scholarly journals Mathematical model of a fluxgate magnetometer

2018 ◽  
Vol 158 ◽  
pp. 01006 ◽  
Author(s):  
Pavel F. Baranov ◽  
Vitalia E. Baranova ◽  
Tamara G. Nesterenko
Keyword(s):  
Mathematical Model ◽  
Polynomial Approximation ◽  
Magnetization Curve ◽  
Electromotive Force ◽  
Signal Frequency ◽  
Fluxgate Magnetometer ◽  
Frequency Content ◽  
The Core ◽  
Measuring Coil ◽  
The Mean

In paper analytical equations for calculate the electromotive force in the measuring coil of the fluxgate magnetometer independent of the drive signal frequency content are presented. Also, the equations for es-timation of the fluxgate sensitivity at any harmonic and for study fluxgates operation with a glance to the waveform and the polynomial approximation of the mean magnetization curve of the core are provided.

Evaluation of Road Utilisation as Space For Holding Social Ceremonies in Indigenous Residential Area of Ogbomoso, Nigeria

2018 ◽  
Vol 1 (March 2018) ◽  
Author(s):  
S.A Okanlawon ◽  
O.O Odunjo ◽  
S.A Olaniyan
Keyword(s):  
Transport Infrastructure ◽  
Noisy Environment ◽  
Policy Makers ◽  
The Core ◽  
Local Roads ◽  
Strict Enforcement ◽  
The Mean ◽  
The One ◽  
The City ◽  
The Town

This study examined Residents’ evaluation of turning transport infrastructure (road) to spaces for holding social ceremonies in the indigenous residential zone of Ogbomoso, Oyo State, Nigeria. Upon stratifying the city into the three identifiable zones, the core, otherwise known as the indigenous residential zone was isolated for study. Of the twenty (20) political wards in the two local government areas of the town, fifteen (15) wards that were located in the indigenous zone constituted the study area. Respondents were selected along one out of every three (33.3%) of the Trunk — C (local) roads being the one mostly used for the purpose in the study area. The respondents were the residents, commercial motorists, commercial motorcyclists, and celebrants. Six hundred and forty-two (642) copies of questionnaire were administered and harvested on the spot. The Mean Analysis generated from the respondents’ rating of twelve perceived hazards listed in the questionnaire were then used to determine respondents’ most highly rated perceived consequences of the practice. These were noisy environment, Blockage of drainage by waste, and Endangering the life of the sick on the way to hospital; the most highly rated reasons why the practice came into being; and level of acceptability of the practice which was found to be very unacceptable in the study area. Policy makers should therefore focus their attention on strict enforcement of the law prohibiting the practice in order to ensure more cordial relationship among the citizenry, seeing citizens’ unacceptability of the practice in the study area.

Batch Crystallization with Crystals Attrition

1993 ◽  
Vol 58 (8) ◽  
pp. 1855-1860 ◽  
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Mathematical Model ◽  
Calcium Sulfate ◽  
Crystal Size ◽  
Theoretical Description ◽  
Secondary Nucleation ◽  
Batch Crystallization ◽  
Batch Time ◽  
The Mean

The dependence of the mean crystal size of the products from batch crystallizers on the batch time occasionally exhibits a maximum, which can be explained by secondary nucleation due to the attrition of crystals. A kinetic equatation of nucleation, comprising a term for crystal attrition, can be used for the theoretical description of such behaviour. A mathematical model of a batch crystallizer with crystal attrition has been verified on the calcium sulfate precipitation.

Validation of New Mathematical Model of Flank Wear by Different Methods

2012 ◽  
Vol 729 ◽  
pp. 169-174 ◽  
Author(s):  
Zoltán Pálmai ◽  
Márton Takács ◽  
Balázs Zsolt Farkas
Keyword(s):  
Activation Energy ◽  
Mathematical Model ◽  
Flank Wear ◽  
Technological Parameters ◽  
Wear Process ◽  
Oxidation Processes ◽  
Industrial Manufacturing ◽  
Thermally Activated ◽  
Optical Electron ◽  
The Mean

Having reviewed the literature on cutting and based on the optical, electron-optical and morphological examinations of wear processes we have reached the conclusion that it is possible to describe the abrasive, adhesive and thermally activated diffusion, oxidation processes in a single mathematical model. The model is a non-linear autonomous differential equation, which can be solved by simple numerical methods. The complex wear equation was validated by the results of the cutting tests performed with P20 carbide on C45 carbon steel. If we have this data, we can calculate the activation energy of the process determining the nature of the wear process. The apparent activation energy of wear is Q=151,7kJ/mol. The model can even be used with changing technological parameters, and the data necessary for the constants of the wear equation may as well be determined even by measurements performed on the tool during industrial manufacturing. By the mean of this data, we can calculate the activation energy determining the nature of the wear process.

