The Effect of Rainfall on Carbon and Nitrogen Contents, and Carbon-Nitrogen Ratios of Hawaiian Soils

1938 ◽  
Vol 2 (C) ◽  
pp. 455-459 ◽  
Author(s):  
L. A. Dean
Keyword(s):  
Carbon And Nitrogen ◽  
Nitrogen Contents

Effects of elevated air CO2 concentrations on the carbon and nitrogen contents of rice and winter wheat

2021 ◽  
Author(s):  
Ximing Deng ◽  
Shutao Chen ◽  
Chunhua Lv ◽  
Kai Yang ◽  
Dongyao Shang ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Carbon And Nitrogen ◽  
Co2 Concentrations ◽  
Nitrogen Contents

Effects of Chemical Compositions of Welding Rods on J-R Fracture Resistances and Tensile Properties of Type 347 Welds

2007 ◽  
Vol 539-543 ◽  
pp. 4105-4110
Author(s):  
Ji Hyun Yoon ◽  
Bong Sang Lee ◽  
Eui Pak Yoon
Keyword(s):  
Tensile Properties ◽  
Arc Welding ◽  
Fracture Resistance ◽  
Chemical Compositions ◽  
High Fracture ◽  
Carbon And Nitrogen ◽  
Gas Tungsten Arc ◽  
Weld Metals ◽  
Δ Ferrite ◽  
Nitrogen Contents

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.

scholarly journals Analysis of the Performance of two Rangeland Protocols, Monitoring and Assessment

2016 ◽  
Vol 5 (2) ◽  
pp. 47
Author(s):  
Soumana Idrissa ◽  
Ása L. Aradóttir ◽  
Sigþrúður Jónsdóttir
Keyword(s):  
Ecological Status ◽  
Health Indicators ◽  
Ecological Condition ◽  
Lower Amount ◽  
Barren Area ◽  
Carbon And Nitrogen ◽  
Site Characteristics ◽  
The One ◽  
Monitoring Protocols ◽  
Nitrogen Contents

<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>

Interspecific plant competition increases soil labile organic carbon and nitrogen contents

2020 ◽  
Vol 462 ◽  
pp. 117991
Author(s):  
Miaoying Wang ◽  
Jing Yang ◽  
Hailun Gao ◽  
Wenshi Xu ◽  
Mingqiu Dong ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Plant Competition ◽  
Labile Organic Carbon ◽  
Carbon And Nitrogen ◽  
Soil Labile Organic Carbon ◽  
Nitrogen Contents

Influences of Carbon and Nitrogen Content on the Precipitation of 18Cr18Mn Steel

2014 ◽  
Vol 789 ◽  
pp. 297-302
Author(s):  
Jing Yuan Li ◽  
Fei Fang ◽  
Yi De Wang ◽  
Bo Li ◽  
Xiang Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Cast Steel ◽  
Austenitic Stainless Steels ◽  
Aging Treatment ◽  
Solidification Process ◽  
Σ Phase ◽  
Carbon And Nitrogen ◽  
Transmission Electron ◽  
Carbon And Nitrogen Content ◽  
Nitrogen Contents

The effect of carbon and nitrogen contents on microstructure and the mechanism of precipitation of 18Cr18Mn steels at as-cast and aging treatment state were investigated by thermodynamics calculation, optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results show that the increase in carbon and nitrogen contents promotes the precipitation of carbides and nitrides, respectively, inhibiting σ phase precipitation during solidification process. The rod-like σ phases present in 18Cr18Mn0.44N as-cast steel with 0.025%C. The coarse lamellar structure Cr23C6 phases with a space width of 0.34μm exist in 18Cr18Mn0.44N as-cast steel with 0.16%C. However, Cr23C6 and σ phase disappear in the interior of the grains and a small amount of nitrides exist only in grain boundaries of 18Cr18Mn0.72N0.020C as-cast steel. The precipitation of Cr23C6 and σ phases are greatly inhibited in high nitrogen austenitic stainless steels at 800°C aging treatment. Additionally, Cr2N, the main precipitation phase, nucleates at austenitic grain boundary and grows towards inner grains with a lamellar morphology. Moreover, the quantity of Cr2N increases and incubation time of it decreases as nitrogen or carbon content increasing.

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