Surface Subsidence Caused by Trench Excavation under Construction Machinery Load

A magnetic spectrometer to be attached to the Johns Hopkins S. T. E. M. is under construction. Its main purpose will be to investigate electron interactions with biological molecules in the energy range of 40 KeV to 100 KeV. The spectrometer is of the type described by Kerwin and by Crewe Its magnetic pole boundary is given by the equationwhere R is the electron curvature radius. In our case, R = 15 cm. The electron beam will be deflected by an angle of 90°. The distance between the electron source and the pole boundary will be 30 cm. A linear fringe field will be generated by a quadrupole field arrangement. This is accomplished by a grounded mirror plate and a 45° taper of the magnetic pole.

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Radiation Damage Studies with the HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096655 ◽

1972 ◽

Vol 30 ◽

pp. 680-681

Author(s):

J. J. Laidler ◽

B. Mastel

Keyword(s):

Radiation Damage ◽

Stainless Steels ◽

Volume Expansion ◽

Austenitic Stainless Steels ◽

Test Facility ◽

Fast Breeder Reactors ◽

Breeder Reactors ◽

Under Construction ◽

Development Laboratory ◽

Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

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Description of a New High Resolution Scanning Transmission EM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100095340 ◽

1972 ◽

Vol 30 ◽

pp. 418-419

Author(s):

Michael Beer ◽

J. W. Wiggins ◽

David Woodruff ◽

Jon Zubin

Keyword(s):

High Resolution ◽

Field Emission ◽

Energy Dispersive Spectrometer ◽

Scanning Transmission Electron Microscope ◽

Objective Lens ◽

Condenser Lens ◽

Transmission Electron ◽

Pattern Size ◽

Scanning Transmission ◽

Under Construction

A high resolution scanning transmission electron microscope of the type developed by A. V. Crewe is under construction in this laboratory. The basic design is completed and construction is under way with completion expected by the end of this year.The optical column of the microscope will consist of a field emission electron source, an accelerating lens, condenser lens, objective lens, diffraction lens, an energy dispersive spectrometer, and three electron detectors. For any accelerating voltage the condenser lens function to provide a parallel beam at the entrance of the objective lens. The diffraction lens is weak and its current will be controlled by the objective lens current to give an electron diffraction pattern size which is independent of small changes in the objective lens current made to achieve focus at the specimen. The objective lens demagnifies the image of the field emission source so that its Gaussian size is small compared to the aberration limit.

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Cochlea Under Construction

ASHA Leader ◽

10.1044/leader.ae.16092011.40 ◽

2011 ◽

Vol 16 (9) ◽

pp. 40-41

Author(s):

Jessica J. Messersmith

Keyword(s):

Under Construction

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Participation and learning of the Xakriaba boys, between the hunts, the hoe and the school: Tensions of a debate under construction

PsycEXTRA Dataset ◽

10.1037/e570782013-114 ◽

2013 ◽

Author(s):

Rogerio Correia da Silva

Keyword(s):

Under Construction

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The House That Google Built? Power and Progress under Construction 4.0

Construction Research Congress 2020 ◽

10.1061/9780784482865.062 ◽

2020 ◽

Author(s):

Fred Sherratt ◽

Ruth Dowsett ◽

Simon Sherratt

Keyword(s):

Under Construction

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‘The well-known, old, but still unbeaten track’: Women Poets and Irish Periodical Culture in the Mid-Twentieth Century

Irish University Review ◽

10.3366/iur.2012.0007 ◽

2012 ◽

Vol 42 (1) ◽

pp. 32-52 ◽

Cited By ~ 3

Author(s):

Anne Mulhall

Keyword(s):

Twentieth Century ◽

Literary Culture ◽

Woman Writer ◽

Double Bind ◽

Women Poets ◽

Substantial Body ◽

Growing Body ◽

Critical Attention ◽

Irish Women ◽

Under Construction

While neglected Irish male poets of the mid century have seen some recuperation in recent decades, the work of Irish women poets still languishes in obscurity. A growing body of scholarship has identified the need to bring critical attention to bear on this substantial body of work. In this essay I explore the positioning of Irish women poets in mid-century periodical culture, to flesh out the ways in which the terms of this ‘forgetting’ are already established within the overwhelmingly masculinist homosocial suppositions and idioms that characterized contemporary debates about the proper lineage and aesthetic norms for the national literary culture that was then under construction. Within the terms set by those debates, the woman writer was caught in the double bind that afflicted any woman wishing to engage in a public, politicized forum in post-revolutionary Ireland. While women poets engage in sporadic or oblique terms with such literary and cultural debates, more often their voices are absent from these dominant discourses – the logic of this absence has continued in the occlusion of these women poets from the national poetic canon.

