scholarly journals A systematic examination of the relationships between CDOM and DOC in inland waters in China

2017 ◽  
Vol 21 (10) ◽  
pp. 5127-5141 ◽  
Author(s):  
Kaishan Song ◽  
Ying Zhao ◽  
Zhidan Wen ◽  
Chong Fang ◽  
Yingxin Shang

Abstract. Chromophoric dissolved organic matter (CDOM) plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC) has been investigated, and this significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. The current study examined samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China for tracking the variation of the relationships between DOC and CDOM. The regression model slopes for DOC vs. aCDOM (275) ranged from extremely low 0.33 (highly saline lakes) to 1.03 (urban waters) and 3.01 (river waters). The low values were observed in saline lake waters and waters from semi-arid or arid regions, where strong photobleaching is expected due to less cloud cover, longer water residence time, and daylight hours. In contrast, high values were found in waters developed in wetlands or forest in Northeast China, where more organic matter was transported from catchment to waters. The study also demonstrated that closer relationships between CDOM and DOC were revealed when aCDOM (275) were sorted by the ratio of aCDOM(250)∕aCDOM (365), which is a measure for the CDOM absorption with respect to its composition, and the determination of coefficient of the regression models ranged from 0.79 to 0.98 for different groups of waters. Our results indicate the relationships between CDOM and DOC are variable for different inland waters; thus, models for DOC estimation through linking with CDOM absorption need to be tailored according to water types.

2017 ◽  
Author(s):  
Kaishan Song ◽  
Ying Zhao ◽  
Zhidan Wen ◽  
Chong Fang ◽  
Yingxin Shang

Abstract. Chromophoric dissolved organic matter (CDOM) plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC) has been investigated, and the significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. An algorithm has been developed to retrieve DOC via CDOM absorption (aCDOM) at 275 and 295 nm for coastal waters, but it is still unclear for the relationship between DOC and aCDOM in other types of waters. The current study examined the samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China. The regression model slopes for DOC versus aCDOM(275) ranged from extreme low 0.33 (highly saline lakes) to 1.03 (urban waters) and 3.13 (river waters). The low values were observed in saline lake waters and waters from semi-arid or arid regions where strong photo-bleaching is expected due to thin ozone layers, less cloud cover, longer water residence time and daylight hours. In contrast, high values were found in waters developed in wetlands or forest in Northeast China, where massive organic matter was transported from catchment to waters. The study also demonstrated that stronger relationships between CDOM and DOC were revealed when aCDOM(275) were sorted by the ratio of aCDOM(250) to aCDOM(365), which is a tracer for the CDOM absorption with respect to its composition, and the determination of coefficient of the regression models ranged from 0.78 to 0.99 for different groups of waters. Our results indicated the relationships between CDOM and DOC are variable for different inland waters, and therefore remote sensing models for DOC estimation through linking with CDOM absorption need to be tailored according to water types.


Author(s):  
M. P. Smirnov

The article examines general regularities of the formation of dissolved organic matter (DOM), salinity (∑), the acid-alkaline indicators (pH) river waters in the mountains with various types of altitudinal zonation in Russia and CIS countries. The analysis is based on the results of many years of experimental studies in the network of the Roshydromet. The reaction of water of rivers in a southerly direction in accordance with changes in landscape-geochemical conditions are sequentially changed from acidic in the tundra of the Arctic to neutral in the tundra and taiga, slightly alkaline in forest-meadow and alkaline in a desert and subtropical mountains. The average annual salinity water of the mountain rivers in two Northern types of vertical zones is 42 and 74 mg/l, in two Southern types – 140 and 450 mg/l. The average annual values of permanganate (PO) and bichromate (BO) oxidation, and color of river water in xerophytic desert-subtropical mountains are small (3 and 7), and increase to medium and slightly increased grades into humid tundra and taiga, tundra of the Arctic, and the forest meadow mountains (7–8 and 13–18 mg O/l). Relationships PO:BO change from 62% in the tundra of the Arctic up to 50%, 41% and 35% in the tundra and taiga, forest-meadow and desert-subtropical mountains. The content of humic (HA) and fulvic (FA) acids is also maximum in two Northern types of vertical zones (0.224 and 1.80 mg/l) and decreases in the two Southern types to 0.013 and 0.067, 0.373 and 0.637 mg/l. The relationship of contents of HA and FA decreases to the South in forest-grassland and desert-subtropical mountains in 1.3 and 3.7 times.


1966 ◽  
Vol 17 (2) ◽  
pp. 169 ◽  
Author(s):  
WD Williams

The relationship between specific conductance and concentration of total dissolved solids was investigated in 62 samples from Australian lakes over a wide range of concentration of total dissolved solids (from 0.5 to >200‰). A high correlation was found particularly in highly saline lakes. This suggests that with much greater confidence than elsewhere conductivity determinations may be used in Australia as an indication of the amounts of total dissolved solids in lake waters over a wide range of concentration.


2016 ◽  
Author(s):  
Kaishan Song ◽  
Ying Zhao ◽  
Zhidan Wen ◽  
Jianhang Ma ◽  
Tiantian Shao ◽  
...  