Non-invasive determination of the systolic peak-to-peak gradient in children with aortic stenosis: validation of a mathematical model

2000 ◽  
Vol 10 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Valter C. Lima ◽  
Evan Zahn ◽  
Christine Houde ◽  
Jeffrey Smallhorn ◽  
Robert M. Freedom ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Pulse Pressure ◽  
Linear Regression Analysis ◽  
Systolic Pressure ◽  
Pressure Gradients ◽  
Non Invasive ◽  
The Mean ◽  
Congenital Aortic Valvar Stenosis ◽  
Peak Gradient

AbstractDoppler derived systolic pressure gradients have become widely applied as noninvasively obtained estimates of the severity of aortic valvar stenosis. There is little correlation, however, between the Doppler derived peak instantaneous gradient and the peak-to-peak gradient obtained at catheterisation, the latter being the most applied variable to determine severity in children. The purpose of this study was to validate a mathematical model based on data from catheterisation which estimates the peak-to-peak gradient from variables which can be obtained by noninvasive means (Doppler derived mean gradient and pulse pressure), according to the formula: peak-to-peak systolic gradient=6.02+1.49*(mean gradient)−0.44*(pulse pressure). Simultaneous cardiac catheterization and Doppler studies were performed on 10 patients with congenital aortic valvar stenosis. Correlations between the gradients measured at catheter measured, and those derived by Doppler, were performed using linear regression analysis. The mean gradients correlated well (y=0.67 × + 11.11, r=0.87, SEE=6 mm Hg, p=0.001). The gradients predicted by the formula also correlated well with the peak-to-peak gradients measured at catheter (y=0.66 × + 14.44, r=0.84, SEE=9 mm Hg, p=O.002). The data support the application of the model, allowing noninvasive prediction of the peak-to-peak gradient across the aortic valvar stenosis.

The density variation of the earth's central core*

1942 ◽  
Vol 32 (1) ◽  
pp. 19-29
Author(s):  
K. E. Bullen
Keyword(s):  
Pure Iron ◽  
Outer Boundary ◽  
Density Variation ◽  
Central Core ◽  
Good Precision ◽  
Wide Margin ◽  
The Core ◽  
The Earth ◽  
The Mean ◽  
Published Paper

ABSTRACT A detailed analysis of the problem of the earth's density variation has been extended to the earth's central core. It is shown that in the region between the outer boundary of the core and a distance of about 1400 km. from the earth's center the density ranges from 9.4 gm/cm.3 to 11.5 gm/cm.3 within an uncertainty which, if certain general assumptions are true, does not exceed 3 per cent. The density and pressure figures are, moreover, compatible with the existence of fairly pure iron in this part of the earth. The result for the earth's outer mantle as given in a previously published paper, together with those in the present paper, are found to give with good precision the density distribution in a region occupying 99 per cent of the earth's volume. Values of the density within 1400 km. of the earth's center are subject, however, to a wide margin of uncertainty, and there appears to be no means of resolving this uncertainty for the present. The most that can be said is that the mean density in the latter region is greater than 12.3 gm/cm.3 and may quite possibly be several gm/cm.3 in excess of this figure. In the present paper figures are also included for the variation of gravity and the distribution of pressure within the central core. The gravity results are shown to be subject to an appreciable uncertainty except within about 1000 km. of the outer boundary of the core, but the pressure results are expected to be closely accurate at all depths.

Early Clinical Outcomes of the Active Seal Technology of the AFX Endovascular Aortic Aneurysm System With the VELA Cuff for Patients With a Conical Proximal Neck

2022 ◽  
pp. 152660282110709
Author(s):  
Naoki Fujimura ◽  
Hideaki Obara ◽  
Takaaki Nagano ◽  
Yukihisa Ogawa ◽  
Taira Kobayashi ◽  
...  
Keyword(s):  
Aortic Aneurysm ◽  
Endovascular Aneurysm Repair ◽  
Aortic Aneurysms ◽  
Proximal Neck ◽  
Landing Zone ◽  
The Core ◽  
The Mean ◽  
Instructions For Use ◽  
Lost To Follow Up

Purpose: To evaluate the efficacy of the Active Seal technology employed in the AFX endovascular aortic aneurysm system (AFX), during endovascular aneurysm repair (EVAR) in patients with abdominal aortic aneurysms (AAAs) having a conical proximal neck. Materials and Methods: A retrospective analysis of the EVAR for AAA with a conical proximal neck using the AFX was performed at 17 Japanese hospitals between January 2016 and August 2020. The conical proximal neck was defined as a cone-shaped proximal neck, with more than 10% diameter increase within a 15 mm length at the proximal landing zone. All anatomical analyses were performed in the core laboratory, and cases with parallel walls within the proximal neck adequate for the landing zone were excluded from the study. Results: This study included 53 patients, but only 39 patients (mean age, 76.6 ± 6.7 years; 87.0% males; mean aneurysm diameter, 52.0 ± 8.0 mm) were analyzed after being characterized as having a pure conical neck by the core laboratory. The mean proximal neck diameters at the lower renal artery and proximal edge of the aneurysm were 20.0 ± 2.9 mm and 27.5 ± 4.9 mm, respectively. The mean proximal neck length was 21.5 ± 6.0 mm. Instructions for use violations other than the conical neck were observed in 15 patients (38.5%). The VELA cuff was used in all cases; however, additional proximal cuff was required in 9 more cases (23.1%). The Active Seal technology was able to significantly extend the proximal sealing zone from 21.5 ± 6.0 to 26.0 ± 12.2 mm ( p = .047). Thirty-six patients completed the 12-month follow-up (one patient was lost to follow-up, and 2 patients died from causes unrelated to the aneurysm), and there were no type-1a and 3 endoleaks with only one reintervention (2.6%) related to type 1b endoleak in the 12-month period. Furthermore, there was no significant enlargement of the proximal neck diameter at 12 months (at 1 month: 20.6 ± 3.4 mm and at 12 months: 21.3 ± 3.8 mm; p = .420). Conclusion: The Active Seal technology of the AFX significantly extended the proximal seal zone and no type-1a endoleak and proximal neck dilation was observed in patients with conical proximal neck at 12 months.