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ANALYSIS OF THE GENERAL EQUATIONS OF THE TRANSVERSE VIBRATION OF A PIECEWISE UNIFORM VISCOELASTIC PLATE

Computational nanotechnology ◽

10.33693/2313-223x-2020-7-3-52-56 ◽

2020 ◽

Vol 7 (3) ◽

pp. 52-56

Author(s):

MMATMATISA JALILOV ◽

◽

RUSTAM RAKHIMOV ◽

Keyword(s):

Cross Section ◽

Transverse Vibration ◽

Three Dimensional ◽

Viscoelastic Plate ◽

Constant Thickness ◽

Regional Problem ◽

Rigid Contact ◽

Under Construction ◽

Derivatives Of ◽

Theoretical Results

This article discusses the analysis of the general equations of the transverse vibration of a piecewise homogeneous viscoelastic plate obtained in the “Oscillation of inlayer plates of constant thickness” [1]. In the present work on the basis of a mathematical method, the approached theory of fluctuation of the two-layer plates, based on plate consideration as three dimensional body, on exact statement of a three dimensional mathematical regional problem of fluctuation is stood at the external efforts causing cross-section fluctuations. The general equations of fluctuations of piecewise homogeneous viscoelastic plates of the constant thickness, described in work [1], are difficult on structure and contain derivatives of any order on coordinates x, y and time t and consequently are not suitable for the decision of applied problems and carrying out of engineering calculations. For the decision of applied problems instead of the general equations it is expedient to use confidants who include this or that final order on derivatives. The classical equations of cross-section fluctuation of a plate contain derivatives not above 4th order, and for piecewise homogeneous or two-layer plates the elementary approached equation of fluctuation is the equation of the sixth order. On the basis of the analytical decision of a problem the general and approached decisions of a problem are under construction, are deduced the equation of fluctuation of piecewise homogeneous two-layer plates taking into account rigid contact on border between layers, and also taking into account mechanical and rheological properties of a material of a plate. The received theoretical results for the decision of dynamic problems of cross-section fluctuation of piecewise homogeneous two-layer plates of a constant thickness taking into account viscous properties of their material allow to count more precisely the is intense-deformed status of plates at non-stationary external loadings.

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Impact Assessment of Dynamic Characteristics on the Hydraulic Driven Machinery Operation

Mechanical Engineering and Computer Science ◽

10.24108/0418.0001354 ◽

2018 ◽

pp. 1-12

Author(s):

A. D. Terenteva

Keyword(s):

Dynamic Error ◽

Total Error ◽

Soil Layer ◽

Hydraulic Drive ◽

Hydraulic Cylinder ◽

Working Mechanism ◽

Automated Control ◽

Vertical Coordinate ◽

Construction Machinery ◽

The Difference

In civil engineering in Russia, trenching for utilities is currently under digging. To perform such works, it is necessary to use high-precision construction machinery, because inaccurate performance of works can lead to the break down of existing utilities, thereby affecting the residents of nearby houses and demanding the additional works for renewal.The most universal labour saver to perform construction works is hydraulic driven single-bucket excavators, which provide up to 38% of works. Therefore, to improve technical characteristics that affect the accuracy of the work performed is an important task.High requirements for the performance of works are defined by existing construction regulations: an allowable soil layer to remain is at most 0.05 m. To fulfil such requirements, an exact assessment of the working mechanism position and a trench profile is necessary.Examination of a manually operated digging process shows that an operator provides operations untimely, however an automated control system can solve this problem. Dynamic phenomena in the working mechanism have the greatest impact on the accuracy of the works performed.To assess the bucket digging edge position accuracy, a mathematical model of the working mechanism has been created. Based on the cycle scheme of the working process, the excessive displacements of the hydraulic cylinder rods under the load are taken into account. By the end of the cycle, the difference between the specified and obtained positions along the vertical coordinate has been 0.0892 m.A dynamic error of the hydraulic drive system of the working mechanism is considered as a sum of the error due to excessive displacements of the hydraulic cylinder rods and the error due to delay of the hydraulic drive, with the latter being calculated for the average time of delay taking into account the data available in the literature. The total error of the bucket digging edge position of the working mechanism is 0.1176 m, which is 2 times more than the value of 0.05 mConformity of all the links with specification requirements does not guarantee compliance with the required displacement accuracy of the bucket digging edge, and, thus, the soil layer to remain in the base of the trench can exceed the regulated value of 0.05 m.

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