A New Nonslender Ringing Load Approach Verified Against Experiments

1998 ◽  
Vol 120 (1) ◽  
pp. 20-29 ◽  
Author(s):  
J. R. Krokstad ◽  
C. T. Stansberg ◽  
A. Nestega˚rd ◽  
T. Marthinsen
Keyword(s):  
Wave Model ◽  
Second Order ◽  
Wave Load ◽  
Peak Wavelength ◽  
Third Order ◽  
Load Model ◽  
Order Analysis ◽  
First Order ◽  
Load Effects ◽  
Vertical Cylinders

New results from the most recent work within the Norwegian Joint Industry Project (JIP) “Higher Order Wave Load Effects on Large Volume Structures” are presented. A nonslender theoretical model is validated from experiments for two fixed, vertical cylinders with different diameter/peak wavelength ratios. A combination of complete diffraction first-order simulations, sum and difference frequency second-order simulations, and third-order FNV (Faltinsen, Newman, and Vinje, nonlinear long wave model) is implemented in order to develop a simplified and robust ringing load model for a large range of cylinder diameter/peak wavelength ratios. Results from the full diffraction second-order analysis show a significant reduction of second-order loads compared to pure FNV in the wavelength range relevant for ringing loads. The results show improved correspondence with high-frequency experimental loads compared with the unmodified FNV. Results for different cylinder peak wavelength ratios are presented, including validation against experiments. In addition, a few simplified response simulations are carried out demonstrating significant improvements with the modified FNV model.

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

Panicle, spikelet, and floret development in orchardgrass (Dactylis glomerata)

1993 ◽  
Vol 71 (4) ◽  
pp. 523-532 ◽  
Author(s):  
Joanna Fraser ◽  
Eric G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Unique Feature ◽  
Dactylis Glomerata ◽  
Bilateral Symmetry ◽  
Second Order ◽  
Third Order ◽  
First Order ◽  
Lateral Branches ◽  
Scanning Electron

The initial stages of panicle, spikelet, and floret development in field-grown 'Kay' orchardgrass were examined using scanning electron microscopy. Spikelets arose from a complex multilevelled sequence of initiation from branch apices. Spikelets developed indirectly in a two-tiered progression: (i) an acropetal and basipetal sequence of first order, second-order, and third-order inflorescence apices, and (ii) an acropetal development within subclusters of higher-order lateral branch inflorescence apices. The panicle had the unique feature of dorsiventrality as well as bilateral symmetry. The basal apex from first-order, second-order, or third-order apices developed on the same side of the main axis as the first-order apex. The two glumes subtending each spikelet primordium developed alternately and acropetally. Development and initiation of florets within spikelets was basipetal within the panicle, basipetal within clusters and subclusters of spikelets on lateral branches, and acropetal within spikelets. Within florets, paleas developed later than lemmas. Key words: Dactylis glomerata, cocksfoot, scanning electron microscopy, development, panicle.

An approach to combine the second-order and third-order analysis methods for optimization of a Stirling engine

2018 ◽  
Vol 165 ◽  
pp. 447-458 ◽  
Author(s):  
Gang Xiao ◽  
Yiqing Huang ◽  
Shulin Wang ◽  
Hao Peng ◽  
Mingjiang Ni ◽  
...  
Keyword(s):  
Stirling Engine ◽  
Second Order ◽  
Third Order ◽  
Order Analysis ◽  
Analysis Methods

A Note on Homogeneous Dendrites

1968 ◽  
Vol 11 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Z. A. Melzak
Keyword(s):  
Branch Point ◽  
Rooted Tree ◽  
Second Order ◽  
Third Order ◽  
First Order ◽  
Graph Theoretic ◽  
Order Branch

In graph - theoretic terms a homogeneous p-dendrite, p ≥ 2, is defined as a finite singly-rooted tree in which the root has valency 1 while every other vertex has valency 1 or p. More descriptively, a homogeneous p-dendrite may be imagined to start from its root as the main, or 0th order, branch which proceeds to the first - order branch point where it gives rise top first - order branches. Each of these either terminates at its other end (which is a second-order branch point) or it splits there again into p branches (which are of third order), and so on. The order of the dendrite is the highest order of a branch present in it. For completeness, a 0-th order dendrite is also allowed, this consists of the 0-th order branch alone.