scholarly journals Effect of Core Training Program on Physical Functional Performance in Female Soccer Players

2016 ◽  
Vol 9 (5) ◽  
pp. 115 ◽  
Author(s):  
Cengiz Taskin
Keyword(s):  
Functional Performance ◽  
Vertical Jump ◽  
Training Group ◽  
Soccer Players ◽  
Control Group ◽  
The Core ◽  
Standing Long Jump ◽  
Long Jump ◽  
The Mean ◽  
Core Training

<p class="apa">The purpose of this study was to determine the effect of core training program on speed, acceleration, vertical jump, and standing long jump in female soccer players. A total of 40 female soccer players volunteered to participate in this study. They were divided randomly into 1 of 2 groups: core training group (CTG; n = 20) and control group (CG; n = 20). The mean (SD) age was 19.05 ± 1.15 years, height was 160.60 ± 4.22 cm, weight was 56.45 ± 3.33 kg, and sport age was 4.50 ± 1.24 for the core training group; the mean (SD) age was 18.55 ± 0.76 years, height was 159.10 ± 3.86 cm, weight was 52.20 ± 3.60 kg, and sport age was 3.35 ± 0.75 years for the control group. Following randomization, the 2 groups did not differ significantly (p&gt;0.05) in any of the dependent variables. The subjects in the control group did not participate in the training and participated only in the pre- and posttest measurements. To evaluate the effect of core training over the functional performance, we applied a testing procedure that included measurements of speed, acceleration, vertical jump, and standing long jump. The core training group showed a 3.4%, 5.9%, 13.3%, 4.2% improvement in speed, acceleration, vertical jump, and standing long jump (respectively) (P&lt;0.05), whereas the control group did not change (P&gt;0.05). In conclusion, Core exercises were improved speed, acceleration, vertical jump, and standing long jump in 18-19 years-old female soccer players. Therefore, it is believed core training is necessary for optimal sport performance and should not be dismissed for all sport branches.</p>

A Rotor Flux Observer Based on Nonlinear Quadrature Double Compensation

2011 ◽  
Vol 128-129 ◽  
pp. 25-29
Author(s):  
Bo Fan ◽  
Xing Li ◽  
Jie Xin Pu ◽  
Jian Wei Ma ◽  
Ju Wei Zhang
Keyword(s):  
Induction Motor ◽  
Electromotive Force ◽  
Signal Frequency ◽  
Quick Response ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Flux Observer ◽  
Low Pass ◽  
Rotor Flux ◽  
Order Change

In order to solve the problem of integration saturation drift and hardship in compensation quantity calculation exist in rotor flux observation of induction motor, a rotor flux observer based on nonlinear quadrature double compensation method is presented in this paper. The quantity of compensation is determined dynamically according to the quadrature level between flux and back electromotive force. Through the order change of compensation and low-pass filter, quick response of flux when signal frequency leaps is realized. The simulation result shows that the method can improve the flux waveform, realize the accurate and swift track of flux.

scholarly journals Enhancing Quality Assurance through Harmonization of Business Education Curricular in Nigerian Universities and Avoiding Functional Dilemmas of Expectations and Realities

2014 ◽  
Vol 5 (3) ◽  
pp. 101-107
Author(s):  
Amahi Fidelis U
Keyword(s):  
Business Education ◽  
Survey Method ◽  
Test Statistics ◽  
Education Curriculum ◽  
Graduate Level ◽  
Tertiary Institutions ◽  
Course Content ◽  
The Core ◽  
The Mean

The paper focuses on enhancing quality through the harmonization of business education curricular across the globe and Nigerian universities in particular. 35 graduate students from three tertiary institutions were randomly selected and 15 lecturers in business education were the sample subjects. The survey method was used to determine the effects of lack of uniformity in business education curriculum at graduate level the mean and standard deviation were used to analyze the items. The t-test statistics method was also used. It was found out that there was lack of uniformity in the curricula of business education at graduate level among other things. The paper recommends that supervisory authorities should harmonize the curricula of business education to ensure uniformity in tertiary institutions particularly at graduate level and to enhance and ensure quality of the programme. It also recommends that 80% of the course content in the core option areas be incorporated into the curriculum to enhance performance and learning outcome and avoid functional dilemma of expectation and realities.

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