Correlation between dislocation, grain boundary and interface of duplex SS in stress corrosion cracking(SCC)

1990 ◽  
Vol 48 (4) ◽  
pp. 928-929
Author(s):  
Wang Zheng-fang ◽  
Z.F. Wang
Keyword(s):  
Stainless Steel ◽  
Thermal Cycle ◽  
Secondary Phase ◽  
Corrosion Cracking ◽  
Coarse Grained ◽  
Test Environment ◽  
Fine Grained ◽  
Evaluation Test ◽  
Welding Thermal Cycle ◽  
Micro Analysis

The main purpose of this study highlights on the evaluation of chloride SCC resistance of the material,duplex stainless steel,OOCr18Ni5Mo3Si2 (18-5Mo) and its welded coarse grained zone(CGZ).18-5Mo is a dual phases (A+F) stainless steel with yield strength:512N/mm2 .The proportion of secondary Phase(A phase) accounts for 30-35% of the total with fine grained and homogeneously distributed A and F phases(Fig.1).After being welded by a specific welding thermal cycle to the material,i.e. Tmax=1350°C and t8/5=20s,microstructure may change from fine grained morphology to coarse grained morphology and from homogeneously distributed of A phase to a concentration of A phase(Fig.2).Meanwhile,the proportion of A phase reduced from 35% to 5-10°o.For this reason it is known as welded coarse grained zone(CGZ).In association with difference of microstructure between base metal and welded CGZ,so chloride SCC resistance also differ from each other.Test procedures:Constant load tensile test(CLTT) were performed for recording Esce-t curve by which corrosion cracking growth can be described, tf,fractured time,can also be recorded by the test which is taken as a electrochemical behavior and mechanical property for SCC resistance evaluation. Test environment:143°C boiling 42%MgCl2 solution is used.Besides, micro analysis were conducted with light microscopy(LM),SEM,TEM,and Auger energy spectrum(AES) so as to reveal the correlation between the data generated by the CLTT results and micro analysis.

Manipulate Me

2020 ◽  
Vol 36 (4) ◽  
pp. 554-562
Author(s):  
Alica Thissen ◽  
Frank M. Spinath ◽  
Nicolas Becker
Keyword(s):  
High School Students ◽  
Spatial Ability ◽  
Convergent Validity ◽  
Item Difficulty ◽  
Test Results ◽  
Response Elimination ◽  
School Students ◽  
Test Environment ◽  
Response Options ◽  
Construction Task

Abstract. The cube construction task represents a novel format in the assessment of spatial ability through mental cube rotation tasks. Instead of selecting the correct answer from several response options, respondents construct their own response in a computerized test environment, leading to a higher demand for spatial ability. In the present study with a sample of 146 German high-school students, we tested an approach to manipulate the item difficulties in order to create items with a greater difficulty range. Furthermore, we compared the cube task in a distractor-free and a distractor-based version while the item stems were held identical. The average item difficulty of the distractor-free format was significantly higher than in the distractor-based format ( M = 0.27 vs. M = 0.46) and the distractor-free format showed a broader range of item difficulties (.02 ≤  pi ≤ .95 vs. .37 ≤  pi ≤ .63). The analyses of the test results also showed that the distractor-free format had a significantly higher correlation with a broad intelligence test ( r = .57 vs. r = .17). Reasons for the higher convergent validity of the distractor-free format (prevention of response elimination strategies and the broader range of item difficulties) and further research possibilities are discussed.

Influence of a beacon on spatial learning based on the shape of the test environment.

2001 ◽  
Vol 27 (4) ◽  
pp. 329-344 ◽  
Author(s):  
John M. Pearce ◽  
Jasper Ward-Robinson ◽  
Mark Good ◽  
Clayton Fussell ◽  
Aydan Aydin
Keyword(s):  
Spatial Learning ◽  
Test Environment

Herbicide Tolerance Of Transgenic `Stevens' Cranberry Plants Depends on the Test Environment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 517a-517
Author(s):  
Eric L. Zeldin ◽  
Rodney A. Serres ◽  
Brent H. McCown
Keyword(s):  
Growth Form ◽  
Herbicide Tolerance ◽  
Genetically Engineered ◽  
Shoot Tip ◽  
Test Environment ◽  
Growth Environment ◽  
Commercial Formulation ◽  
Tolerance Level ◽  
Delayed Growth ◽  
Significant Injury

`Stevens' cranberry was genetically engineered to confer tolerance to the broad spectrum herbicide glufosinate. Initially, herbicide tolerance was verified by spraying greenhouse plants with the commercial formulation Liberty. Although one transformant showed significant tolerance, the tolerance level was below that required to kill goldenrod, a common weed of cranberry beds. This transformant was propagated and the plants established outdoors in a coldframe, yielding a growth form more typical of field-grown plants than that of greenhouse-grown plants. These plants, as well as untransformed cranberry and goldenrod plants, were sprayed with various levels of the herbicide. The transformed plants were not killed at glufosinate concentrations up to 1000 ppm, although delayed growth did occur. Some runner tip injury was observed at 500 ppm as well as widespread shoot tip death at higher levels. The above-ground parts of goldenrod plants were killed at 400 ppm with significant injury at 200 ppm. Untransformed cranberry plants were killed at 300 ppm and had extensive tip death even at 100 ppm. Transformed cranberry plants with confirmed “field” tolerance were re-established in the greenhouse and new vegetative growth was forced. When these plants were sprayed with glufosinate, significant shoot tip injury was observed at levels as low as 100 ppm. The degree of herbicide tolerance of transformed cranberry appears to be modulated by the growth environment, which may affect the expression of the inserted genes or the physiological sensitivity of the impacted tissues.

scholarly journals Additive Manufacturing Under Lunar Gravity and Microgravity

2021 ◽  
Vol 33 (2) ◽  
Author(s):  
B. Reitz ◽  
C. Lotz ◽  
N. Gerdes ◽  
S. Linke ◽  
E. Olsen ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Spare Parts ◽  
Manufacturing Processes ◽  
Complex Structures ◽  
Lunar Gravity ◽  
Limited Extent ◽  
Test Environment ◽  
Manufacturing Tests ◽  
Laser Experiments ◽  
Materials Used

AbstractMankind is setting to colonize space, for which the manufacturing of habitats, tools, spare parts and other infrastructure is required. Commercial manufacturing processes are already well engineered under standard conditions on Earth, which means under Earth’s gravity and atmosphere. Based on the literature review, additive manufacturing under lunar and other space gravitational conditions have only been researched to a very limited extent. Especially, additive manufacturing offers many advantages, as it can produce complex structures while saving resources. The materials used do not have to be taken along on the mission, they can even be mined and processed on-site. The Einstein-Elevator offers a unique test environment for experiments under different gravitational conditions. Laser experiments on selectively melting regolith simulant are successfully conducted under lunar gravity and microgravity. The created samples are characterized in terms of their geometry, mass and porosity. These experiments are the first additive manufacturing tests under lunar gravity worldwide.

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