Journal articles: 'Normal Flux Method (NFM)'

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Zhang, Y., R. Kitai, and K. Takizawa. "Magnetic helicity transported by flux emergence and shuffling motions." Proceedings of the International Astronomical Union 8, S294 (August 2012): 319–20. http://dx.doi.org/10.1017/s174392131300269x.

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AbstractMagnetic helicity can be transported from sub-photosphere into corona by the emergence of helical magnetic field lines and the shuffling motions of foot-points of pre-existing coronal field lines. Active region NOAA 10930 was observed by SP and NFI of SOT on board Hinode when it pass through the solar meridian. Based on these observations, we calculate magnetic helicity flow of both terms, by regarding Doppler velocity as normal velocity. The results are compared with which calculated by method proposed by Zhang et. al. (2012). Our results show that helicity injection maps calculated by both methods have similar distribution and the integration values have the same magnitude.

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Ghidaglia, Jean-Michel, and Frédéric Pascal. "The normal flux method at the boundary for multidimensional finite volume approximations in CFD." European Journal of Mechanics - B/Fluids 24, no. 1 (January 2005): 1–17. http://dx.doi.org/10.1016/j.euromechflu.2004.05.003.

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Lai, Xiang, Zhiqiang Sheng, and Guangwei Yuan. "A Finite Volume Scheme for Three-Dimensional Diffusion Equations." Communications in Computational Physics 18, no. 3 (September 2015): 650–72. http://dx.doi.org/10.4208/cicp.140813.230215a.

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AbstractThe extension of diamond scheme for diffusion equation to three dimensions is presented. The discrete normal flux is constructed by a linear combination of the directional flux along the line connecting cell-centers and the tangent flux along the cell-faces. In addition, it treats material discontinuities by a new iterative method. The stability and first-order convergence of the method is proved on distorted meshes. The numerical results illustrate that the method appears to be approximate second-order accuracy for solution.

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Zhong, Shijie, Michael Gurnis, and Gregory Hulbert. "Accurate determination of surface normal stress in viscous flow from a consistent boundary flux method." Physics of the Earth and Planetary Interiors 78, no. 1-2 (June 1993): 1–8. http://dx.doi.org/10.1016/0031-9201(93)90078-n.

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Phong, Nguyen Hong, Tran Thu Ha, F. X. Le Dimet, and Duong Ngoc Hai. "An improved numerical method for a 2D pollution water model: Direct model." Vietnam Journal of Mechanics 39, no. 4 (December 27, 2017): 339–49. http://dx.doi.org/10.15625/0866-7136/9714.

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In this paper a 2D pollution water model with an improved numerical method is considered. In order to reduce the approximation errors of the numerical scheme, a new approximation method is introduced to calculate the concentration flux between two cells (j-cell and l-cell) in the direction of the normal vector \(\vec {n}\) orthogonal to their common side. The advantage of this approximation is that the concentration flux \({\partial C}/{\partial \vec {n}}\) from j-cell to l-cell and the other one from l-cell to j-cell are only different by their signs but not by their absolute values. Therefore, the errors of concentration simulated by this scheme are reduced and less than those obtained by a normal differential implicit discretization. This improvement of the scheme will be illustrated by two test cases. In the numerical tests we will display the difference between the exact solution, the classical scheme and the proposed scheme. Numerical results demonstrate the improvement of this approach.

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Liu, Shuangbiao, Michael J. Rodgers, Qian Wang, and Leon M. Keer. "A Fast and Effective Method for Transient Thermoelastic Displacement Analyses." Journal of Tribology 123, no. 3 (June 29, 2000): 479–85. http://dx.doi.org/10.1115/1.1308010.

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Frictional heating due to the relative motion of contacting surfaces causes temperature rise and thermal distortion, which in turn affects the contact geometry and pressure distribution. A fast and effective method is presented for the calculation of the normal surface displacement of an elastic halfspace due to arbitrary transient surface heating. The method uses Fourier-transformed Green’s functions (frequency response functions), found in the closed form by using the approach of Seo and Mura and the heat conduction analyses of Carslaw and Jaeger. The frequency response functions are shown analytically to be the frequency domain representations of the Green’s functions given by Barber. The formulation for the surface normal displacement is in the form of three-dimensional convolution integrals (over surface and time) of the arbitrary transient heat flux and the Green’s functions. Fourier transforms of these convolution integrals are taken, avoiding the Green’s-function singularities and giving a simple multiplication between the transformed heat flux and the (known) frequency response functions. The discrete convolution–fast Fourier transform (DC-FFT) algorithm is applied for accurate and efficient calculations of the normal surface displacement from the frequency response functions for an arbitrary transient heat input. The combination of the frequency-domain formulation and the DC-FFT algorithm makes the solution of transient thermoelastic deformation extremely fast and convenient.

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Wang, Wei, Hang Wang, and Hamid Reza Karimi. "Study on the Characteristics of Electromagnetic Noise of Axial Flux Permanent Magnet Synchronous Motor." Abstract and Applied Analysis 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/764105.

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The normal electromagnetic force distribution in stator system of axial flux permanent magnet synchronous motor (PMSM) has been thoroughly analyzed in this paper. The main composition of force wave causing vibration and noise has been proposed, and at the same time a calculation method of stator natural frequency of axial flux PMSM has been raised. Through this method electromagnetic force wave, natural frequency, vibration response, and electromagnetic noise of a 15 kW axial flux PMSM with 22 poles and 24 slots have been calculated; calculations and measured values are consistent by comparison. The noise sources of axial flux PMSM have been found in this paper, which provides the theoretical support for the suppression of electromagnetic noise of axial flux PMSM.

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Korpinar, T., R. Cem Demirkol, and Z. Korpinar. "New fractional Heisenberg antiferromagnetic model and solitonic magnetic flux surfaces with normal direction." International Journal of Geometric Methods in Modern Physics 18, no. 09 (May 18, 2021): 2150136. http://dx.doi.org/10.1142/s021988782150136x.

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In this paper, we study applications of fractional Heisenberg antiferromagnetic model associated with the magnetic [Formula: see text]-lines in the normal direction. Evolution equations of magnetic [Formula: see text]-lines due to inextensible Heisenberg antiferromagnetic flow are computed to construct the soliton surface associated with the inextensible Heisenberg antiferromagnetic flow. Then, their explicit solutions are examined in terms of magnetic and geometric quantities via the conformable fractional derivative method. Finally, we obtain new numerical fractional solutions for nonlinear fractional Schrödinger system with the inextensible Heisenberg antiferromagnetic flow model.

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BONNARD, B., L. FAUBOURG, and E. TRELAT. "OPTIMAL CONTROL OF THE ATMOSPHERIC ARC OF A SPACE SHUTTLE AND NUMERICAL SIMULATIONS WITH MULTIPLE-SHOOTING METHOD." Mathematical Models and Methods in Applied Sciences 15, no. 01 (January 2005): 109–40. http://dx.doi.org/10.1142/s0218202505003927.

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This article, continuation of previous works,5,3 presents the applications of geometric optimal control theory to the analysis of the Earth re-entry problem for a space shuttle where the control is the angle of bank, the cost is the total amount of thermal flux, and the system is subject to state constraints on the thermal flux, the normal acceleration and the dynamic pressure. Our analysis is based on the evaluation of the reachable set using the maximum principle and direct computations with the boundary conditions according to the CNES research project. The optimal solution is approximated by a concatenation of bang and boundary arcs, and is numerically computed with a multiple-shooting method.

