scholarly journals Improved precision of hydraulic conductance measurements using a Cochard rotor in two different centrifuges

2014 ◽  
Vol 1 ◽  
pp. e007 ◽  
Author(s):  
Yujie Wang ◽  
Régis Burlett ◽  
Feng Feng ◽  
Melvin T. Tyree
Keyword(s):  
Relative Error ◽  
Computational Algorithm ◽  
Temperature Stability ◽  
Hydraulic Conductance ◽  
Water Levels ◽  
Computational Method ◽  
New Approach ◽  
Temperature Changes ◽  
Stem Temperature ◽  
Discrete Values

An improved way ofcalculating hydraulic conductance (K) in a Cochard cavitron is described. UsuallyK is determined by measuring how fast water levels equilibrate between two reservoirs while a stem spins in a centrifuge. A regression of log meniscus position versus time was used to calculate K and this regression method was compared to the old technique that takes the average of discrete values. Results of a hybrid Populus 84K shows that the relative error of the new approach is significantly lower than the old technique by 4~5 times. The new computational method results in a relative error less than 0.5% or 0.3% from 8 or 12 points of measurement, respectively. The improved precision of K measurement also requires accurate assessment of stem temperature because temperature changes K by 2.4% oC-1. A computational algorithm for estimating stem temperature stability in a cavitron rotor was derived. This algorithm provides information on how long it takes stem temperature to be known to within an error of ±0.1oC.

Application of pyrometer and standard sample to determine surface temperature of studied materials

2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov
Keyword(s):  
Composite Material ◽  
Surface Temperature ◽  
Relative Error ◽  
Wavelength Range ◽  
Standard Sample ◽  
A Priori ◽  
Temperature Changes ◽  
Surface Temperatures ◽  
Relative Errors ◽  
Normal Emissivity

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.

Fractional Order Derivative and Integral Computation with a Small Number of Discrete Input Values Using Grünwald–Letnikov Formula

2019 ◽  
Vol 17 (05) ◽  
pp. 1940006
Author(s):  
Dariusz W. Brzeziński
Keyword(s):  
Input Data ◽  
Fractional Derivatives ◽  
Difficult Problem ◽  
Computational Method ◽  
Problem Solution ◽  
Fractional Derivatives And Integrals ◽  
Discrete Values ◽  
Arbitrary Precision ◽  
Modern Programming Language ◽  
Accuracy Of Approximation

High-accuracy computer approximation of fractional derivatives and integrals by applying Grünwald–Letnikov formula generally requires a large number of input values. If required amount cannot be supplied, accuracy of approximation drops drastically. In this paper, we solve a difficult problem in this scope, i.e., when input data consists only of a small number of discrete values. Furthermore, some of the values may be unusable for computational purposes. Our problem solution includes an appropriate method of input data preprocessing, an interpolation algorithm with extrapolation abilities, a central point function discretization schema, recurrent computational method of coefficients and application of Horner’s schema for the core of the Grünwald–Letnikov method: coefficients and function’s values multiplication. Numerical method presented in the paper enables to compute fractional derivatives and integrals of complicated functions with much higher accuracy than it is possible when application of the default approach to Grünwald–Letnikov method computer implementation is applied. This new method usually takes only 10% of function’s values required by the default approach for the same computations and is much less restrictive for their quality. The general novelty of the method is an efficient configuration of existing numerical methods and enhancement of their abilities by applying modern programming language — Python and arbitrary precision arithmetic for computations.

scholarly journals A new approach for the removal of unfixed dyes from reactive dyed cotton by Fenton oxidation

2019 ◽  
Vol 9 (2) ◽  
pp. 133-141
Author(s):  
Sana Islam ◽  
Irfan Ahmed Shaikh ◽  
Nabeela Firdous ◽  
Azhar Ali ◽  
Yumna Sadef
Keyword(s):  
Treatment Time ◽  
Color Difference ◽  
Quality Parameters ◽  
Water Levels ◽  
Fenton Oxidation ◽  
Color Strength ◽  
New Approach ◽  
Reactive Dyeing ◽  
The Difference ◽  
Day By Day

Abstract The use of fresh water in the textile wash-off process is becoming more expensive day by day due to declining water levels in the region. In this study, the potential of using Fenton oxidation in wash-off cotton reactive dyeing was investigated. The spent wash-off wastewater from one dyeing was first treated with Fenton oxidation, and then reused in several washing-offs employing widely used reactive dyes, C.I. Reactive Yellow 145, C.I. Reactive Blue 21, and C.I. Reactive Red 195. Experimental results showed that at acidic pH (3) using optimized quantities of FeSO4 and H2O2, Fenton process yielded a significant reduction (90–95%) of color in 30 minutes of treatment time. New washing-offs were then carried out in Fenton decolorized wash-off wastewater, and dyed cotton fabric samples were subjected to quality evaluations in terms of color difference properties (ΔL*, Δc*,Δb*, Δa*, ΔE*cmc) and wash fastness properties. This study concluded that after Fenton oxidation, treated liquor can be effectively reused subsequent washing-offs without compromising fabric quality parameters as ΔE*cmc was less than 1, and washing and crocking was also in the range of 4.5–5 which is commercially acceptable. Moreover, the difference in color strength in terms of k/s was also negligible.

