others, port maintenance and coastal building planning. Based on this background, research is needed to monitor the spread of salinity values and sea surface temperatures in Lamong Bay using Landsat 8 satellite imagery for the years 2016 and 2020. The result of modeling the algorithm obtained, the model of the algorithm used to process the salinity of the image is the wavelength Band_4 in the Equation Power with the model algorithm y = 25.437x-0.046, and the degree of determination value R² = 0.5825. While sea surface temperature in power equation with algorithm model y = 302.14x0.0029 and determination value R² = 0.4182. The results of an analysis of the T-test and validation test can be qualified. The results of the analysis of imagery data showed salinity distribution ranged from 27.33 (ppm) to 29.9 (ppm), while sea surface temperatures ranged from 303.95 Kelvin to 304.39 Kelvin.
 
 
 

How Does the Gradient Measure of the Lung SBRT Treatment Plan Depend on the Tumor Volume and Shape?

PurposeGradient measure (GM) is a critical index related to normal tissue sparing in radiosurgery. This study aims to describe the dependence of GM on target volume and target shape for lung stereotactic body radiation therapy (SBRT) treatment plans.MethodsA total of 307 peripheral and 119 central lung SBRT treatment plans were enrolled for this study. A least-squares regression was used for data analysis. First, the equations with different functional forms were established to determine the dependence of GM on a univariaty (VP or Sp) and bivariaty (VP and Sp), respectively. Then, the correlation coefficients and p-values of variables for all equations were compared and analyzed to determine the dependence of GM on PTV volume (VP) and sphericity (Sp).ResultsThe power equations had the highest coefficient of determination (R2) in the dependence results of GM on univariate VP. The equations were and for peripheral and central lesions, respectively. On the other hand, the R2 of all functional forms were less than 0.25 when the relationship of GM versus univariate Sp was analyzed. Similarly, the power equation also obtained the highest R2 in bivariaty VP and Sp analysis, whether for central or peripheral. However, the R2 of the bivariate equations were not improved compared with those of univariate equations. Moreover, the p-values of the variable Sp were greater than 0.05.ConclusionsThe GM of the lung SBRT plan is shape-independent and volume-dependent. The dependence of GM on PTV volume for peripheral and central lung cancer can be described by two different power equations. The results of this study can be used as a potential tool to assist dosimetric quality control during the radiosurgery process.

Design and verification of a novel double rotor without stator wind turbine generation system

The operation condition of wind turbine is complex with frequent load disturbances. However, the traditional rigid connection wind turbine has shortcomings in rejecting impact load disturbance. In this paper, a novel double rotor wind turbine generation system is proposed. Firstly, the concept design of the new system is carried out by adopting the technical route of ”double rotor machine + electrically excited synchronous generator”, and the main components and structural forms of the system are given. Then, the balance equations of speed, torque and power are derived based on the principles of kinematics and electrotechnics. Finally, the characteristics of the double rotor wind turbine generation system under different wind conditions are analyzed through simulation, where the anti-impact load capacity is evaluated. The simulation results show the superiority of the proposed novel double rotor wind turbine generation system.

A 200-GHz Power Amplifier With a Wideband Balanced Slot Power Combiner and 9.4-dBm P sat in 65-nm CMOS: Embedded Power Amplification

The effect of gain and embedding of amplifying cells (amp-cell) on the output power of power amplifiers (PAs) at high mm-wave frequencies is studied. This is the frequency range where matching loss becomes comparable with the gain of the amp-cell in most silicon technologies. By deriving power equations of embedded amp-cell, power contours are plotted in the gain plane and an optimum embedding is designed to maximize the output power for a desired gain. To showcase the theory, a high-frequency, high-power amp-cell, called matched cascode, is introduced and subsequently embedded to boost both power gain and output power. To increase the output power even further, a differential slot power combiner (SPC) is introduced and its equivalent circuit is analyzed. Finally, using the embedded matched cascode cell, and the SPC, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2 \times 8$ </tex-math></inline-formula> PA is implemented in 65-nm bulk CMOS. It consumes 732 mW from 2.4-V supply voltage, with a maximum power-added efficiency (PAE) of 1.03%. The PA features a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\text {sat}}$ </tex-math></inline-formula> and OP1dB of 9.4 and 6.3 dBm, respectively, at 200 GHz, and a maximum power gain of 19.5 dB.

Development of higher-order displacement discontinuity method to simulate fatigue crack growth in brittle materials

The 2D displacement discontinuity method (2D. DDM) is an indirect boundary element technique in which the stresses and displacements are expressed through normal and shear displacement discontinuities. The governing equations of fatigue crack growth are mostly power equations that depend on the stress intensity factor range. Accurate calculation of displacement discontinuity has importance in fatigue analysis of DDM. Therefore, in this study, DDM is extended using cubic variations of displacement discontinuity for ordinary and crack tip elements. This method also uses an appropriate algorithm based on the linear elastic fracture mechanics (LEFM) principle to analyze crack growth under cyclic fatigue loading. This process is accomplished by assuming the homogeneity of brittle material and the small plastic zone of the crack tip compared to the crack dimension. The condition of applying constant and stationary variable amplitude loading was provided. The algorithm is designed based on an iterative process, and the new incremental elements gradually are added to the crack tip until the failure criteria are reached; The size of these elements at each step of growth depends on the crack growth rate in the previous step. Therefore, the fatigue modeling of the structures with multiple cracks and different growth rates is enabled. Virtual crack criteria were employed to improve the accuracy and speed of analysis, which involves crack tips with a slower growth rate. Moreover, the direction of crack propagation is evaluated using the maximum circumferential stress criterion. Examples of simple and multi-fractured structures under constant and variable amplitude load are considered. Comparison of results with literature data shows excellent agreement with high accuracy.

