Hydration of synthetic polypropylenephosphate (PPP) ? a simplified model for natural teichoic acids Part 3. Bound (nonfreezing) water in PPP gels by the pulsed Fourier transform NMR method

1987 ◽  
Vol 265 (2) ◽  
pp. 106-112 ◽  
Author(s):  
M. Litowska ◽  
H. D�hler
Keyword(s):  
Fourier Transform ◽  
Simplified Model ◽  
Teichoic Acids ◽  
Nmr Method

Study of Configurational Sequence Structures of Poly(Butadiene)s by Carbon-13 Proton Decoupled Fourier Transform Nuclear Magnetic Resonance Spectroscopy

1973 ◽  
Vol 46 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Yasuhide Alaki ◽  
Toshio Yoshimoto ◽  
Mamoru Imanari ◽  
Makoto Takeuchi
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Polymer Chains ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Sequence Structure ◽  
Nmr Method ◽  
Nuclear Magnetic

Abstract Carbon-13 proton nuclear magnetic resonance (NMR) of poly(butadiene) s consisting of various ratios of cis-1,4-, trans-1,4- and 1,2-structures were measured by the pulsed Fourier transform NMR method. The spectra of poly(butadiene)s with two or three kinds of butadiene configurations show several new signals which were not observed for homopolymers comprising merely one kind of butadiene configuration. All of these peaks are ascribed to the carbons linked by different kinds of configurations. From these results, the configurational sequence structure of butadiene units in polymer chains has been revealed.

Fourier Analysis Guided Cable Actuator Design for Coordinated Walking Assistance

2021 ◽  
Author(s):  
Chong Liu ◽  
Rand Hidayah ◽  
Sunil Agrawal
Keyword(s):  
Fourier Transform ◽  
Curve Fitting ◽  
Degrees Of Freedom ◽  
State Of The Art ◽  
Simplified Model ◽  
Forward Kinematics ◽  
Joint Angles ◽  
Sine Curve ◽  
Design And Manufacture ◽  
Actuator Design

Abstract Cable-driven exoskeletons add minimal inertia and restrictions to the user’s leg while still providing feedback and quantitative measures of the user’s performance. However, cable robots require at least n + 1 cables to control n degrees-of-freedom, i.e., they require more actuators than the leg’s degrees-of-freedom, challenging their widespread adoption as wearable technology. The state-of-the-art in this field aims to reduce the number of actuated motors. In this paper, we design and evaluate a “single motor-driven” leg exoskeleton prototype based on the Cable-driven Active Leg EXoskleton (C-ALEX). The prototype consists of four crank-spring mechanisms and a crankshaft designed using epicycle analysis. The epicycle analysis is performed using discrete Fourier transform (DFT) and sine curve fitting (SCF). While DFT suggests the maximum number of epicycles to imitate the target waveform, a large number of nested epicycles is challenging to design and manufacture for implementation. To validate the epicycle-guided design, we constructed a simple crankshaft model using one epicycle. Our proposed simplified model predicted and produced the joint angles calculated from the inverse and forward kinematics of a cable-driven leg exoskeleton with multiple motors. To our knowledge, this is the first multi-cable driven exoskeleton powered by a single actuator that is designed to provide continuous assistance to the user.

Étude des bandes infrarouges en résonance 2ν2, ν2 + ν5, , , 2ν3 + ν5 et 4ν3 du chlorure de méthyle

1982 ◽  
Vol 60 (6) ◽  
pp. 825-843 ◽  
Author(s):  
Najath Binsari-Zizi ◽  
Claude Alamichel ◽  
Guy Guelachvili
Keyword(s):  
Fourier Transform ◽  
Standard Deviation ◽  
High Resolution ◽  
Least Squares ◽  
Methyl Chloride ◽  
Coupling Model ◽  
Fermi Resonance ◽  
Simplified Model ◽  
Interaction Scheme ◽  
Very High

The spectrum of methyl chloride has been analyzed between 2650 and 2950 cm−1 from Fourier transform recordings obtained with a very high resolution. More than 3000 lines of CH335Cl and more than 1500 lines of CH337Cl, most of them belonging to ν2 + ν5 and [Formula: see text], have been assigned: the 2ν2, [Formula: see text], 4ν3 and 2ν3 + ν5 bands are very weak and only appear when there are level crossings. The main interaction is the Coriolis resonance between the ν2 and ν5 modes, which links the rovibrational levels six by six. The Fermi resonance between [Formula: see text] and ν1, whose existence has just been shown, does not seem to have important consequences. Numerous other resonances, particularly making the 4ν3 and 2ν3 + ν5 bands visible, must be added to the basic coupling model; they make the general interaction scheme extremely complex. A least squares calculation, according to a simplified model, has given a standard deviation of 0.029 cm−1 over 784 lines of CH337Cl, from which crossings and locally perturbed subbands were excluded.