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Molla, Mamun, Anwar Hossain, and Lun-Shin Yao. "Natural-Convection Flow Along a Vertical Complex Wavy Surface With Uniform Heat Flux." Journal of Heat Transfer 129, no. 10 (April 25, 2007): 1403–7. http://dx.doi.org/10.1115/1.2755062.

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A natural-convection boundary layer along a vertical complex wavy surface with uniform heat flux has been investigated. The complex surface studied combines two sinusoidal functions, a fundamental wave and its first harmonic. Using a method of transformed coordinates, the boundary-layer equations are mapped into a regular and stationary computational domain. The transformed equations can then be solved straightforwardly by any number of numerical methods designed for regular and stationary geometries. In this paper, an implicit finite-difference method is used. The results were readily obtained on a personal computer. The numerical results demonstrate that the additional harmonic substantially alters the flow field and temperature distribution near the surface. The induced velocity normal to the y axis can substantially thicken the boundary layer, implying that its growth is not due solely to the momentum and thermal diffusion normal to the y axis along a wavy surface.

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Holmberg, D. G., and T. E. Diller. "High-Frequency Heat Flux Sensor Calibration and Modeling." Journal of Fluids Engineering 117, no. 4 (December 1, 1995): 659–64. http://dx.doi.org/10.1115/1.2817319.

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A new method of in-situ heat flux gage calibration is evaluated for use in convective facilities with high heat transfer and fast time response. A Heat Flux Microsensor (HFM) was used in a shock tunnel to simultaneously measure time-resolved surface heat flux and temperature from two sensors fabricated on the same substrate. A method is demonstrated for estimating gage sensitivity and frequency response from the data generated during normal transient test runs. To verify heat flux sensitivity, shock tunnel data are processed according to a one-dimensional semi-infinite conduction model based on measured thermal properties for the gage substrate. Heat flux signals are converted to temperature, and vice versa. Comparing measured and calculated temperatures allows an independent calibration of sensitivity for each data set. The results match gage calibrations performed in convection at the stagnation point of a free jet and done by the manufacturer using radiation. In addition, a finite-difference model of the transient behavior of the heat flux sensor is presented to demonstrate the first-order response to a step input in heat flux. Results are compared with shock passing data from the shock tunnel. The Heat Flux Microsensor recorded the heat flux response with an estimated time constant of 6 μs, which demonstrates a frequency response covering DC to above 100 kHz.

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den Otter, W. K., and W. J. Briels. "The reactive flux method applied to complex isomerization reactions: Using the unstable normal mode as a reaction coordinate." Journal of Chemical Physics 106, no. 13 (April 1997): 5494–508. http://dx.doi.org/10.1063/1.473573.

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Chen, Tianyi, Jürgen Kusche, Yunzhong Shen, and Qiujie Chen. "A Combined Use of TSVD and Tikhonov Regularization for Mass Flux Solution in Tibetan Plateau." Remote Sensing 12, no. 12 (June 25, 2020): 2045. http://dx.doi.org/10.3390/rs12122045.

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Limited by the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) measurement principle and sensors, the spatial resolution of mass flux solutions is about 2–3° in mid-latitudes at monthly intervals. To retrieve a mass flux solution in the Tibetan Plateau (TP) with better visual spatial resolution, we combined truncated singular value decomposition (TSVD) and Tikhonov regularization to solve for a mascon modeling. The monthly mass flux parameters resolved at 1° are smoothed to about 2° by truncating the eigen-spectrum of the normal equation (i.e., using the TSVD approach), and then Tikhonov regularization is applied to the truncated normal equation. As a result, the terms beyond the native resolution of GRACE/GRACE-FO data are truncated, and the errors in higher degree and order components are dampened by Tikhonov regularization. In terms of root mean squared errors, the improvements are 27.2% and 12.7% for the combined method over TSVD and Tikhonov regularization, respectively. We confirm a decreasing secular trend with −5.6 ± 4.2 Gt/year for the entire TP and provide maps with 1° resolution from April 2002 to April 2019, generated with the combined TSVD and Tikhonov regularization method.

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Boon, Wietse M. "A parameter-robust iterative method for Stokes–Darcy problems retaining local mass conservation." ESAIM: Mathematical Modelling and Numerical Analysis 54, no. 6 (October 12, 2020): 2045–67. http://dx.doi.org/10.1051/m2an/2020035.

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We consider a coupled model of free-flow and porous medium flow, governed by stationary Stokes and Darcy flow, respectively. The coupling between the two systems is enforced by introducing a single variable representing the normal flux across the interface. The problem is reduced to a system concerning only the interface flux variable, which is shown to be well-posed in appropriately weighted norms. An iterative solution scheme is then proposed to solve the reduced problem such that mass is conserved at each iteration. By introducing a preconditioner based on the weighted norms from the analysis, the performance of the iterative scheme is shown to be robust with respect to material and discretization parameters. By construction, the scheme is applicable to a wide range of locally conservative discretization schemes and we consider explicit examples in the framework of Mixed Finite Element methods. Finally, the theoretical results are confirmed with the use of numerical experiments.

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Zhang, Yong, Chuanbao Jia, Jianxin Wang, Bo Zhao, and Chuansong Wu. "Investigation on the bubble dynamic behaviors and corresponding regulation method in underwater flux-cored arc welding." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 233, no. 7 (August 13, 2018): 1808–17. http://dx.doi.org/10.1177/0954405418789983.

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Observed two bubble growth modes indicated that the stability of arc burning and bubble growth relied on each other. Under selected welding parameters, the maximum diameters of generated bubbles complied with approximately normal distribution. Higher preset welding parameters generated larger bubbles with gradually receding influences. Vaporization, condensation, and reactions happened rapidly inside the bubbles even after detachment and when coming to water surface. Gas-assisted underwater flux-cored arc welding was proposed to improve the slag coverage. This method was also effective in achieving better weld appearance.

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Grove, G., and A. A. Jackson. "Measurement of protein turnover in normal man using the end-product method with oral [15N]glycine: comparison of single-dose and intermittent-dose regimens." British Journal of Nutrition 74, no. 4 (October 1995): 491–507. http://dx.doi.org/10.1079/bjn19950153.

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The ‘single-dose end-product’ approach for the measurement of protein turnover is the only method suited for application to free-living individuals and for field studies. However, the method has never been widely accepted because the results obtained appear to vary from one situation to another. There is the need for a formal comparison of the different approaches that have been used and the assumptions on which they are based in order to be able to understand the extent to which the variation in the results obtained is real or might be attributed to methodological differences. The present study used the ‘prime/intermittent-dose end-product’ approach over 18 h as a reference with which to compare the ‘single-dose end-product’ approach, with urine being collected for periods of 9 to 48 h. N flux was derived in a total of thirteen normal men using oral [15N]glycine and measurement of I5N enrichment in urinary NH3 or urea, with isotope being given either as prime/intermittent doses or a single dose in separate studies. The pattern of results was similar to those reported in the literature. In all studies the rates of N flux derived from urea were higher than those derived from NH3, under equivalent conditions, by about 25–30%. The single-dose approach, with urine collection over 9 h, gave results which were consistently higher than the prime/intermittent-dose approach. The extent of the difference was influenced by the duration of time over which the cumulative excretion of isotope in urine was determined, and with NH3 as the end-product the most consistent estimates of N flux could be obtained with a urine collection of at least 12 h and no greater than 24 h. With urea as the end-product, correction for the label retained in the body pool at 9 h gave similar results for N flux to those derived from the total excretion of label in urea over 24 h. The derivation of values for protein synthesis and protein degradation from measures of flux requires care to ensure that the time periods over which N intake and excretion are measured accord with those for which the measurement of flux apply. It is concluded that measurements of protein turnover similar to those obtained with the prime/intermittent-dose approach can be obtained with the single-dose approach in the fed state during the daytime, either from the excretion of label in urinary NH3 over a period of 12 h or with the excretion of label in urinary urea over a period of 24 h. The suitability of the method for use in the fasted state or at night time remains to be determined.

