scholarly journals The Solar Irradiation Record in Lunar Dust Grains

1972 ◽  
Vol 47 ◽  
pp. 298-308
Author(s):  
J. Borg ◽  
B. Vassent
Keyword(s):  
External Surface ◽  
Lunar Soil ◽  
Solar Irradiation ◽  
Solar Cosmic Rays ◽  
Core Tube ◽  
Transmission Microscopy ◽  
Lunar Dust ◽  
Electron Microscopies ◽  
The Core ◽  
Different Depths

Comparative studies of the distribution of latent and etched tracks in lunar grains from five different size fractions of three lunar fine samples and of six lunar dust samples taken at different depths in core tube 12028 have been performed by using transmission and scanning electron microscopies. Two very different sets of etching conditions were used: a slight etching was applied for transmission microscopy but a much stronger etching was used for scanning microscopy. We observed: (1) a definite stratigraphy in the core tube, both in the latent and etched track distributions; (2) striking differences between the densities of the latent and slightly etched tracks (≥ 1010 tracks cm−2) and those of the strongly etched tracks, ranging from ⋍ 108 to 5.109 tracks cm−2; (3) a lack of correlation between the grain size and the density of strongly etched tracks observed on the external surface of grains from sample 12032; (4) no variation of the density of the tracks with the depth inside a grain. Some implications of the present results concerning the ancient low energy solar cosmic rays and the fabric of the lunar soil will be briefly discussed.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

scholarly journals Designing a Cartridge Winder with Electronic Control

2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900 ◽  
Author(s):  
Pragnya Sanjiv Kanade ◽  
Someshwar S. Bhattacharya
Keyword(s):  
Laboratory Model ◽  
Electronic Control ◽  
Core Tube ◽  
Feed Material ◽  
The Core ◽  
Dyeing Process ◽  
Recent Trends ◽  
Precision System ◽  
A Chain ◽  
Filter Cartridge

There are number of winding machines in the market based on either the Random, Precision, or Step Precision winding system. Filtration application requires a uniform lay of yarn or its performance may be affected, hence, for the aforesaid purpose, the precision system would be more apt. Recent trends show an increased use of electronics in all applications, textiles being no exception. The aim of the present work was to develop a filter cartridge winder (laboratory model) based on the precision winding system, controlled electronically. The novelty of this machine lies in the fact that it makes use of a chain to reciprocate the guide mounted on it, unlike the majority of commercial filter winders, which make use of scroll cams to traverse the yarn. Filter winders are specialized winders that produce cartridges in standard sizes of 10”, 20”, 30″ and up to 70”. Thus a cartridge winder is quite different from the usual winding machines not only in terms of its traverse length and feed material but also because of the core tube which has to be perforated just as one required for a dyeing process.

Research on Mass Concrete Construction Techonogy of Raft Foundation of Hongyun Building

2013 ◽  
Vol 690-693 ◽  
pp. 709-713 ◽  
Author(s):  
Su Hua Yin ◽  
Yuan Huang ◽  
Ying Hui Yuan
Keyword(s):  
Temperature Control ◽  
Mass Concrete ◽  
Construction Technology ◽  
Concrete Construction ◽  
Core Tube ◽  
The Core ◽  
Raft Foundation ◽  
Concrete Base

The foundation of A tower of Hongyun building is made of raft board foundation which is 4200mm in the thickness and 3500mm beside side of the core tube. It is researched that the raft foundation mass concrete construction technology is expatiated from temperature and cracks of the raft foundation and the temperature control and monitoring of the concrete base slab construction and concrete curing.

The Solar Irradiation Record in Lunar Dust Grains

The Moon ◽  
1972 ◽  
pp. 298-308 ◽  
Author(s):  
J. Borg ◽  
B. Vassent
Keyword(s):  
Solar Irradiation ◽  
Dust Grains ◽  
Lunar Dust

Mechanical behaviours of monitoring sleeved members with rigid ends at both core tube sides

2021 ◽  
Author(s):  
Wudang Ying ◽  
Changgen Deng ◽  
Chenhui Zhang
Keyword(s):  
Finite Element ◽  
Spatial Structure ◽  
Finite Element Model ◽  
Bearing Capacity ◽  
Slenderness Ratio ◽  
Element Model ◽  
Core Tube ◽  
The Core ◽  
Global Buckling ◽  
Mechanical Behaviours

