scholarly journals Definitely Islands? Experimental investigation of definite islands

2021 ◽  
Vol 1 ◽  
pp. 237
Author(s):  
Anissa Neal ◽  
Brian Dillon
Keyword(s):  
Experimental Investigation ◽  
Experimental Work ◽  
Island Effect ◽  
Reading Experiment ◽  
Online Measures ◽  
Acceptability Judgment

Experimental work on islands has used formal acceptability judgment studies to quantify the severity of different island violations. This current study uses this approach to probe the (in-)violability of definite islands, an understudied island, in offline and online measures. We conducted two acceptability judgment studies and find a modest island effect. However, rating distributions appear bimodal across definites and indefinites. We also conducted a self-paced reading experiment, but found no sig- nificant effects. Overall, offline, definite islands differ from other uniform islands, but online, the results are more complicated.

scholarly journals Experimental Investigation of the Prestrike Characteristics of a Double-Break Vacuum Circuit Breaker under DC Voltages

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3217
Author(s):  
Yun Geng ◽  
Xiaofei Yao ◽  
Jinlong Dong ◽  
Xue Liu ◽  
Yingsan Geng ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Direct Current ◽  
Experimental Work ◽  
Low Voltage ◽  
Circuit Breaker ◽  
Circuit Breakers ◽  
Vacuum Circuit Breaker ◽  
In Series ◽  
The Difference ◽  
Single Break

The prestrike phenomenon in vacuum circuit breakers (VCBs) is interesting but complicated. Previous studies mainly focus on the prestrike phenomenon in single-break VCBs. However, experimental work on prestrike characteristics of double-break VCBs cannot be found in literature. This paper aims to experimentally determine the probabilistic characteristics of prestrike gaps in a double-break VCB consisting of two commercial vacuum interrupters (VIs) in series under direct current (DC) voltages. As a benchmark, single-break prestrike gaps were measured by short-circuiting one of the VIs in a double break. The experimental results show that the 50% prestrike gap d50 of each VI in a double break, which is calculated with the complementary Weibull distribution, was significantly reduced by 25% to 72.7% compared with that in a single break. Due to the voltage-sharing effect in the double-break VCB, scatters in prestrike gaps of each VI in a double break was smaller than that in a single break. However, without the sharing-voltage effect, d50 of the low-voltage side in the double break was 65% higher than that of the same VI in the single break, which could be caused by the asynchronous property of mechanical actuators, the difference of the inherent prestrike characteristics of each VI and the unequal voltage-sharing ratio of VIs.

STUDIES OF SUPERHEAVY ELEMENTS AT SHIP

2007 ◽  
Vol 16 (04) ◽  
pp. 937-947
Author(s):  
S. HOFMANN ◽  
D. ACKERMANN ◽  
S. ANTALIC ◽  
H. G. BURKHARD ◽  
V. F. COMAS ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Experimental Work ◽  
Spontaneous Fission ◽  
Measured Data ◽  
Superheavy Elements ◽  
Fission Event

An overview of present experimental investigation of superheavy elements is given. The data are compared with theoretical descriptions. Results are reported from an experiment to confirm production of element 112 isotopes in irradiation of 238 UF 4 with 48 Ca . One spontaneous fission event was measured, which agrees with three events of previously measured data which had been assigned to the decay of 283112. However, more experimental work is needed in order to obtain an independent and unambiguous confirmation of previous results.

A Numerical and Experimental Investigation of Low-conductivity Unglazed, Transpired Solar Air Heaters

2005 ◽  
Vol 127 (1) ◽  
pp. 153-155 ◽  
Author(s):  
Keith Gawlik ◽  
Craig Christensen ◽  
Charles Kutscher
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Experimental Investigation ◽  
Experimental Work ◽  
Experimental Results ◽  
Flow Conditions ◽  
Numerical Work ◽  
Plate Geometry ◽  
Modeling Flow ◽  
Good Agreement

The performance of low-conductivity unglazed, transpired solar collectors was determined numerically and experimentally. The numerical work consisted of modeling flow conditions, plate geometries, and plate conductivities with modified commercial computational fluid dynamics software, and the experimental work compared the performance of two plate geometries made with high and low conductivity materials under a variety of flow conditions. Good agreement was found between the numerical and experimental results. The results showed that for practical low-conductivity materials, performance differed little from the equivalent plate geometry in high-conductivity material.