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Auchère, D., S. Tardivel, J. C. Gounelle, T. Drüeke, and B. Lacour. "Role of transcellular pathway in ileal Ca2+ absorption: stimulation by low-Ca2+ diet." American Journal of Physiology-Gastrointestinal and Liver Physiology 275, no. 5 (November 1, 1998): G951—G956. http://dx.doi.org/10.1152/ajpgi.1998.275.5.g951.

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The present study was performed to determine the respective involvement of the cellular and paracellular routes in ileal Ca2+ transport. Two groups of rats were either fed a normal Ca2+ diet (1.0%) or a Ca2+-deficient diet (0.02%) for 14 days. Ileal Ca2+absorption was determined using both an in situ method of continuous luminal perfusion and an in vitro method (Ussing chamber model). The low-Ca2+ diet stimulated net Ca2+ flux in the ileum twofold, associated with a twofold increase of the mucosal-to-serosal Ca2+ flux in both models. This effect was observed in the absence of concomitant changes in Na+ or water flux in the in situ model or mannitol flux in the in vitro model, excluding the participation of the paracellular pathway in Ca2+ transport. Thus only cellular Ca2+ flux was stimulated. These data suggest that the ileum plays a major role in the adaptation to low dietary Ca2+. Whereas under physiological conditions with usual Ca2+ intakes the transcellular pathway of Ca2+ transport is negligible, it becomes of major importance in the case of Ca2+ deficiency, at least under the present conditions of severe Ca2+ deprivation.

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Wang, Ji-Chao, Wanjing Wang, Qiang Li, Sigui Qin, Mingzhun Lei, and Guang-Nan Luo. "A method for high heat flux fatigue test of W/Cu/steel small mock-up using normal cooling conditions." Nuclear Materials and Energy 28 (September 2021): 101052. http://dx.doi.org/10.1016/j.nme.2021.101052.

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Mintun, M. A., T. E. Warfel, and D. P. Schuster. "Evaluating pulmonary vascular permeability with radiolabeled proteins: an error analysis." Journal of Applied Physiology 68, no. 4 (April 1, 1990): 1696–706. http://dx.doi.org/10.1152/jappl.1990.68.4.1696.

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Using techniques of mathematical simulation, we compared two methods of evaluating pulmonary vascular permeability, i.e., transvascular protein flux. Both methods calculate a transport rate constant [pulmonary transcapillary escape rate (PTCER)] after making external radiation detection measurements of an intravenously administered radiolabeled protein. With one method, lung tissue time-activity data are acquired by positron emission tomography (PET) and are interpreted with a two-compartment model. With the other method, the time-activity data are acquired with simple detector probes and are interpreted by linear regression after normalizing for various physical factors (slope-intercept or SI method). The results show that significant errors in calculating PTCER can result from using the SI method, because it ignores the effects of back-flux on the tissue time-activity measurements. Both methods produce errors if the data analysis includes activity from vascular volumes not involved in tracer exchange with the extravascular compartment. Significant errors can also occur with the PET method, particularly when permeability is nearly normal, if pulmonary vascular volume changes significantly during the period of data collection. On balance, the PET method appears to be the method of choice for accurately evaluating pulmonary vascular permeability by protein flux measurements, although both methods may be useful in clinical applications.

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Shams, Sadegh, Al Ghorbanpoor, Shibin Lin, and Hoda Azari. "Nondestructive Testing of Steel Corrosion in Prestressed Concrete Structures using the Magnetic Flux Leakage System." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 41 (May 14, 2018): 132–44. http://dx.doi.org/10.1177/0361198118773920.

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The Magnetic Flux Leakage (MFL) method can be nondestructively used to disclose the location and extent of corrosion or fracture in prestressed strands in concrete structures. In this study, parameters with the greatest effect on the performance of the MFL system are investigated using numerical simulations. The MFL system under study is based on two permanent magnets to magnetize embedded strands and Hall-effect sensors to detect normal magnetic flux leakage. The system is assessed using magnetostatic and transient numerical analysis to effectively simulate the MFL system. Results have been verified by laboratory and field experiments. Both normal and axial Hall-effect sensors are modeled in simulations to better identify magnetic signals at the corrosion zone. The sensor lift-off and the magnetic field masking by lateral reinforcements on nearby pitting corrosion are addressed as two main drawbacks of using MFL systems to detect corrosion in prestressed concrete structures. To provide more details about the flux leakage interference between the pitting corrosion and lateral reinforcements in prestressed concrete structures, linear and oriented magnets/sensor arrays are proposed and analyzed numerically.

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Li, Yong Gang, and Bing Han. "Magnetic Field Finite Element Analysis of Generator with Rotor Inter-Turn Short-Circuit Fault." Applied Mechanics and Materials 707 (December 2014): 343–47. http://dx.doi.org/10.4028/www.scientific.net/amm.707.343.

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Rotor inter-turn short-circuit is a common fault in generator and it is a research hotspot to identify the fault at its early stage. Considering the disadvantage of circuit analytical method, this paper establishes a 2D transient finite element electromagnetic-circuit coupling model, and calculates the magnetic field at normal and fault situations through the powerful post-processing function of ANSOFT, then magnetic flux density cloud pictures and air-gap magnetic flux density curves of different operating conditions are got. Using MATLAB to analyze and deal with the air-gap flux density cures, we can get the differences of faults in different levels and different positions, which provide a basis for further study of rotor inter-turn short-circuit fault.

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GIORDANO, MAURO, PIERPAOLO DE FEO, PAOLA LUCIDI, EMANUELA dePASCALE, GELSOMINA GIORDANO, LORENA INFANTONE, ANNA MARIA ZOCCOLO, and PIETRO CASTELLINO. "Increased Albumin and Fibrinogen Synthesis in Hemodialysis Patients with Normal Nutritional Status." Journal of the American Society of Nephrology 12, no. 2 (February 2001): 349–54. http://dx.doi.org/10.1681/asn.v122349.

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Abstract. This study compared the rates of whole-body proteolysis and of albumin and fibrinogen synthesis of seven hemodialysis patients (HD) with those of seven normal matched control subjects (C). HD patients had a normal nutritional and inflammatory status and serum albumin levels >3.5 g/dl. Endogenous leucine flux, albumin and fibrinogen fractional synthesis rate (FSR), and absolute intravascular synthesis rate (ASR) of albumin and fibrinogen all were evaluated by a primed/continuous infusion of 5,5,5-D3-L-leucine. Plasma volume was determined by the Evans blue dye dilution method. Endogenous leucine flux was significantly increased in HD (2.64 ± 0.08 μmol/kg per min) compared with C (2.17 ± 0.07 μmol/kg per min,P< 0.05). Serum albumin concentrations were similar in HD and C. Plasma fibrinogen levels were significantly increased in HD compared with C (P< 0.05). Plasma volume was greater in HD than in C (P< 0.05). As a result, total intravascular pool of both albumin (141 ± 7versus114 ± 3 g/1.73 m2,P< 0.05) and fibrinogen (11.7 ± 1versus6.7 ± 0.5 g/1.73 m2,P< 0.05) were greater in HD than in C. Albumin FSR was not statistically different in HD and C. However, albumin ASR was significantly increased in HD than in C (13.7 ± 2versus10.3 ± 1 g/1.73 m2per d,P< 0.05). Similarly, FSR of fibrinogen did not differ in HD and C groups, whereas ASR of fibrinogen was significantly higher in HD than in C (3.31 ± 0.6versus1.94 ± 0.3 g/1.73 m2per d,P< 0.05). In summary, normoalbuminemic HD patients have an increased intravascular pool with a greater absolute synthesis rate of both albumin and fibrinogen and an increased rate of whole-body leucine flux.