Temperature relevant performance and calibration of spin-valve sensor

Sensor Review ◽  
2019 ◽  
Vol 39 (6) ◽  
pp. 881-886
Author(s):  
Huachen Zhu ◽  
Zhenghong Qian ◽  
Jiaofeng Zhang ◽  
Yucheng Sun ◽  
Ru Bai ◽  
...  
Keyword(s):  
Spin Valve ◽  
Temperature Stability ◽  
Lower Sensitivity ◽  
Temperature Drift ◽  
Content Type ◽  
Temperature Changes ◽  
Drift Model ◽  
Higher Temperature ◽  
Highly Correlated ◽  
The Relationship

Purpose It has been noted that the spin-valve sensor exhibits lower sensitivity with higher temperature because of the variation of GMR ratio, which could lead to the measurement error in applications where working temperature changes largely over seasons or times. This paper aims to investigate and compensate the temperature effect of the spin-valve sensor. Design/methodology/approach A spin-valve sensor is fabricated based on microelectronic process, and its temperature relevant properties are investigated, in which the transfer curves are acquired within a temperature range of −50°C to 125°C with a Helmholtz coil and temperature chamber. Findings It is found that the sensitivity of spin-valve sensor decreases with temperature linearly, where the temperature coefficient is calculated at −0.25 %/°C. The relationship between sensitivity of spin-valve sensor and temperature is well-modeled. Originality/value The temperature drift model of the spin-valve sensor’s sensitivity is highly correlated with tested results, which could be used to compensate the temperature influence on the sensor output. A self-compensation sensor system is proposed and built based on the expression modeled for the temperature dependence of the sensor, which exhibits a great improvement on temperature stability.

Neonatal Thermoregulation: Bed Surface Transfers

1999 ◽  
Vol 18 (4) ◽  
pp. 35-38 ◽  
Author(s):  
Leslie Altimier ◽  
Barbara Warner ◽  
Stephanie Amlung ◽  
Carole Kenner
Keyword(s):  
Birth Weight ◽  
Preterm Infants ◽  
Temperature Stability ◽  
Outcome Variable ◽  
Convenience Sample ◽  
Temperature Changes ◽  
Baseline Temperature ◽  
Main Outcome Variable ◽  
Radiant Warmer

Purpose: To describe temperature changes that occur in preterm infants following bed surface transfers.Design: The design was descriptive.Sample: The convenience sample was comprised of 20 preterm infants (<1,500 gm birth weight).Main outcome variable: Temperature stability after a bed transfer (i.e., radiant warmer to incubator) was the main outcome variable.Results: There were no significant differences in temperatures after bed surface transfer. However, the temperatures one hour after bed surface transfer were lower than baseline temperature before bed surface transfer.

A new computational method for the solution of flow problems of microstructured fluids. Part 2. Inhomogeneous shear flow of a suspension

1994 ◽  
Vol 262 ◽  
pp. 171-204 ◽  
Author(s):  
Andrew J. Szeri ◽  
L. Gary Leal
Keyword(s):  
Planck Equation ◽  
Orientation Distribution ◽  
Companion Paper ◽  
Computational Method ◽  
Flat Plates ◽  
New Approach ◽  
Flow Problems ◽  
Closure Approximations ◽  
Rigid Rod ◽  
Microstructured Fluids

A numerical investigation is conducted into the flow of a dilute suspension of rigid rod-like particles between parallel flat plates, driven by a uniform pressure gradient. The particles are assumed to be small relative to lengthscales of the flow with the effect that particle orientations evolve according to the local velocity gradient; the particles are also assumed to be small in an absolute sense, with the consequence that Brownian motions are of consequence. The calculations are performed using a novel approach, with a theoretical basis that has been developed previously in a companion paper (Szeri & Leal 1992). The new approach permits one to solve flow problems of microstructured fluids (such as suspensions, liquid crystals, polymer solutions and melts) without ‘pre-averaging’ or closure approximations. In the present work, the new approach is used to expose previously unknown pathological, non-physical predictions in various constitutive models derived using closure approximations. This appears to have passed unnoticed in prior work. In addition, the new approach is shown to possess several computational advantages. The determination of the orientation distribution of particles is self-adaptive; this leads, in effect, to a very efficient solution of the associated Smoluchowski (or Fokker–Planck) equation. Moreover, the new approach is highly suited to parallel (and vector) implementation on modern computers. These issues are explored in detail in the context of the example flow.

scholarly journals Fast Moving Objects Detection Using iLBP Background Model

2014 ◽  
Vol XL-3 ◽  
pp. 347-350 ◽  
Author(s):  
B. Vishnyakov ◽  
V. Gorbatsevich ◽  
S. Sidyakin ◽  
Y. Vizilter ◽  
I. Malin ◽  
...  
Keyword(s):  
Moving Objects ◽  
Computational Algorithm ◽  
Image Representation ◽  
Local Binary Patterns ◽  
Surveillance Systems ◽  
New Approach ◽  
Moving Objects Detection ◽  
Proposed Model ◽  
Objects Detection ◽  
Background Models

