SULPHUR, CARBON, AND NITROGEN CONTENTS OF ORGANIC FRACTIONS FROM ACETYLACETONE EXTRACTS OF SOILS

1976 ◽  
Vol 27 (3) ◽  
pp. 324-330 ◽  
Author(s):  
N. M. SCOTT ◽  
G. ANDERSON
Author(s):  
Ximing Deng ◽  
Shutao Chen ◽  
Chunhua Lv ◽  
Kai Yang ◽  
Dongyao Shang ◽  
...  

2003 ◽  
Vol 67 (6) ◽  
pp. 1831-1841 ◽  
Author(s):  
Karina P. Fabrizzi ◽  
Alejandro Morón ◽  
Fernando O. García

2007 ◽  
Vol 539-543 ◽  
pp. 4105-4110
Author(s):  
Ji Hyun Yoon ◽  
Bong Sang Lee ◽  
Eui Pak Yoon

The objective of this investigation was to correlate the chemical composition of welding rods for gas tungsten arc welding with the fracture resistance and tensile properties of type 347 welds through the systematic tests and microstructural analyses. Five weld metals which differed in contents of carbon, nitrogen and niobium each other and a high δ-ferrite containing weld metal were deposited by the six different welding rods. J-R fracture resistance and tensile properties were evaluated for the type 347 welds. The microstructural examinations were performed to relate key microstructural features to mechanical properties. It was found that the contents of Nb(C,N) precipitates in type 347 welds were determined by the mixed function of carbon and nitrogen and niobium contents in welding rods. The strengths of type 347 welds were in direct proportion to the contents of Nb(C,N) and J-R fracture resistances were inversely proportional to the contents of Nb(C,N). It was concluded that the type 347 weld with high fracture resistance and adequate strength was obtainable by controlling the sum of carbon and nitrogen contents near 0.1wt% and a limitation of the carbon content below 0.04 wt% in welding rod.


2016 ◽  
Vol 5 (2) ◽  
pp. 47
Author(s):  
Soumana Idrissa ◽  
Ása L. Aradóttir ◽  
Sigþrúður Jónsdóttir

<p>This study compared and contrasted data from the stick and modified Braun-Blanquet monitoring protocols in three areas with different land use histories: an unrestored barren area, a young and old restored areas. The study areas are part of extensive degraded of birch woodland and willow shrubland that have partly been re-vegetated.Vegetation and site characteristics were assessed in the three areas using the two protocols and soil sampling to characterize the ecological status of a land that has been re-vegetated. The analysis of the two protocols data indicates similar tendency which is the improvement of the ecological condition of the restored areas compared to the unrestored area. The soil carbon and nitrogen contents increased when the pH decreased with the restoration age. The improvement is better at the old restored area which has received more fertilization compared to the young restoration. Stick method estimated greater cover of vascular plants, litters, mosses and rocks, and lower amount of bare ground than modified Braun-Blanquet. The two protocols provided similar estimates cover of lichens and sedges. Stick method also provided three supplementary indicators which were not included in modified Braun-Blanquet: plants base, basal and canopy gaps. Another observation that could be proved by further studies, stick seemed to be more precise and economical than modified Braun-Blanquet. The indicators provided by the two protocols were related to the three attributes of ecosystems and the rangelands health indicators. This study is a preliminary that cannot be able to recommend one method, but it advocates stick method to assess and monitor vegetation dominated by herbaceous layer as grassland and modified Braun-Blanquet for the one dominated by woody layer.</p>


2020 ◽  
Vol 462 ◽  
pp. 117991
Author(s):  
Miaoying Wang ◽  
Jing Yang ◽  
Hailun Gao ◽  
Wenshi Xu ◽  
Mingqiu Dong ◽  
...  

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