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Kong, Beibei, Pasi Ylä-Oijala, and Ari Sihvola. "Electromagnetic Scattering Analysis of SHDB Objects Using Surface Integral Equation Method." Photonics 7, no. 4 (December 18, 2020): 134. http://dx.doi.org/10.3390/photonics7040134.

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A surface integral equation (SIE) method is applied in order to analyze electromagnetic scattering by bounded arbitrarily shaped three-dimensional objects with the SHDB boundary condition. SHDB is a generalization of SH (Soft-and-Hard) and DB boundary conditions (at the DB boundary, the normal components of the D and B flux densities vanish). The SHDB boundary condition is a general linear boundary condition that contains two scalar equations that involve both the tangential and normal components of the electromagnetic fields. The multiplication of these scalar equations with two orthogonal vectors transforms them into a vector form that can be combined with the tangential field integral equations. The resulting equations are discretized and converted to a matrix equation with standard method of moments (MoM). As an example of use of the method, we investigate scattering by an SHDB circular disk and demonstrate that the SHDB boundary allows for an efficient way to control the polarization of the wave that is reflected from the surface. We also discuss perspectives into different levels of materialization and realization of SHDB boundaries.

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Alvarez Alvarez, David Leonardo, Javier Alveiro Rosero Garcia, and Enrique Esteban Mombello. "Core influence on the frequency response analysis (FRA) of power transformers through the finite element method." Ingeniería e Investigación 35, no. 1Sup (November 18, 2015): 110–17. http://dx.doi.org/10.15446/ing.investig.v35n1sup.53771.

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In this paper the influence of core parameters in Frequency Response Analysis is analyzed through the equivalent circuit impedance matrix of the transformer winding; the parameters of the circuit have been computed using the Finite Element Method. In order to appreciate the behavior of the iron core in comparison to the air core, the frequency dependence of resonances is calculated to show how the air core only influences the results at low frequencies. The core is modeled using a complex permeability, and the parameters of conductivity and permeability are varied to show their influence in the resonances, which turned out to be negligible. In order to explain this behavior, the eigenvalues of the inverse impedance matrix are calculated showing that they are similar for different values of conductivity and permeability. Finally, the magnetic flux inside and outside the core and its influence in the frequency response is studied.<br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" />

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Zhao, Yu Feng, and Kun Xiong. "Magnetization and stress in superconducting film under electromagnetic force with viscous flux flow." Modern Physics Letters B 34, no. 26 (June 6, 2020): 2050283. http://dx.doi.org/10.1142/s0217984920502838.

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In this paper, the magnetization and magnetoelastic behaviors of superconducting film in perpendicular external magnetic field with viscous flux flow are studied. The distribution of magnetic flux density, current density, physical strength and normal stress in the film is calculated during the increase of external magnetic field. Among others, the variations in shielding region and mechanical response with viscous magnetic flux flow are analyzed. The results indicate that the magnetization and magnetoelastic behavior in the film with viscous flu flow are different from the quasistatic critical state model, such as the origin Bean model. With the obtained results, since the film is in an external field, we can even predict the maximum probability of cracking. Similarly, it is valuable to derive the theory of magnetostriction of thin films to further popularize the method.

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Yu, Chun-Mei, Dang-Jun Zhao, and Ye Yang. "Efficient Convex Optimization of Reentry Trajectory via the Chebyshev Pseudospectral Method." International Journal of Aerospace Engineering 2019 (May 2, 2019): 1–9. http://dx.doi.org/10.1155/2019/1414279.

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A novel sequential convex (SCvx) optimization scheme via the Chebyshev pseudospectral method is proposed for efficiently solving the hypersonic reentry trajectory optimization problem which is highly constrained by heat flux, dynamic pressure, normal load, and multiple no-fly zones. The Chebyshev-Gauss Legend (CGL) node points are used to transcribe the original dynamic constraint into algebraic equality constraint; therefore, a nonlinear programming (NLP) problem is concave and time-consuming to be solved. The iterative linearization and convexification techniques are proposed to convert the concave constraints into convex constraints; therefore, a sequential convex programming problem can be efficiently solved by convex algorithms. Numerical results and a comparison study reveal that the proposed method is efficient and effective to solve the problem of reentry trajectory optimization with multiple constraints.

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Kotapati, Hari Kiran, and Philip D. Bates. "Normal phase HPLC method for combined separation of both polar and neutral lipid classes with application to lipid metabolic flux." Journal of Chromatography B 1145 (May 2020): 122099. http://dx.doi.org/10.1016/j.jchromb.2020.122099.

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Rodríguez-Navarro, A., W. Otañno-Rivera, J. M. García-Ruiz, R. Messier, and L. J. Pilione. "Preparation of highly oriented polycrystalline AlN thin films deposited on glass at oblique-angle incidence." Journal of Materials Research 12, no. 7 (July 1997): 1689–92. http://dx.doi.org/10.1557/jmr.1997.0232.

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A new method to prepare polycrystalline AlN thin films biaxially oriented on amorphous substrates has been demonstrated. The films were deposited at different angles of incidence with a rf sputtering system. Population-1 crystallites, oriented with their c-axis pointing toward the incoming flux with random orientation in aximuthal directions, predominate at low angle of incidence (near normal). Population-2 crystallites result from non-normal incidence and have their c-axis tilted away from the incoming flux and predominate at high, near glancing, angle of incidence. The alignment of crystallites (population-2) increases with angle of incidence. Crystallites align along the [11*0] channeling direction, characterized by a low sputtering yield, while misoriented crystal grains suffer a higher resputtering and their growth is inhibited. For films deposited at 75°, the FWHM of an x-ray ϕ scan profile is 25°, indicating a high in-plane alignment.

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Qamar, Aamir, Muhammad Umair, Fan Yang, Muhammad Uzair, and Zeeshan Kaleem. "Derivative Method Based Orientation Detection of Substation Grounding Grid." Energies 11, no. 7 (July 18, 2018): 1873. http://dx.doi.org/10.3390/en11071873.