Differences in EDNO contribution to arteriolar diameters at rest and during functional dilation in striated muscle

1993 ◽  
Vol 265 (1) ◽  
pp. H146-H151 ◽  
Author(s):  
R. L. Hester ◽  
A. Eraslan ◽  
Y. Saito
Keyword(s):  
Striated Muscle ◽  
Physiological Role ◽  
Second Order ◽  
Muscle Stimulation ◽  
Third Order ◽  
First Order ◽  
Before And After ◽  
Arteriolar Vasodilation ◽  
Arteriolar Diameter

This study was designed to determine the physiological role of endothelium-dependent nitric oxide (EDNO) in the control of arteriolar diameter during rest and muscle stimulation. Diameters of first-, second-, and third-order arterioles in the superfused hamster cremaster muscle were measured before and throughout 1 min of field stimulation before and after inhibition of EDNO release. ENDO inhibition by intravenous N omega-nitro-L-arginine methyl ester (L-NAME) significantly attenuated the arteriolar vasodilation in response to 1 microM acetylcholine. First-order arterioles averaged 65 +/- 5 microns at rest and dilated to 86 +/- 6 microns during muscle stimulation (n = 9), second-order arterioles averaged 45 +/- 6 microns and dilated to 72 +/- 3 microns during muscle stimulation (n = 6), with third-order arterioles averaging 29 +/- 2 microns, and dilating to 53 +/- 3 microns during muscle stimulation (n = 7). EDNO inhibition significantly decreased both the resting diameter of first-order arterioles (57 +/- 4 microns) and functional dilation (68 +/- 3 microns; P <0.05). EDNO inhibition had no effect on the resting diameter of second-order arterioles (45 +/- 5 microns) yet significantly attenuated the functional dilation (64 +/- 4 microns; P < 0.05). EDNO inhibition had no effect on either the resting diameter of third-order arterioles (30 +/- 2 microns) or the functional dilation (49 +/- 2 microns).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Clustering for semantic purposes

Terminology ◽  
2014 ◽  
Vol 20 (2) ◽  
pp. 279-303 ◽  
Author(s):  
Ann Bertels ◽  
Dirk Speelman
Keyword(s):  
Semantic Analysis ◽  
Second Order ◽  
Scaling Analysis ◽  
Distributional Semantics ◽  
Semantic Heterogeneity ◽  
Multidimensional Scaling Analysis ◽  
Third Order ◽  
Clustering Techniques ◽  
First Order ◽  
Fine Grained

This paper presents an innovative approach, within the framework of distributional semantics, for the exploration of semantic similarity in a technical corpus. In complement to a previous quantitative semantic analysis conducted in the same domain of machining terminology, this paper sets out to discover fine-grained semantic distinctions in an attempt to explore the semantic heterogeneity of a number of technical items. Multidimensional scaling analysis (MDS) was carried out in order to cluster first-order co-occurrences of a technical node with respect to shared second-order and third-order co-occurrences. By taking into account the association values between relevant first and second-order co-occurrences, semantic similarities and dissimilarities between first-order co-occurrences could be determined, as well as proximities and distances on a graph. In our discussion of the methodology and results of statistical clustering techniques for semantic purposes, we pay special attention to the linguistic and terminological interpretation.