Effects of Biochar Addition on Rill Flow Resistance

The development of rills on a hillslope whose soil is amended by biochar remains a topic to be developed. A theoretical rill flow resistance equation, obtained by the integration of a power velocity distribution, was assessed using available measurements at plot scale with a biochar added soil. The biochar was incorporated and mixed with the arable soil using a biochar content BC of 6 and 12 kg m−2. The developed analysis demonstrated that an accurate estimate of the velocity profile parameter Гv can be obtained by the proposed power equation using an exponent e of the Reynolds number which decreases for increasing BC values. This result pointed out that the increase of biochar content dumps flow turbulence. The agreement between the measured friction factor values and those calculated by the proposed flow resistance equation, with Гv values estimated by the power equation calibrated on the available measurements, is characterized by errors which are always less than or equal to ±10% and less than or equal to ±3% for 75.0% of cases. In conclusion, the available measurements and the developed analysis allowed for (i) the calibration of the relationship between Гv, the bed slope, the flow Froude number, and the Reynolds number, (ii) the assessment of the influence of biochar content on flow resistance and, (iii) stating that the theoretical flow resistance equation gives an accurate estimate of the Darcy–Weisbach friction factor for rill flows on biochar added soils.

Hi-Tech-Oriented National Service: The Free Choice of Religious Women Recruits and the De-Monopolization of the Israeli Military

In recent years, Israel has witnessed two significant processes that challenge the dominant republican discourse that prioritizes military over national-civic service (known as The Israeli national-civilian service—NCS)in terms of contributing the constitution of citizenship and of the material and symbolic convertibility offered to service candidates. The first is related to the expanding range of roles offered in the NCS. The second, related process, which is our current focus, occurs among young religious women from the urban upper-middle class who respond to this expansion by seeking to serve in technological roles, given their high qualifications. Combined, these processes transform the status of the NCS and accelerate the de-monopolization of military service. To examine the contribution of religious young women to the change in the status of service in Israel, we conducted a narrative analysis of interviews with service candidates. Our analysis revealed their strategic use of four different discourses: the neo-liberal economic discourse, the liberal rights and self-realization discourse, the ethnonational discourse, and the religious gender discourse. The way the participants negotiated the four discourses to justify their selection of either military or national-civic service structured their agency as actors transforming the power equation between the two types of service.

Design and Analysis of Dual‐Stator Brushless Doubly‐Fed Generator for Wind Turbine

Brushless doubly‐fed generator (BDFG) is a most promising candidate for the wind turbine due to its simple structure, high reliability, and low converter capacity. To improve space utilization and achieve higher power density, this paper proposes a new dual‐stator BDFG (DS‐BDFG), which provides two separated windings, namely, the power winding (PW) placed in the outer stator and the control winding (CW) placed in the inner stator. A cup‐shaped rotor sandwiched between the inner and outer stators consists of the short‐circuited coil and the salient‐pole core. The coupling between the PW and the CW is realized via the rotor based on the general airgap magnetic field modulation theory for electrical machines. A prototype of the DS‐BDFG with rated PW power of 7.2 kW is designed and optimized. The keys of this paper are the power equation derivation, the determination of pole/slot combinations, and the rotor optimization. The electromagnetic characteristics and unbalanced magnetic force of the DS‐BDFG are analyzed by 2D finite element analysis to verify the reasonableness of the proposed model. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Method for calculating the resistance of an asynchronous squirrel cage motor according to passport data and estimation of its error

A simpler method is proposed for determining the resistances of an induction motor (total inductive resistance, active resistance of the stator and reduced active resistance of the rotor) according to reference data. Three algebraic equations are obtained from the equations of reactive power dissipation and electromagnetic power in the nominal mode and the equation of electromagnetic power in the critical mode: the first is relative to three resistances, the second is the equation of the dependence of the active resistance of the stator relative to the total inductive resistance, and the third is the active resistance of the rotor relative to the total inductive resistance. An iterative method is proposed for solving this system of equations, which gives a small error already at the second step of the calculations.&#x0D; When assessing the error of the method, the specified values ​​of the electromagnetic power and the multiplicity of the maximum torque were used, which are expressed relative to the reference resistances of the control motors. An estimate is given of the total error from the imperfection of the method and the discrepancy between the reference values ​​of the multiplicity of the maximum torque and power on the motor shaft with their refined values ​​calculated from the resistances from the reference book.&#x0D; Based on the calculated resistances in the nominal mode, the dependences of the active and inductive resistances of the motor are constructed using an accurate and approximate method.