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The grounding grid is a key part of substation protection, which provides safety to personnel and equipment under normal as well as fault conditions. Currently, the topology of a grounding grid is determined by assuming that its orientation is parallel to the plane of earth. However, in practical scenarios, the assumed orientation may not coincide with the actual orientation of the grounding grid. Hence, currently employed methods for topology detection fails to produce the desired results. Therefore, accurate detection of grounding grid orientation is mandatory for measuring its topology accurately. In this paper, we propose a derivative method for orientation detection of grounding grid in high voltage substations. The proposed method is applicable to both equally and unequally spaced grounding grids. Furthermore, our method can also determine the orientation of grounding grid in the challenging case when a diagonal branch is present in the mesh. The proposed method is based on the fact that the distribution of magnetic flux density is perpendicular to the surface of the earth when a current is injected into the grid through a vertical conductor. Taking the third order derivative of the magnetic flux density, the main peak coinciding with the position of underground conductor is accurately obtained. Thus, the main peak describes the orientation of buried conductor of grounding grid. Simulations are performed using Comsol Multiphysics 5.0 to demonstrate the accuracy of the proposed method. Our results demonstrate that the proposed method calculate the orientation of grounding grid with high accuracy. We also investigate the effect of varying critical parameters of our method.

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30

Latifah, Nurul, Sigit Febrianto, Anindya Wirasatriya, Hadi Endrawati, Muhammad Zainuri, Suryanti Suryanti, and Andreas Nur Hidayat. "AIR-SEA FLUX OF CO2 IN THE WATERS OF KARIMUNJAWA ISLAND, INDONESIA." Saintek Perikanan : Indonesian Journal of Fisheries Science and Technology 16, no. 3 (October 23, 2020): 171–78. http://dx.doi.org/10.14710/ijfst.16.3.171-178.

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The purpose of this study was to determine the distribution of CO2 flux in Karimunjawa in the east monsoon. The variables in this study were temperature; pH; salinity; DO; CO2 atm was measured using a CO2 meter; chlorophyll-a, phosphate, silicate were measured spectrophotometric method. Total Alkalinity / TA was measured using the titration method with the principle of changing pH; DIC (Dissolved Inorganic Carbon) was measured using CO2sys software. The partial pressure of seawater carbon dioxide calculated using formula: pCO2sea = 6.31T2 + 61,9 Chla2 – 365.85T – 94.41 Chl-a +5715.94, the partial pressure of atmospheric carbon dioxide calculated using formula: pCO2atm = xCO2atm (pb - pH2O). The calculation of the estimated CO2 flux using the formula: Flux CO2 = Kh x kwa x (∆pCO2) , if the CO2 flux has a positive value water acts as a CO2 source, and if it is negative, the waters act as a CO2 sink.. CO2 flux in Karimunjawa waters during east monsoon (represented by August 2018) showed that in Karimunjawa waters with normal pH 7.2-7.4 were dominated by bicarbonate ion HCO3-with an average value of DIC 1847.24 µmol/kg dan TA 1912.51 µmol/kg. The partial pressure of seawater CO2 is higher than the partial pressure of atmospheric CO2 this indicates that the role of Karimunjawa waters as a source of CO2 where there is release of carbon dioxide into the atmosphere with CO2 flux values ranging from 8.549 – 13.272 mmol m-2 day-1. The variables that affect the flux of CO2 were the pCO2sea and ΔpCO2 with a very strong and positive correlation. These two variables were influenced by sea water temperature, salinity, chlorophyll-a, phosphate and silicate.

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31

Epifanio, C. C. "A Method for Imposing Surface Stress and Heat Flux Conditions in Finite-Difference Models with Steep Terrain." Monthly Weather Review 135, no. 3 (March 1, 2007): 906–17. http://dx.doi.org/10.1175/mwr3297.1.

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Abstract A numerical implementation of the surface stress boundary condition is presented for finite-difference models in which the terrain slope and curvature cannot necessarily be considered small. The method involves reducing the discretized stress condition in terrain-following coordinates to a pair of coupled linear systems for the two horizontal velocity components at the boundary. The linear systems are then solved iteratively at each model time step to provide the unique boundary values of velocity consistent with the specified values of the stress. Similar methods are used to prescribe the normal flux of heat across the boundary. A related method for imposing stress conditions in two-dimensional vorticity–streamfunction models is also discussed. The effectiveness of the boundary conditions is demonstrated through a series of test problems involving topographic wake flows and thermally driven flows on steep slopes. It is shown that the use of the conventional flat-boundary approximation can lead to substantial errors when the resolved topography is sufficiently steep.

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32

Feng, Jing, Tian Di Liu, Yan Chen, Yu Ting Wang, Yue Ming Ren, Yan Zhuo Lv, and Zhuang Jun Fan. "Morphology and Magnetic Properties of NiCuZn Ferrite Synthesized by Solid-Molten Salt Method." Advanced Materials Research 873 (December 2013): 24–29. http://dx.doi.org/10.4028/www.scientific.net/amr.873.24.

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Cu doped NiCuZn ferrite Ni0.4-xCuxZn0.6Fe2O4(x=0.16~0.28) have been prepared by the solid-molten salt method using NaCl as flux. The structure and properties were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) techniques. It is found that addition of Cu2+results in the particles size growing up because of the tend of crystal structure to be a normal Zn ferrite.TheMsvalues of NCZF are decrease gradually with increasing of Cu content. Curie temperature (Tc) increases with Cu2+content in the range of x<0.20, and then decreasing rapidly. This can be ascribed to that the lower magnetization moment Cu2+ion amount of B-site increasing leads to weaker super-exchange effect.

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33

Qi, Jiang. "Experimental Study of Interference Factors and Finite Element Simulation on Oil-Gas Pipeline Magnetic Flux Leakage Density." Advanced Materials Research 26-28 (October 2007): 1255–60. http://dx.doi.org/10.4028/www.scientific.net/amr.26-28.1255.

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Some methods of enhancing oil-gas pipeline magnetic flux leakage (MFL) detection technique are introduced in the paper. Some man-made defects or imperfections on the pipe surface are detected via the axial magnetization inspection vehicle along the pipeline. The magnetic dipole model of corrosion defect is stated and the important interference factors on magnetic flux leakage are analyzed. Finite element method is used to analyze and simulate normal defects on pipe surface, which can attribute to get natural defect MFL signal. The influence of benign pipeline artifacts (valves, welds, tees, flanges, etc.), pipe material and pipe wall, vehicle velocity, defect dimensions and interaction among defects, and so on are studied in detail. The magnetic flux leakage contour images or indication extraction maps are given and presented. These interference factors are compensated and solved. These approaches and results applied in the paper are contributed to the feature extraction and indication of pipeline abnormality. The results suggest that these approaches and conclusions are significantly effective for the pipeline magnetic flux leakage inspection.

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Dutta, Swagata, Nam Kyeun Kim, Raj Das, and Debes Bhattacharyya. "Evaluating Orientation Effects on the Fire Reaction Properties of Flax-Polypropylene Composites." Polymers 13, no. 16 (August 4, 2021): 2586. http://dx.doi.org/10.3390/polym13162586.

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In this work, the fire reaction properties of flax-polypropylene (PP) composites were investigated at multiple sample angles both experimentally and numerically under two different heat flux conditions (35 and 50 kW/m2) in the cone calorimeter environment. An innovative testing setup which can accommodate a wide range of angles between 0° and 90° for the sample angle frame was developed to perform cone calorimeter tests at different sample angles. An advanced numerical predictive model based on the finite volume method was developed using the fire dynamics simulator (FDS) to quantify the dependency of ignition and combustion properties with sample angles. The numerical model was validated against experimental data from the cone calorimeter tests. The experimental and numerical analyses were conducted to quantify the effects of sample orientation on the different fire reaction properties i.e., ignition time, ignition temperature, burn time, heat release rate (HRR), critical heat flux, etc. The numerical method was utilised to analyse the mechanisms controlling the effect of heat convection and radiation blockage on the heating process. The study establishes that the sample orientation (with respect to the heat flux normal) has a significant influence on the fire reaction properties of natural fibre composites.