scholarly journals An Experimental Investigation of the Trim Effect on the Behaviour of a Containership in Shallow Water

2019 ◽  
Author(s):  
Khaled Elsherbiny ◽  
Tahsin Tezdogan ◽  
Mohamed Kotb ◽  
Atilla Incecik ◽  
Sandy Day
Keyword(s):  
Experimental Investigation ◽  
Water Depth ◽  
Experimental Work ◽  
Water Resistance ◽  
Suez Canal ◽  
Shallow Waters ◽  
Container Ship ◽  
Ship Model ◽  
New Suez Canal ◽  
The University

Abstract A new division of the Suez Canal in Egypt, termed the New Suez Canal, was opened for international navigation in August 2015. It is therefore important to ensure the safety of ships navigating this new section of the canal. Measures to avoid grounding and/or drifting to the canal banks are necessary. Additionally, accurate prediction data for ship squat and under keel clearance is crucial. This paper presents the results of experimental work carried out at the Kelvin Hydrodynamic Laboratory at the University of Strathclyde, Glasgow, to study the effect of trim on containership sailing characteristics in shallow waters using Kriso Container Ship (KCS) model. A series of model tests were conducted to measure the resistance, sinkage variations with speed, water depth and loading conditions under different trimming angles at 1:75 scale. The objective of this work is to examine the range of ship trim for safe and efficient sailing in restricted water in both depth and width. The study also aimed to provide data to be used in validating numerical computations to be carried on the same type of vessel to detect the best trim angle for ships during sailing in restricted waters to reduce resistance and therefore fuel consumption. For depth Froude numbers higher than 0.4, the results show that the ship model sinkage is less for aft trim than for level trim or forward trim. Concurrently, it can be observed that there is less water resistance for aft trim than for forward trim, albeit level trim shows the least resistance. The test was conducted for one value of model draft which was 0.144 m. Side bank effect were also examined.

Design of built-up steel beam-columns composed of two-channel sections

2020 ◽  
Author(s):  
George Iskander ◽  
Emam Soliman ◽  
Ezzeldin Yazeed Sayed-Ahmed
Keyword(s):  
Experimental Investigation ◽  
Numerical Model ◽  
Experimental Work ◽  
Parametric Study ◽  
Design Method ◽  
Steel Beam ◽  
Fe Model ◽  
Beam Columns ◽  
Initial Imperfections ◽  
Good Agreement

Built-up columns composed of two chords present an ideal design for long columns subject to high straining actions. The objective of this paper is to investigate the capacity of built-up columns composed of two-channel sections subjected to eccentric loading and propose a design method for them. A nonlinear numerical FE model is developed for these columns and verified against experimental investigation available from literature; the model includes both the geometric and materials nonlinearities along with the effect of initial imperfections. The model is used to perform a parametric study to investigate the effect of different factors on the built-up columns’ capacity. The results of the parametric study are also used to propose a design method for these columns. A limited experimental investigation is performed on two eccentrically loaded built-up columns, the results of experimental work showed good agreement with the numerical model results and the proposed design method.

Intake shape and boundary-related considerations in the operation and design of storm-sewer drop structures

2009 ◽  
Vol 36 (11) ◽  
pp. 1825-1834 ◽  
Author(s):  
A. Auckland ◽  
I. Nistor ◽  
R. Townsend
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Water Intake ◽  
Experimental Work ◽  
Vortex Formation ◽  
Design Guidelines ◽  
Hydraulic Efficiency ◽  
Local Shape ◽  
Geometrical Characteristics ◽  
Storm Sewer

This paper presents the results of an experimental investigation into the hydraulic efficiency of a vertically oriented water intake. Under low submergence conditions, the operation of such an intake is affected significantly by the formation of surface vortices, which result in significant flow reduction and the downstream entrainment of air and swirl. The experimental work considered the fact that vortex formation is governed by the geometrical characteristics of the intake, including the diameter, local shape, submergence, surrounding boundary, etc, and the velocity distribution in the approaching flow. Therefore, an experimental study was conducted to investigate the influence that the local shape and the proximity to nearby boundaries have on the hydraulic performance of a vertical water intake. The results of this experimental investigation will hopefully lead to a better understanding of the phenomena governing the flow in such structures and to the elaboration of improved engineering design guidelines.