Study of a structural phase transition by two dimensional Fourier transform NMR method

1985 ◽  
Vol 55 (11) ◽  
pp. 929-931 ◽  
Author(s):  
A. Trokiner ◽  
P.P. Man ◽  
H. Théveneau ◽  
P. Papon
Keyword(s):  
Phase Transition ◽  
Fourier Transform ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Two Dimensional ◽  
Nmr Method

Hydration of synthetic polydialkylphosphate (PPF) ? a simplified model for natural teichoic acids

1984 ◽  
Vol 262 (6) ◽  
pp. 455-460 ◽  
Author(s):  
M. Litowska ◽  
A. Narebska
Keyword(s):  
Simplified Model ◽  
Teichoic Acids

scholarly journals Regular nonlinear generalized functions and applications

2006 ◽  
Vol 133 (31) ◽  
pp. 163-174 ◽  
Author(s):  
A. Delcroix
Keyword(s):  
Fourier Transform ◽  
Integral Operators ◽  
Generalized Functions ◽  
Regular Growth ◽  
Simplified Model ◽  
Local Analysis ◽  
Schwartz Kernel ◽  
Linear Maps ◽  
Nonlinear Generalized Functions ◽  
Kernel Theorem

We present new types of regularity for Colombeau nonlinear generalized functions, based on the notion of regular growth with respect to the regularizing parameter of the simplified model. This generalizes the notion of G8-regularity introduced by M. Oberguggenberger. As a first application we show that these new spaces are useful in a problem of representation of linear maps by integral operators, giving an analogon to Schwartz kernel theorem in the framework of nonlinear generalized functions. Secondly, we remark that these new regularities can be characterized, for compactly supported generalized functions, by a property of their Fourier transform. This opens the door to micro local analysis of singularities of generalized functions, with respect to these regularities. AMS Mathematics Subject Classification (2000): 35A18, 35A27, 42B10, 46E10, 46F30.

scholarly journals Development and Validation of a Simple Method to Quantify Contents of Phospholipids in Krill Oil by Fourier-Transform Infrared Spectroscopy

Foods ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Se-Eun Park ◽  
Hyo-Yeon Yu ◽  
Sangdoo Ahn
Keyword(s):  
Fourier Transform ◽  
31P Nmr ◽  
Limit Of Detection ◽  
Fourier Transform Infrared ◽  
Raw Material ◽  
Krill Oil ◽  
Simple Method ◽  
Nmr Method ◽  
Relative Standard ◽  
Ft Ir

This study focuses on developing a quantification method for phosphatidylcholine (PC) and total phospholipid (PL) in krill oil using Fourier-transform infrared (FT-IR) spectroscopy. Signals derived from the choline and phosphate groups were selected as indicator variables for determining PC and total PL content; calibration curves with a correlation coefficient of >0.988 were constructed with calibration samples prepared by mixing krill oil raw material and fish oil in different ratios. The limit of detection (LOD, 0.35–3.29%) of the method was suitable for the designed assay with good accuracy (97.90–100.33%). The relative standard deviations for repeatability (0.90–2.31%) were acceptable. Therefore, both the methods using absorbance and that using second-derivative were confirmed to be suitable for quantitative analysis. When applying this method to test samples, including supplements, the PC content and total PL content were in good agreement with an average difference of 2–3% compared to the 31P NMR method. These results confirmed that the FT-IR method can be used as a convenient and rapid alternative to the 31P NMR method for quantifying PLs in krill oil.

Fourier-Kernresonanzuntersuchungen an 10 B und 11 B in wäßriger Lösung / Fourier Transform NMR Studies of 10 B and 11 B in Aqueous Solutions

1975 ◽  
Vol 30 (8) ◽  
pp. 955-958 ◽  
Author(s):  
B. W. Epperlein ◽  
. Lutz ◽  
A. Schwenk
Keyword(s):  
Fourier Transform ◽  
Aqueous Solutions ◽  
Hyperfine Interaction ◽  
Magnetic Moment ◽  
Ground State ◽  
Magnetic Shielding ◽  
Nmr Studies ◽  
Nmr Method ◽  
Atomic Ground State ◽  
Nmr Signals

Abstract The ratios of the Larmor frequencies of 10 B and 2 H and of 11 B and 10 B have been measured with the NMR method and a magnetic moment has been calculated for 10 B in the B (OH)4- -ion. For this, an investigation of the dependence of the NMR signals of 10 B and 2 H on the concentration of some boron salts in solutions of H2O and D2O was necessary. Using hyperfine interaction constants from literature, the hyperfine structure anomaly 10 ∆ 11 of boron in the 2 P1/2 atomic ground state has been calculated. A difference in the magnetic shielding between the isotopes 10 B and 11 B in different compounds could not be detected.

Comparison of Calculated and Recorded Electron Energy-Loss Spectra of Aluminium and Carbon

1990 ◽  
Vol 48 (2) ◽  
pp. 64-65
Author(s):  
L. Reimer ◽  
R. Oelgeklaus
Keyword(s):  
Fourier Transform ◽  
Energy Loss ◽  
Electron Energy ◽  
Rotational Symmetry ◽  
Mean Free Path ◽  
Single Scattering ◽  
Specimen Thickness ◽  
Two Dimensional ◽  
Image Position ◽  
Electron Energy Loss

Quantitative electron energy-loss spectroscopy (EELS) needs a correction for the limited collection aperture α and a deconvolution of recorded spectra for eliminating the influence of multiple inelastic scattering. Reversely, it is of interest to calculate the influence of multiple scattering on EELS. The distribution f(w,θ,z) of scattered electrons as a function of energy loss w, scattering angle θ and reduced specimen thickness z=t/Λ (Λ=total mean-free-path) can either be recorded by angular-resolved EELS or calculated by a convolution of a normalized single-scattering function ϕ(w,θ). For rotational symmetry in angle (amorphous or polycrystalline specimens) this can be realised by the following sequence of operations :(1)where the two-dimensional distribution in angle is reduced to a one-dimensional function by a projection P, T is a two-dimensional Fourier transform in angle θ and energy loss w and the exponent -1 indicates a deprojection and inverse Fourier transform, respectively.

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