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35

Sidorov, Vladimir P. "Calculation of Modes of Arc Welding under the Flux of Double-Sided Butt Joints." Materials Science Forum 946 (February 2019): 889–94. http://dx.doi.org/10.4028/www.scientific.net/msf.946.889.

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This paper gives the analysis of energy costs for arc automatic welding under the flux of double-sided butt joint without edge preparation according to the thickness of welding sheets. The coefficients for a linear dependence of specific energy from plate thickness are obtained. From this, a calculation method of effective power, current and arc voltage is proposed according to the joint formation speed. To calculate a fusion area of a weld section, a model of a surficial normal-circular heat source with an average heat flow in a heating spot 14−16 kW/cm2is used. Acceptable convergence of target and experimental cross-section areas of a weld is achieved for an arc reverse polarity. Calculation method let take into account the influence of arc polarity on a fusion area of a base metal. Main efficiency factors of a double-sided welding are defined. Possible reasons of augmentation of fusion effectiveness of a base metal in comparison with the electrode metal are noted.

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36

Gangadhar, K., Chintalapudi Suresh Kumar, S. Mohammed Ibrahim, and Giulio Lorenzini. "Effect of Viscous Dissipation on Upper - Convected Maxwell Fluid with Cattaneo-Christov Heat Flux Model Using Spectral Relaxation Method." Defect and Diffusion Forum 388 (October 2018): 146–57. http://dx.doi.org/10.4028/www.scientific.net/ddf.388.146.

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The study observes the flow and heat transfer in upper-convected Maxwell fluid over a rapidly stretching surface with viscous dissipation. Cattaneo-Christov heat flux model has been used in the preparation of the energy equation. The model is used in guessing the impacts of thermal relaxation time over boundary layer. Similarity method has been used to keep normal the supervising boundary layer equations. Local similarity solutions have been obtained through spectral relaxation method. The fluid temperature has a relation with thermal relaxation time inversely and our calculations have shown the same.. In addition the fluid velocity is a receding activity of the fluid relaxation time. A comparative study of Fourier’s law and the Cattaneo-Christov’s law has been done and inserted in this.

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37

Jones, John G., Michael A. Solomon, A. Dean Sherry, F. M. H. Jeffrey, and Craig R. Malloy. "13C NMR measurements of human gluconeogenic fluxes after ingestion of [U-13C]propionate, phenylacetate, and acetaminophen." American Journal of Physiology-Endocrinology and Metabolism 275, no. 5 (November 1, 1998): E843—E852. http://dx.doi.org/10.1152/ajpendo.1998.275.5.e843.

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Anaplerotic, pyruvate recycling, and gluconeogenic fluxes were measured by13C isotopomer analysis of plasma glucose, urinary phenylacetylglutamine, and urinary glucuronide in normal, 24-h-fasted individuals after ingestion of [U-13C]propionate, phenylacetate, and acetaminophen. Plasma glucose isotopomer analysis reported a total anaplerotic flux of 5.92 ± 1.03 (SD) relative to citrate synthase. This was not significantly different from glucuronide and phenylacetylglutamine analyses (6.08 ± 1.16 and 7.14 ± 1.94, respectively). Estimates of pyruvate recycling from glucose and glucuronide isotopomer distributions were almost identical (3.55 ± 0.99 and 3.66 ± 1.11, respectively), whereas phenylacetylglutamine reported a significantly higher estimate (5.74 ± 2.13). As a consequence, net gluconeogenic flux reported by phenylacetylglutamine (1.41 ± 0.28) was significantly less than that reported by glucose (2.37 ± 0.64) and glucuronide (2.42 ± 0.76). This difference in fluxes detected by analysis of phenylacetylglutamine vs. hexose is likely due to compartmentation of hepatic metabolism of propionate. Net gluconeogenic flux estimates made by use of this stable isotope method are in good agreement with recent measurements in humans with [14C]propionate.

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38

Nanda, Piyush, and Amit Ghosh. "Genome Scale-Differential Flux Analysis reveals deregulation of lung cell metabolism on SARS-CoV-2 infection." PLOS Computational Biology 17, no. 4 (April 9, 2021): e1008860. http://dx.doi.org/10.1371/journal.pcbi.1008860.

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The COVID-19 pandemic is posing an unprecedented threat to the whole world. In this regard, it is absolutely imperative to understand the mechanism of metabolic reprogramming of host human cells by SARS-CoV-2. A better understanding of the metabolic alterations would aid in design of better therapeutics to deal with COVID-19 pandemic. We developed an integrated genome-scale metabolic model of normal human bronchial epithelial cells (NHBE) infected with SARS-CoV-2 using gene-expression and macromolecular make-up of the virus. The reconstructed model predicts growth rates of the virus in high agreement with the experimental measured values. Furthermore, we report a method for conducting genome-scale differential flux analysis (GS-DFA) in context-specific metabolic models. We apply the method to the context-specific model and identify severely affected metabolic modules predominantly comprising of lipid metabolism. We conduct an integrated analysis of the flux-altered reactions, host-virus protein-protein interaction network and phospho-proteomics data to understand the mechanism of flux alteration in host cells. We show that several enzymes driving the altered reactions inferred by our method to be directly interacting with viral proteins and also undergoing differential phosphorylation under diseased state. In case of SARS-CoV-2 infection, lipid metabolism particularly fatty acid oxidation, cholesterol biosynthesis and beta-oxidation cycle along with arachidonic acid metabolism are predicted to be most affected which confirms with clinical metabolomics studies. GS-DFA can be applied to existing repertoire of high-throughput proteomic or transcriptomic data in diseased condition to understand metabolic deregulation at the level of flux.

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39

Brahm, J., and W. R. Galey. "Diffusional solute flux during osmotic water flow across the human red cell membrane." Journal of General Physiology 89, no. 5 (May 1, 1987): 703–16. http://dx.doi.org/10.1085/jgp.89.5.703.

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The effect of solvent drag on the unidirectional efflux of labeled water, urea, and chloride from human red cells was studied by means of the continuous flow tube method under conditions of osmotic equilibrium and net volume flow. Solvent (water) flow out of cells was created by mixing cells equilibrated in 100 mM salt solution with a 200-mM or 250-mM salt solution, while flow of water into cells was obtained by equilibrating the cells in the higher concentration and mixing them with the 100-mM solution. Control experiments constitute measurements of efflux of [14C]ethanol in normal cells and 3H2O in cells treated with p-chloromercuribenzosulfonate under the conditions described above. In both instances, the solute is known to penetrate the membrane through nonporous pathways. As anticipated, the tracer flux of neither urea nor chloride showed any dependence on net solvent flow, regardless of the direction. If one assumes the recently reported reflection coefficient for urea of 0.7, the urea tracer flux should change by at least 24% under volume flow conditions. Since such changes would be easily detected with our method, we conclude that the pathways for water, for urea, and for chloride are functionally separated.

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40

Bens, Marcelle, Jean-Paul Duong Van Huyen, Françoise Cluzeaud, Jacques Teulon, and Alain Vandewalle. "CFTR disruption impairs cAMP-dependent Cl−secretion in primary cultures of mouse cortical collecting ducts." American Journal of Physiology-Renal Physiology 281, no. 3 (September 1, 2001): F434—F442. http://dx.doi.org/10.1152/ajprenal.2001.281.3.f434.