Abstract. Chromophoric dissolved organic matter (CDOM) plays a vital role in aquatic ecosystems. Strong relationship has been proven between CDOM and dissolved organic carbon (DOC), which set the basis for remote estimation of DOC with remote sensing data. An algorithm has been developed to retrieve DOC via CDOM absorption at 275 and 295 nm with coastal waters. However, the relationship between DOC and aCDOM(275) and aCDOM(295) for different types of inland waters are still not clear. Further, is the relationship stable with different types of inland waters? In the current investigation, samples from fresh lakes, saline lakes, rivers or streams, urban water bodies, ice-covered lakes were examined. The regression model slopes range from 1.03 for urban waters to 3.13 for river water, with extreme low slope value for highly saline waters (slope is about 0.3); while coefficient of determinations (R2) range from 0.71 (urban waters) to 0.93 (winter waters). The specific CDOM absorption (SUVA254) showed the similar trend, i.e., low values were observed for saline water and waters from semi-arid or arid regions, where strong photo-bleaching is expect due to thin ozone layers, less cloud cover, longer water residence time and sunshine hours. In the contrast, high values were measured with waters developed in wetlands or forest in Northeast China, where inverse environmental settings were witnessed. The investigation also demonstrated that stronger relationships between CDOM and DOC were revealed when CDOM275 were sorted by SUVA254 (0.78 < R2 < 0.98) or the ratio of CDOM250:CDOM365 (0.78 < R2 < 0.99). Our results highlight that non-unified relationship exhibits for different types of inland waters, and remote sensing models for DOC need to be tuned with different inherent optical parameters obtained from various types of waters for quantification of DOC in inland waters.


2021 ◽  
Vol 32 ◽  
pp. 02008
Author(s):  
Nina Masyutenko ◽  
Alexey Kuznetsov ◽  
Maxim Masyutenko ◽  
Tatiana Pankova

The article is devoted to the study of the relationship and the determination of the dependence of winter wheat yield on the content and composition of the organic matter of typical chernozem, the determination of its optimal parameters in different by hydrothermal conditions years. The research was carried out in 2018-2019 in a typical heavy-loamy chernozem in the experimental field of the Kursk FARC. Coupled studies of the yield of winter wheat Synthetics and indicators of soil organic matter in the topsoil were carried out on 30-meter sites during the harvest period. The range of fluctuations in the content and composition of organic matter in the soil, the yield of winter wheat at the studied sites allowed us to apply information and logical analysis within the framework of the analyzed soil-plant system. A high dependence of winter wheat yield on the content and composition of soil organic matter was established, in 2018 the coefficients of information transfer efficiency varied from 0.23 to 0.17, in 2019 from 0.32 to 0.18. It was found that in dry 2019 the dependence of winter wheat yield on the biogenicity of mobile humus substances, the lability of humus, and microbial biomass has increased, and the influence of humus has decreased. It is established that in the studied years the significance of the parameters for the formation of winter wheat yield remained, the degree of their influence and sometimes the nature of the direction of the relationship changed. The optimal parameters of indicators of soil organic matter in the arable layer of chernozem typical for obtaining the yield of winter wheat Synthetic 5.45-7.24 t/ha in a favorable by hydrothermal conditions year and 4.78-7.19 t/ha in a dry year were established.


1973 ◽  
Vol 81 (3) ◽  
pp. 533-536 ◽  
Author(s):  
K. W. Moir

SUMMARYIn oven-dried whole plants from three regrowths of four varieties of Panicum maximum, leaf and stem of normal and stunted oats at three stages of first growth, leaf and stem of rape and the whole plant of millet, cell wall ranged from 14 to 77% of the organic matter. In vitro digestible cell wall ranged from 13 to 46% of the organic matter and was closely related to the cell wall (residual standard deviation, ± 2·5). In 16 legume hays the average in vitro digestible cell wall was 22·1% of the forage organic matter compared with an average value of 20·5% found previously from in vivo digestibility experiments with legumes. An unsatisfactory feature of the in vitro digestibility determination was that in silages and low quality grass hays, the digestible cell wall was low relative to known in vivo values for these forage types. The separate determinations of cell wall and in vitro digestible cell wall would add to the confidence that can be placed on estimates of in vivo digestibility from laboratory measurements. Often, the determination of cell-wall content is sufficient for this purpose.


1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.


2016 ◽  
pp. 137-142
Author(s):  
V.O. Benyuk ◽  
◽  
V.M. Goncharenko ◽  
T.R. Nykoniuk ◽  
◽  
...  

The objective: to еxplore the relationship between the activity of endometrial proliferation and the state of the local immune response in the uterus in the conditions berprestasi process. Patients and methods. Examined 228 women of reproductive and perimenopausal age with endometrial pathology using ultrasound and then performing hysteroresectoscopy. Determination of the concentrations of the cytokines IL-1, IL-2, IL-6 and TNF was performed by solid phase ELISA. Results. Found a trend that confirms the loss of sensitivity to hormones at the stage of malignancy of the endometrium and can be used as diagnostic determinants in determining the nature of intrauterine pathology and criterion of the effectiveness of conservative therapy. Conclusion. Improving etiopatogenetice approach to the therapy of hyperplastic proce.sses of endometrium with determination of receptor phenotype of the endometrium is a research direction in modern gynecology, which will help to improve the results of treatment and prevention of intrauterine pathology. Key words: endometrial hyperplasia,the receptors for progesterone and estrogen, immunohistochemical method.


2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.


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