scholarly journals II. An experimental investigation of the nerve roots which enter into the formation of the lumbo-sacral plexus of macacus rhesus

1893 ◽  
Vol 53 (321-325) ◽  
pp. 459-462 ◽  
Keyword(s):  
Experimental Investigation ◽  
Sciatic Nerve ◽  
Brachial Plexus ◽  
Experimental Work ◽  
Nerve Root ◽  
Present Communication ◽  
Sacral Plexus ◽  
Nerve Roots ◽  
Sacral Nerve Root ◽  
History Of

As the history of this subject was fully detailed in a former paper by the author on the brachial plexus of the Dog, only such experimental work as has been done in connexion with the lumbo-sacral plexus is reviewed in the present communication. In dealing with the anatomy of the Monkey it is shown that the class of plexus most commonly met with has many features in common with that described by Sherrington as the “prefixed” class of plexus; while of the variations met with that which occurred most frequently has many points in common with the class of plexus designated “postfixed” by that observer; but that there is one very notable difference between the last two, as in no instance was the 2nd sacral nerve root found to contribute a branch to the sciatic nerve, a contribution which Sherrington describes in this class of plexus.

scholarly journals Studies upon catalytic combustion.—Part III. The influence of steam upon the catalytic combustion of carbonic oxide

1926 ◽  
Vol 112 (762) ◽  
pp. 474-499 ◽  
Keyword(s):  
Experimental Investigation ◽  
Experimental Work ◽  
Catalytic Combustion ◽  
Imperial College ◽  
Porous Surface ◽  
Lehigh University ◽  
Utmost Care ◽  
The Subject ◽  
The University ◽  
Specific Influence

In connection with the researches upon catalytic combustion conducted in my laboratories for some years past, a great deal of attention has been paid to the experimental investigation of the important question of whether or no the presence of moisture has any specific influence upon the catalytic combustion of carbonic oxide. The present paper embodies the principal results of our investigations up to date. They were begun in 1908 at the University of Leeds, in collaboration with the two Gas Research Fellows—Mr. A. Forshaw, M. Sc., and Dr. H. Hartley—as well as with Mr. A. Appleyard, B. Sc., and have been completed at the Imperial College of Science and Technology, London, with the collaboration of the late W. A. Haward, M. Sc., Mr. S. Robson, B. Sc., A. Whitaker, B. Sc., and Prof. D. S. Chamberlin, of Lehigh University, U. S. A., who recently spent a "sabbatical year" working with us. The difficult nature of the experimental work involved operations demanding the utmost care, great attention to details, and unusual skill on the part of my collaborators. The surfaces experimented with were porous porcelain, the oxides of copper and nickel, gold and silver, And, in view of the importance of the results in connection with the theoretical aspects of the subject, many independent repetitions of the experiments were made at various times to ensure their complete confirmation. In the case of a very porous surface, such as fireclay or porous porcelain, it was ultimately found necessary to extend a given experiment uninterruptedly day and night over three months, in order to ensure complete dryness of the system. Indeed, not until the later stages of the research was it possible to view correctly and reconcile all the results.

An Experimental Investigation Into the Effect of Lubricant on the Local Film Thickness of Artificial Roughness Features

2008 ◽  
Author(s):  
M. D. Furtuna ◽  
R. P. Glovnea
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Experimental Work ◽  
Good Deal ◽  
Viscosity Coefficient ◽  
Point Of View ◽  
Experimental Point ◽  
Artificial Roughness ◽  
Random Roughness ◽  
Interferometry Method

The lubrication of rough surfaces has been a focus of researchers in the field for many years now. A good deal of work has been carried out either on the experimental or on the theoretical sides of the research. From the experimental point of view it is obviously more convenient to study the lubrication of artificial roughness features such as ridges, bumps or dents rather than real, random roughness. The advantage of model roughness features is that they are well individualized, located, and characterized, thus a comparison of the surfaces geometry inside and outside an elastohydrodynamic contact can be made. The studies carried out so far have focused on the effect of the geometry of the features and that of the entrainment speed. No detailed experimental work on the effect of the lubricant properties on the behavior of the EHD films has been performed, to the authors’ knowledge. The present study uses the optical interferometry method to measure the EHD film thickness between a flat disc and a ball on which artificial ridges have been sputtered. Two lubricants, with different viscosity and pressure/viscosity coefficient are used in a range of pressures and entrainment speeds.

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