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The role of the cystic fibrosis transmembrane conductance regulator (CFTR) in the renal cortical collecting duct (CCD) has not yet been fully elucidated. Here, we investigated the effects of deamino-8-d-arginine vasopressin (dDAVP) and isoproterenol (ISO) on NaCl transport in primary cultured CCDs microdissected from normal [CFTR(+/+)] and CFTR-knockout [CFTR(−/−)] mice. dDAVP stimulated the benzamyl amiloride (BAm)-sensitive transport of Na+ assessed by the short-circuit current ( I sc) method in both CFTR(+/+) and CFTR(−/−) CCDs to a very similar degree. Apical addition of 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB) or glibenclamide partially inhibited the rise in I sc induced by dDAVP and ISO in BAm-treated CFTR(+/+) CCDs, whereas dDAVP, ISO, and NPPB did not alter I sc in BAm-treated CFTR(−/−) CCDs. dDAVP stimulated the apical-to-basal flux and, to a lesser extent, the basal-to-apical flux of 36Cl− in CFTR(+/+) CCDs. dDAVP also increased the apical-to-basal36Cl− flux in CFTR(−/−) CCDs but not the basal-to-apical 36Cl− flux. These results demonstrate that CFTR mediates the cAMP-stimulated component of secreted Cl− in mouse CCD.

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41

Ahmad, M. Z., E. Sulaiman, S. K. Rahimi, G. M. Romalan, and M. Jenal. "Analysis of Permanent Magnet Demagnetization Effect Outer-rotor Hybrid Excitation Flux Switching Motor." International Journal of Power Electronics and Drive Systems (IJPEDS) 8, no. 1 (March 1, 2017): 255. http://dx.doi.org/10.11591/ijpeds.v8.i1.pp255-261.

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This paper addresses the irreversible permanent magnet (PM) demagnetization analysis of hybrid excitation flux switching motor (HEFSM) with outer-rotor configuration. PM demagnetization cause the PM strength used in the motor significantly reduces and hence contributes less torque performance. The study is focused on thermal analysis and conducted at various temperature up to as high as 180 degrees Celsius which has a tendency to be demagnetized. Therefore, PM demagnetization is among a critical issue and influences the choice of the applied motor. The analysis is carried out based on finite element method (FEM) and percentage of PM demagnetization is then calculated. Finally, based on simulated and calculated results the final design outer-rotor HEFSM has only 0.85 percent PM demagnetization at very high temperature and obviously the is no PM demagnetization at normal operating conditions.

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42

Kuang, Yangyu, Kailiang Wu, and Huazhong Tang. "Runge-Kutta Discontinuous Local Evolution Galerkin Methods for the Shallow Water Equations on the Cubed-Sphere Grid." Numerical Mathematics: Theory, Methods and Applications 10, no. 2 (May 2017): 373–419. http://dx.doi.org/10.4208/nmtma.2017.s09.

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AbstractThe paper develops high order accurate Runge-Kutta discontinuous local evolution Galerkin (RKDLEG) methods on the cubed-sphere grid for the shallow water equations (SWEs). Instead of using the dimensional splitting method or solving one-dimensional Riemann problem in the direction normal to the cell interface, the RKDLEG methods are built on genuinely multi-dimensional approximate local evolution operator of the locally linearized SWEs on a sphere by considering all bicharacteristic directions. Several numerical experiments are conducted to demonstrate the accuracy and performance of our RKDLEG methods, in comparison to the Runge-Kutta discontinuous Galerkin method with Godunov's flux etc.

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43

Kumar, Arvind, and Ram Naresh Rai. "Evaluation of Wear Properties of Stir Cast AA7050 -10% B₄C Ex Situ Composite through Fuzzy-TOPSIS MCDM Method." Solid State Phenomena 291 (May 2019): 1–12. http://dx.doi.org/10.4028/www.scientific.net/ssp.291.1.

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The present paper discussed the dry sliding wear and friction behavior of flux assisted stir cast AA7050-10% B4C composite. The K2TiF6 flux improves the wettability of B4C in molten aluminium. The casted composite were heat treated as per T-6 standard. The microstructure studies confirm the uniform distribution of B4C with the layers of Ti compound around it. Both As Casted Composite hereafter called as ACC and Heat Treated Composite hereafter called as HTC under gone dry sliding wear test at room temperature. The experiments were designed using Taguchi L18 mixed design. The responses of the experiment were optimized using fuzzy-TOPSIS MCDM method. From the experimental investigation it was concluded that wear rate of the composite material is a function of normal loads and sliding speed. Moreover, wear rate, coefficient of friction and amount of heat generation for HTC is comparatively less than ACC. This may due to the homogeneous distribution of particles and also formation proper interfacial bond between matrix and reinforcements after heat treatment.

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44

Fairs, S. L. E., R. O. Ham, B. A. Conway, and V. C. Roberts. "Limb perfusion in the lower limb amputee—a comparative study using a laser Doppler flowmeter and a transcutaneous oxygen electrode." Prosthetics and Orthotics International 11, no. 2 (August 1987): 80–84. http://dx.doi.org/10.3109/03093648709078183.

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Accurate and objective assessment of amputation level in the lower limb plays an important role in patient management. Laser Doppler flowmetry (LDF) is a new and noninvasive technique for skin blood flow measurement and has been used pre-operatively in 25 patients undergoing amputation for vascular disease and in five normal controls. Baseline flux measurements were made at room temperature on the medial aspect of legs and then again after local heating of the skin for five minutes. Transcutaneous oxygen measurements were made at the same site for comparison and amputation level in patients selected on this basis. Significant differences (p<0.001) in TcPO2 values were found between controls (10.9±0.5kPa), below-knee (BK) amputees (6.0±1.5kPa) and above-knee (AK) amputees (1.5±0.6kPa). Baseline LDF flux did not differ significantly between any group. Heated flux values did however show a significant difference (p<0.005) between controls (52.4±23.5) and both BK (20.6±9.2) and AK groups (8.1±7.7) and also between the amputee groups. The relative increase in flux (heated flux/baseline flux) differed significantly between the BK (3.3±1.5) and AK (1.2±0.3) groups (p<0.001) and between these two and the controls (11.2±5.4) (p<0.001). The correlation between relative increase in flux and TcPO2 was 0.7 (p<0.001). It is concluded that laser Doppler flowmetry used in conjunction with thermal stressing could provide a quick, simple and non-invasive method for objectively determining amputation level in the lower limb.

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45

Li, Bo, and John Shopple. "An Interface-Fitted Finite Element Level Set Method with Application to Solidification and Solvation." Communications in Computational Physics 10, no. 1 (July 2011): 32–56. http://dx.doi.org/10.4208/cicp.230510.240910a.

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AbstractA new finite element level set method is developed to simulate the interface motion. The normal velocity of the moving interface can depend on both the local geometry, such as the curvature, and the external force such as that due to the flux from both sides of the interface of a material whose concentration is governed by a diffusion equation. The key idea of the method is to use an interface-fitted finite element mesh. Such an approximation of the interface allows an accurate calculation of the solution to the diffusion equation. The interface-fitted mesh is constructed from a base mesh, a uniform finite element mesh, at each time step to explicitly locate the interface and separate regions defined by the interface. Several new level set techniques are developed in the framework of finite element methods. These include a simple finite element method for approximating the curvature, a new method for the extension of normal velocity, and a finite element least-squares method for the reinitialization of level set functions. Application of the method to the classical solidification problem captures the dendrites. The method is also applied to the molecular solvation to determine optimal solute-solvent interfaces of solvation systems.

