The Efficiency of Adaptive Structures in the Nymph of Rhithrogena Semicolorata (Curtis) (Ephemeroptera)

A. M. STUART

doi:10.1242/jeb.35.1.27

The Efficiency of Adaptive Structures in the Nymph of Rhithrogena Semicolorata (Curtis) (Ephemeroptera)

Journal of Experimental Biology ◽

10.1242/jeb.35.1.27 ◽

1958 ◽

Vol 35 (1) ◽

pp. 27-38

Author(s):

A. M. STUART

Keyword(s):

Adaptive Structures ◽

A Current ◽

Rhithrogena Semicolorata

1. The current-resisting powers of Rhithrogena semicolorata Curtis have been investigated and measured, and compared with those of Ecdyonurus sp. 2. The part played by the gills as organs of adhesion is considered, and they are found to contribute little to the current-resisting powers of the nymph. The claws are regarded as being of more importance to the animal in clinging than the gills. 3. The dorso-ventral flattening of the animal is considered to be a crevice-seeking adaptation, and not a current-resisting one.

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Resolving Crystallites in Zirconium Oxide Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062610 ◽

1969 ◽

Vol 27 ◽

pp. 140-141

Author(s):

R.A. Ploc

Keyword(s):

Electron Microscope ◽

Inelastic Scattering ◽

Zirconium Oxide ◽

Oxide Films ◽

Optic Axis ◽

Objective Lens ◽

Microscope Objective ◽

Linear Optic ◽

A Current ◽

Microscope Objective Lens

The optic axis of an electron microscope objective lens is usually assumed to be straight and co-linear with the mechanical center. No reason exists to assume such perfection and, indeed, simple reasoning suggests that it is a complicated curve. A current centered objective lens with a non-linear optic axis when used in conjunction with other lenses, leads to serious image errors if the nature of the specimen is such as to produce intense inelastic scattering.

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Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069272 ◽

1970 ◽

Vol 28 ◽

pp. 456-457

Author(s):

L. E. Murr ◽

G. Wong

Keyword(s):

Single Crystal ◽

High Vacuum ◽

Ultra High Vacuum ◽

High Rate ◽

Flash Evaporation ◽

Optimum Load ◽

Single Crystal Films ◽

Crystal Films ◽

A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

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Novel magneto-optical recording materials: Bi-substituted garnet films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088191 ◽

1991 ◽

Vol 49 ◽

pp. 776-777

Author(s):

Takao Suzuki ◽

Hossein Nuri

Keyword(s):

Grain Size ◽

Amorphous Film ◽

Nitrogen Atmosphere ◽

Optical Recording ◽

Garnet Film ◽

Media Noise ◽

Garnet Films ◽

Order Of Magnitude ◽

A New Technique ◽

A Current

For future high density magneto-optical recording materials, a Bi-substituted garnet film ((BiDy)3(FeGa)5O12) is an attractive candidate since it has strong magneto-optic effect at short wavelengths less than 600 nm. The signal in read back performance at 500 nm using a garnet film can be an order of magnitude higher than a current rare earth-transition metal amorphous film. However, the granularity and surface roughness of such crystalline garnet films are the key to control for minimizing media noise.We have demonstrated a new technique to fabricate a garnet film which has much smaller grain size and smoother surfaces than those annealed in a conventional oven. This method employs a high ramp-up rate annealing (Γ = 50 ~ 100 C/s) in nitrogen atmosphere. Fig.1 shows a typical microstruture of a Bi-susbtituted garnet film deposited by r.f. sputtering and then subsequently crystallized by a rapid thermal annealing technique at Γ = 50 C/s at 650 °C for 2 min. The structure is a single phase of garnet, and a grain size is about 300A.

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Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164155 ◽

1996 ◽

Vol 54 ◽

pp. 338-339

Author(s):

I-Fei Tsu ◽

D.L. Kaiser ◽

S.E. Babcock

Keyword(s):

Grain Boundary ◽

Critical Current Density ◽

Critical Current ◽

Current Density ◽

Electromagnetic Properties ◽

Length Scale ◽

Density Values ◽

Current Densities ◽

Applied Fields ◽

A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

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Rem Study of Current Effect on the Structure of Clean Si(111) Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100180288 ◽

1990 ◽

Vol 48 (1) ◽

pp. 306-307

Author(s):

A. Yamanaka ◽

H. Ohse ◽

K. Yagi

Keyword(s):

The Other ◽

Current Direction ◽

Clean Surface ◽

Current Effect ◽

Atomic Steps ◽

Step Bunching ◽

Terrace Width ◽

Step Down ◽

A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

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A highly stable CoMo2S4/Ni3S2 heterojunction electrocatalyst for efficient hydrogen evolution

Chemical Communications ◽

10.1039/d0cc06972h ◽

2021 ◽

Author(s):

Minmin Wang ◽

Mengke Zhang ◽

Wenwu Song ◽

Weiting Zhong ◽

Xunyue Wang ◽

...

Keyword(s):

Hydrogen Evolution ◽

Current Density ◽

A Current

A CoMo2S4/Ni3S2 heterojunction is prepared with an overpotential of only 51 mV to drive a current density of 10 mA cm−2 in 1 M KOH solution and ∼100% of the potential remains in the ∼50 h chronopotentiometric curve at 10 mA cm−2.

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Current Trends in the Training and Utilization of Paraprofessionals in Speech and Language Programs

Language Speech and Hearing Services in Schools ◽

10.1044/0161-1461.2202.51 ◽

1991 ◽

Vol 22 (2) ◽

pp. 51-59 ◽

Cited By ~ 6

Author(s):

Kathy L. Coufal ◽

Allen L. Steckelberg ◽

Stanley F. Vasa

Keyword(s):

Selection Criteria ◽

Job Descriptions ◽

Paraprofessional Training ◽

Language Programs ◽

Program Administrators ◽

Current Trends ◽

Training And Supervision ◽

Communicative Disorders ◽

Supervision Practices ◽

A Current

Administrators of programs for children with communicative disorders in 11 midwestern states were surveyed to assess trends in the training and utilization of paraprofessionals. Topics included: (a) current trends in employment, (b) paraprofessional training, (c) use of ASHA and state guidelines, and (d) district policies for supervision. Selection criteria, use of job descriptions, training programs, and supervision practices and policies were examined. Results indicate that paraprofessionals are used but that standards for training and supervision are not consistently applied across all programs. Program administrators report minimal training for supervising professionals.

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