Second-Order Diffraction Forces on an Array of Vertical Cylinders in Bichromatic Bidirectional Waves

1995 ◽  
Vol 117 (1) ◽  
pp. 12-18 ◽  
Author(s):  
J. H. Vazquez ◽  
A. N. Williams
Keyword(s):  
Cross Section ◽  
Finite Depth ◽  
Hydrodynamic Forces ◽  
Arbitrary Cross Section ◽  
Second Order ◽  
Order Problem ◽  
First Order ◽  
Wave Directionality ◽  
Vertical Cylinders ◽  
Green Function Approach

A complete second-order solution is presented for the hydrodynamic forces due to the action of bichromatic, bidirectional waves on an array of bottom-mounted, surface-piercing cylinders of arbitrary cross section in water of uniform finite depth. Based on the constant structural cross section, the first-order problem is solved utilizing a two-dimensional Green function approach, while an assisting radiation potential approach is used to obtain the hydrodynamic loads due to the second-order potential. Results are presented which illustrate the influence of wave directionality on the second-order sum and difference frequency hydrodynamic forces on a two-cylinder array. It is found that wave directionality may have a significant influence on the second-order hydrodynamic forces on these arrays and that the assumption of unidirectional waves does not always lead to conservative estimates of the second-order loading.

Perturbation treatment of the Hartree–Fock equations for the ground states of the boron-like ions

1969 ◽  
Vol 47 (7) ◽  
pp. 699-705 ◽  
Author(s):  
C. S. Sharma ◽  
R. G. Wilson
Keyword(s):  
Ground State ◽  
Atomic System ◽  
Ground States ◽  
Great Accuracy ◽  
Second Order ◽  
Expectation Values ◽  
Third Order ◽  
First Order ◽  
Hartree Fock ◽  
The Third

The first-order Hartree–Fock and unrestricted Hartree–Fock equations for the ground state of a five electron atomic system are solved exactly. The solutions are used to evaluate the corresponding second-order energies exactly and the third-order energies with great accuracy. The first-order terms in the expectation values of 1/r, r, r2, and δ(r) are also calculated.

scholarly journals Euler-Bernoulli Beam Theory: First-Order Analysis, Second-Order Analysis, Stability, and Vibration Analysis Using the Finite Difference Method

2021 ◽  
Author(s):  
Valentin Fogang
Keyword(s):  
Finite Difference ◽  
Beam Theory ◽  
Second Order ◽  
Governing Equations ◽  
Deflection Curve ◽  
Order Analysis ◽  
First Order ◽  
Finite Difference Approximations ◽  
Order Polynomial ◽  
Euler Bernoulli Beam

This paper presents an approach to the Euler-Bernoulli beam theory (EBBT) using the finite difference method (FDM). The EBBT covers the case of small deflections, and shear deformations are not considered. The FDM is an approximate method for solving problems described with differential equations. The FDM does not involve solving differential equations; equations are formulated with values at selected points of the structure. Generally, the finite difference approximations are derived based on fourth-order polynomial hypothesis (FOPH) and second-order polynomial hypothesis (SOPH) for the deflection curve; the FOPH is made for the fourth and third derivative of the deflection curve while the SOPH is made for its second and first derivative. In addition, the boundary conditions and not the governing equations are applied at the beam&rsquo;s ends. In this paper, the FOPH was made for all of the derivatives of the deflection curve, and additional points were introduced at the beam&rsquo;s ends and positions of discontinuity (concentrated loads or moments, supports, hinges, springs, etc.). The introduction of additional points allowed us to apply the governing equations at the beam&rsquo;s ends and to satisfy the boundary and continuity conditions. Moreover, grid points with variable spacing were also considered, the grid being uniform within beam segments. First-order analysis, second-order analysis, and vibration analysis of structures were conducted with this model. Furthermore, tapered beams were analyzed (element stiffness matrix, second-order analysis). Finally, a direct time integration method (DTIM) was presented. The FDM-based DTIM enabled the analysis of forced vibration of structures, with damping taken into account. The results obtained in this paper showed good agreement with those of other studies, and the accuracy was increased through a grid refinement. Especially in the first-order analysis of uniform beams, the results were exact for uniformly distributed and concentrated loads regardless of the grid. Further research will be needed to investigate polynomial refinements (higher-order polynomials such as fifth-order, sixth-order&hellip;) of the deflection curve; the polynomial refinements aimed to increase the accuracy, whereby non-centered finite difference approximations at beam&rsquo;s ends and positions of discontinuity would be used.

Sign in / Sign up

Export Citation Format

Share Document