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46

Augason, G. C., J. A. Brown, and D. R. Alexander. "Comparison of Blanketing in a 3000 K, Oxygen Rich, Spherically Symmetric Model with the Blanketing in Non-Mira, M Giant Stars." International Astronomical Union Colloquium 106 (1989): 157. http://dx.doi.org/10.1017/s0252921100062874.

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A flux curve has been computed using a preliminary, spherically symmetric model for a 3000 K, oxygen rich, giant star. The model was computed using the opacity sampling method with an improved frequency set, improved molecular equilibrium data and an improved set of opacities. In addition, a continuum flux curve is computed using the same model and only continuum opacity sources. The relative and to some extent the absolute blanketing used to compute both the model and the flux curve derived from the model may be illustrated by dividing the normal flux curve by the continuum flux curve. This same procedure is used to illustrate the blanketing in an observed star by dividing the observed flux curve by the continuum flux curve. When this is done, the blanketing in an observed flux curve may be compared with the blanketing in a model. When this comparison is made, it is obvious that the treatment of blanketing in the “new” flux curve, computed using the spherically symmetric model and using new parameters, is superior to the flux curves based on earlier models. This is especially true in the regions of the fundamental, the first overtone and the second overtone of Co. Also, the new water vapor opacity is much improved. The new water vapor opacity is based on actual measurements of high temperature water vapor. Correct representation of water vapor opacity is extremely important for oxygen rich stars because it forms a psuedo continuum because of its many lines. The TiO opacity does not fit the observations well. When the spherically symmetrical model flux curve is compared directly to an observed flux curve, the new flux curve gives a better fit than do flux curves computed from previous models. There is still (at least for the non-Mira stars) a serious flux excess in the model flux curves at 1.6 microns in the region of the H minus b-f and f-f crossover. However, this excess is not as great for the spherically symmetric model as it is for earlier plane parallel models. It is not determined if this improvement is due to spherical symmetry or due to the new model parameters.

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47

Zhang, Wen-Qing, Jie Li, Kun Zhang, and Peng Cui. "Stability and Bifurcation in Magnetic Flux Feedback Maglev Control System." Mathematical Problems in Engineering 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/537359.

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Nonlinear properties of magnetic flux feedback control system have been investigated mainly in this paper. We analyzed the influence of magnetic flux feedback control system on control property by time delay and interfering signal of acceleration. First of all, we have established maglev nonlinear model based on magnetic flux feedback and then discussed hopf bifurcation’s condition caused by the acceleration’s time delay. The critical value of delayed time is obtained. It is proved that the period solution exists in maglev control system and the stable condition has been got. We obtained the characteristic values by employing center manifold reduction theory and normal form method, which represent separately the direction of hopf bifurcation, the stability of the period solution, and the period of the period motion. Subsequently, we discussed the influence maglev system on stability of by acceleration’s interfering signal and obtained the stable domain of interfering signal. Some experiments have been done on CMS04 maglev vehicle of National University of Defense Technology (NUDT) in Tangshan city. The results of experiments demonstrate that viewpoints of this paper are correct and scientific. When time lag reaches the critical value, maglev system will produce a supercritical hopf bifurcation which may cause unstable period motion.

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48

Nascimento, Diego Carvalho do, Pedro Luiz Ramos, David Elal-Olivero, Milton Cortes-Araya, and Francisco Louzada. "Generalizing Normality: Different Estimation Methods for Skewed Information." Symmetry 13, no. 6 (June 15, 2021): 1067. http://dx.doi.org/10.3390/sym13061067.

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Normality is the most commonly used mathematical supposition in data modeling. Nonetheless, even based on the law of large numbers (LLN), normality is a strong presumption, given that the presence of asymmetry and multi-modality in real-world problems is expected. Thus, a flexible modification in the normal distribution proposed by Elal-Olivero adds a skewness parameter called Alpha-skew-normal (ASN) distribution, which enables bimodality and fat-tail, if needed, although it is sometimes not trivial to estimate this third parameter (regardless of the location and scale). This work analyzed seven different statistical inferential methods towards the ASN distribution on synthetic data and historical data of water flux from 21 rivers (channels) in the Atacama region. Moreover, the contributions of this paper are related to the estimations of probability surrounding rivers’ flux levels in the surroundings of Copiapó city, which is the most economically important city of the third Chilean region and is known to be located in one of the driest areas on Earth (excluding the North and the South Poles). The results show the competitiveness of the MPS and RADE methods with respect to the MLE method, as well as their excellent performance.

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Keenan, Seth, Yana Nec, and Greg Huculak. "Landfill Gas Flow — Effects of Asymmetry." Journal of Solid Waste Technology and Management 47, no. 1 (February 1, 2021): 188–203. http://dx.doi.org/10.5276/jswtm/2021.188.

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Waste disposal is the responsibility of cities throughout the world. The most common method in North America is to bury waste in landfills. Landfill operators comply with regulations to control hazardous emissions known as landfill gas (LFG). The gas is extracted via horizontal or vertical wells and removed from the site. This study examines arrays of horizontal wells placed side by side or stacked, and resultant landfill gas flux between adjacent cells. A landfill's lifetime often sees changes in the number, relative location and efficacy of wells. The ability to predict the response of an array of wells to variation in a single well's fu nctionality is an essential aspect of landfill design and operation. The integrated normal flux between cells is identified as a salient quantity required to construct such prediction models. Numerical solution of flow equations reveals a stunningly simple dependence of the flux on the relative suction strength of proximate cells in a wide range of operational conditions. The flux is one of scarcely few parameters accessible in the field with relative ease and certainty, and thus traceable over time. This property makes the proposed models easy to construct, implement and adjust in practice in custom configurations.

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50

Idiri, Z., F. Redjem, and N. Beloudah. "Analysis of sewage sludge using an experimental prompt gamma neutron activation analysis (pgnaa) set-up with an am-be source." International Journal of Modern Physics: Conference Series 44 (January 2016): 1660215. http://dx.doi.org/10.1142/s2010194516602155.

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An experimental PGNAA set-up using a 1 Ci Am–Be source has been developed and used for analysis of bulk sewage sludge samples issued from a wastewater treatment plant situated in an industrial area of Algiers. The sample dimensions were optimized using thermal neutron flux calculations carried out with the MCNP5 Monte Carlo Code. A methodology is then proposed to perform quantitative analysis using the absolute method. For this, average thermal neutron flux inside the sludge samples is deduced using average thermal neutron flux in reference water samples and thermal flux measurements with the aid of a 3He neutron detector. The average absolute gamma detection efficiency is determined using the prompt gammas emitted by chlorine dissolved in a water sample. The gamma detection efficiency is normalized for sludge samples using gamma attenuation factors calculated with the MCNP5 code for water and sludge. Wet and dehydrated sludge samples were analyzed. Nutritive elements (Ca, N, P, K) and heavy metals elements like Cr and Mn were determined. For some elements, the PGNAA values were compared to those obtained using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma (ICP) methods. Good agreement is observed between the different values. Heavy element concentrations are very high compared to normal values; this is related to the fact that the wastewater treatment plant is treating not only domestic but also industrial wastewater that is probably rejected by industries without removal of pollutant elements. The detection limits for almost all elements of interest are sufficiently low for the method to be well suited for such analysis.

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Journal articles on the topic 'Normal Flux Method (NFM)'

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