In this paper a new approach for moving objects detection in video surveillance systems is proposed. It is based on iLBP (intensity local binary patterns) descriptor that combines the classic LBP (local binary patterns) and the multiple regressive pseudospectra model. The iLBP descriptor itself is considered together with computational algorithm that is based on the sign image representation. We show that motion analysis methods based on iLBP allow uniformly detecting objects that move with different speed or even stop for a short while along with unattended objects. We also show that proposed model is comparable to the most popular modern background models, but is significantly faster.

scholarly journals BaTiO3 films for multilayer devices by tape casting

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
S. Ivanchenko ◽  
S. Umerova ◽  
D. Baranovskyi ◽  
O. Kovalenko ◽  
A. Ragulya
Keyword(s):  
Surface Roughness ◽  
Printed Electronics ◽  
Tape Casting ◽  
Practical Implementation ◽  
Nanosized Powders ◽  
New Approach ◽  
Temperature Changes ◽  
Nanostructured Ceramic ◽  
Polymer Ratio

The diversity of the applicational scope of modern printed electronics relentlessly requires the improvement of operational properties simultaneously with reducing the overall dimensions of devices. One of the most effective ways to overcome this major obstacle is the reduction of functional layers thickness in respect to the size of the device. In the present article, we are discussing a simple way of practical implementation of miniaturization concept through the application of a well-known high-productive industrial method of tape casting for obtaining thin nanostructured ceramic layers based on BaTiO3 nanopowders for MLCC. Using of nanosized powders per se imply a new approach of developing suspensions with suitable rheology for tape casting. We demonstrate, that a length of polymer molecule defines the size of floccules and therefore influences the thickness and surface quality of tape casted films. A certain nanopowder/polymer ratio contributes to the formation of the tapes with the surface roughness comparable with the size of one nanoparticle (20-25 nm). Moreover, it was established that developed suspensions are extremely sensitive to temperature changes. Lowering the temperature significantly affects the flow character of suspension and thus the thickness of casted tapes. Considering this fact, we propose an effective self-developed pre-cooling method of nanopowder suspension casting, which allows obtaining extremely thin and smooth tapes with a thickness of less than 1 µm and surface roughness of 20–25 nm by tape casting method.

scholarly journals Backtracking-free Interactive Music Scores with Temporal Relations over Rythms

2018 ◽  
Author(s):  
Mauricio Toro
Keyword(s):  
Local Search ◽  
Optimization Problems ◽  
Computational Method ◽  
Constraint Solving ◽  
Adaptive Search ◽  
Interactive Music ◽  
Candidate Solution ◽  
Approximative Solution ◽  
Optimization Function ◽  
Discrete Values

Another alternative to solve CSP s is to use (incomplete) local search algorithmsto find interatively an approximative solution. Local search is a metaheuristic forsolving computationally hard optimization problems. An example of local searchis adaptive search: A computational method that optimizes a problem by iterativelytrying to improve a candidate solution with regard to the problem constraints (andpossibly an optimization function). In spite of the advances in constraint solving for music compositions problems,as far as we know, there is little research on solving CSP s during real-time music interaction. In this paper we will focus on interactive scores, a formalism for thedesign of interactive scenarios closely related to constraint programming. we do not have a polynomial algorythm to solve all instances ofthe problem. Consider, for instance, the case where the durations of the temporalobjects are not singles values nor intervals, but discrete values.

scholarly journals THE REPRODUCING KERNEL ALGORITHM FOR NUMERICAL SOLUTION OF VAN DER POL DAMPING MODEL IN VIEW OF THE ATANGANA–BALEANU FRACTIONAL APPROACH

Fractals ◽  
2020 ◽  
Vol 28 (08) ◽  
pp. 2040010 ◽  
Author(s):  
SHAHER MOMANI ◽  
BANAN MAAYAH ◽  
OMAR ABU ARQUB
Keyword(s):  
Numerical Simulations ◽  
Numerical Solution ◽  
Reproducing Kernel ◽  
Computational Algorithm ◽  
Mathematical Structure ◽  
The Other ◽  
Modern Trend ◽  
Van Der Pol ◽  
New Approach ◽  
Damping Model

The aim of this paper is to propose the Atangana–Baleanu fractional methodology for fathoming the Van der Pol damping model by using the reproducing kernel algorithm. To this end, we discuss the mathematical structure of this new approach and some other numerical properties of solutions. Furthermore, all needed requirements for characterizing solutions by applying the reproducing kernel algorithm are debated. In this orientation, modern trend and new computational algorithm in terms of analytic and approximate Atangana–Baleanu fractional solutions are proposed. Finally, numerical simulations in fractional emotion is constructed one next to the other with tabulated data and graphical portrayals.

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