<p>The monitoring sleeved members (MSMs) are considered with light weight, excellent load-bearing capacity, superior ductility, and can be applied in long span spatial structure to monitor the capacity of the spatial structure. This paper mainly focuses on presenting the mechanical behaviours of the MSMs based on the full-range finite element analysis. The finite element model was developed to simulate the mechanical behaviors of the MSMs, which was verified by a specimen test. Based on the verified finite element model, parametric studies were carried out to investigate the influence of the core protrusion lp, the core slenderness ratio λi, the flexural rigidity ratio β, and the gap δg between core tube and restraining tube on the mechanical behaviours of the MSMs. It is concluded that (1) lp determines the control range of the restraining tube to the core tube. Local buckling of the MSMs with lp/l≤0.0406 occurs at a relatively small axial deformation. The ultimate bearing capacity of the MSMs with lp/l≤0.0406 is generally less than that of the MSM with lp/l&gt;0.0406; (2) λi is a sensitive parameter influencing the failure mode. The smaller the core slenderness ratio λi, the less likely global buckling will occur; (3) β guarantees the control effect of the restraining tube on the core tube. β≥8.349 is needed to avoid global buckling; (4) a proper δg determining the alert moment for contact is indispensable to monitor contact status of MSMs, but it has no effect on the failure mode.</p>

Reconstructing Lake History Changes from Zooplankton Subfossil in the Sediment of Wuliangsuhai Lake, China

2011 ◽  
Vol 183-185 ◽  
pp. 710-714
Author(s):  
Zhen Ying Liu ◽  
Ya Wei Li ◽  
Zhao Hui Jin ◽  
Xiao Li Wang
Keyword(s):  
Shallow Lake ◽  
Sediment Samples ◽  
The Core ◽  
Large Shallow Lake ◽  
Key Factor ◽  
Different Depths ◽  
High Predation ◽  
Lake History ◽  
Anthropogenic Pollutant ◽  
High Predation Pressure

The sediment samples of zooplankton subfossil at different depths were collected from a large shallow lake Wuliangsuhai Lake, China, in order to reconstruct lake past changes. The lake began to switch to eutrophication gradually in the middle 1980s, creating a sediment discontinuity layer (about 32.5 cm depth) that can be visually used to separate sediments derived from plankton and macrophyte. Inferences about the timing and trajectory of eutrophication were made using sediment zooplankton subfossil reconstruction. The changes in composition of the zooplankton fragments were rather gradual up the core, whereas the total numbers of fragments show the most marked changes from 32.5 cm to present. Changes in the composition of zooplankton fragments (in 32.5 cm depth) show a gradual shift from a “pelagic community” dominated by B. longirostris, reflecting clearwater conditions with high predation pressure, to a more “benthic” community, dominated by plant associated Chydorids. The results suggest that it is possible to reconstruct past eutrophication trends of the lake by using zooplankton subfossil, and that anthropogenic pollutant loading is the key factor in the eutrophication of Lake Wuliangsuhai.

Turbulent Flow in an Annulus

1967 ◽  
Vol 89 (1) ◽  
pp. 25-31 ◽  
Author(s):  
S. Levy
Keyword(s):  
Turbulent Flow ◽  
Tube Wall ◽  
Eddy Diffusivity ◽  
Test Results ◽  
Core Tube ◽  
The Core ◽  
Roughened Surface ◽  
Shear Mixing ◽  
Fully Developed Turbulent Flow ◽  
Good Agreement

Equations describing fully developed turbulent flow in an annulus are derived. They are based upon Reichardt’s expression for the eddy diffusivity of momentum, and they assume that the velocity profiles starting from the core tube wall and the outer tube wall have the same velocity and eddy diffusivity at the plane of zero shear. The predicted location of the plane of zero shear, mixing length, eddy diffusivity, velocity distribution, and friction factor are compared to available data and are found to give good agreement with the test results. Potential extension of the proposed method to more complex geometries is illustrated by considering the case of flow in an annulus with one artificially roughened surface.

Seismic Assessment of Out-of-Code High-Rise Building Using Dynamic Nonlinear Analysis

2011 ◽  
Vol 378-379 ◽  
pp. 292-296
Author(s):  
Xue Shu Wu ◽  
Wan Li Xue ◽  
Guo Rui ◽  
Xu Qian Zhao ◽  
Gu Li
Keyword(s):  
Nonlinear Analysis ◽  
Kinematic Hardening ◽  
Nonlinear Dynamic Analysis ◽  
Shear Walls ◽  
Element Model ◽  
Core Tube ◽  
Shell Elements ◽  
High Rise ◽  
The Core ◽  
High Rise Building

Seismic response of a high-rise building under rare earthquake is numerically investigated in the paper. The Height of the building is 266m, which goes beyond the limit of 150m in Chinese standard, so nonlinear analysis should be performed to investigate its elasto-plastic behaviors under severe earthquake excitations. In the finite-element model for analysis, beam-column members of the structure are simulated by beam elements, while the core tube is simulated by shell elements. The concrete damage plasticity model is used for concrete members, while the kinematic hardening rule is defined for steel beam-column members. Four sets of earthquake wave, including 3 sets of strong earthquake records and 1 set of artificial wave, are adopted in the analysis. The analysis results show that, under severe earthquakes, steel frame members and steel truss members in the strengthened floors keep elastic. Severe damages are detected in almost all coupling beams in the core tube, as well as shear-walls near strengthened stories, where lateral stiffness would decrease seriously. Through the investigation, it is also found that the largest story drift is less than the maximum allowable value in the Chinese code for seismic design of buildings. So it is concluded that the high-rise building will not collapse when the place is subjected to severe earthquakes. Besides, some design suggestions are proposed according to nonlinear dynamic analysis in the paper.

scholarly journals Contactless Detection of Natural Bending Frequencies using Embedded Metallic-Glass Ribbons inside Plastic Beams made of 3-D Printing

2020 ◽  
Vol 03 (02) ◽  
pp. 1-1
Author(s):  
imitris Kouzoudis ◽  
◽  
Georgios Samourgkanidis ◽  
Christos I. Tapeinos ◽  
◽  
...  
Keyword(s):  
Metallic Glass ◽  
Magnetic State ◽  
External Surface ◽  
Current Work ◽  
Cantilever Beams ◽  
Proof Of Concept ◽  
Mechanical State ◽  
Bending Mode ◽  
Different Depths ◽  
Unique Signature

In the current work, to identify the bending mode harmonics, 30 microns thin magnetoelastic ribbons made of metallic glass are embedded inside 6 mm thick PLA plastic cantilever beams made by 3-D printing. This is possible because the ribbons are of magnetoelastic nature and thus change their mechanical state inducing a corresponding change in their magnetic state. The ribbons are placed at four different depths, starting with zero depth at the beam’s external surface all the way inside to the beam’s mid-plane. This technique is capable of detecting seven harmonics, and remarkably, these frequencies remain the same within a marginal error of 1% for all the depths. The amplitude of the modes drops with the increase in depth but is still strong enough, except at the midplane, to be used as a sensing signal. The harmonics spectrum is the unique signature of the structure’s state; this is a proof of concept that in a contactless fashion, the embedded ribbons provide useful information about the mechanical health of a structure.

scholarly journals Design, Manufacture, and Operation of a Core Barrel for the Iceland Deep Drilling Project (IDDP)

2010 ◽  
Vol 10 ◽  
pp. 40-45 ◽  
Author(s):  
A. C. Skinner ◽  
P. Bowers ◽  
S. Þórhallsson ◽  
G. Ómar Friðleifsson ◽  
H. Guðmundsson
Keyword(s):  
Drill Pipe ◽  
Depth Interval ◽  
Data Logger ◽  
Deep Drilling ◽  
Core Tube ◽  
The Core ◽  
Core Recovery ◽  
Short Period ◽  
Design Characteristics ◽  
Drilling Project

The science program of the Iceland Deep Drilling Project (IDDP) requires as much core as possible in the transition zone to supercritical and inside the supercritical zone (>374°C), in the depth interval 2400–4500 m. The spot coring system selected has a 7 1/4" (184.15 mm) OD at 10 m length and collects a 4" (101.6 mm) diameter core using an 8 1/2" (215.9 mm) OD core bit. It incorporates design characteristics, materials, clearances and bearings compatible with operation of the core barrel at temperatures as high as 600°C. Special attention was given to the volume of flushing which could be applied to the core barrel and through the bit while running in and out of the borehole and while coring. In November 2008 a successful spot coring test using the new core barrel was performed at 2800 m depth in the production well RN-17 B at Reykjanes, Iceland, where the formation temperature is 322°C. A 9.3-m hydrothermally altered hyaloclastite breccia was cored with 100% core recovery, in spite of it being highly fractured. A core tube data logger was also designed and placed inside the inner barrel to monitor the effectiveness of cooling. The temperature could be maintained at 100°C while coring, but it reached 170°C for a very short period while tripping in. The effective cooling is attributed to the high flush design and a top drive being employed, which allows circulation while tripping in or out, except for the very short time when a new drill pipe connection is being made. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.10.05.2010" target="_blank">10.2204/iodp.sd.10.05.2010</a>

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