scholarly journals Fluorine Speciation in Loess in The Shaanxi Loess Plateau, Related Quality Assessment And Exposure Risks Implication

Author(s):  
Lin Deng ◽  
Jiangxia Wang ◽  
Bin Xu ◽  
Xiaoting Yang ◽  
Anyan Hu

Abstract In this study, distributing characteristics of five fluorine (F) species in loess in the Shaanxi Loess Plateau (SLP) were determined including unextractable residual F (Fre), extractable water-soluble F (Fws), exchangeable F (Fex), F bound to Fe-Mn oxides (Ffm), and F bound to organics (For). The results show that unextractable Fre represents most percentage of Ftf in loess. Of the four extractable F species, the content of Fws is higher than the other three extractable F species in most loess samples. The loess in the southeast SLP has the highest Fws content while the loess in the southwest has the highest Ftf content. And the loess in the north SLP contains the lowest overall concentrations of Ftf and Fws. Similar to Fws, the respective content of Fex, Ffm, and For in the loess is also very low. However, the total of them and Fws cannot be negligible for F mobility in loess. Overall, the loess in the SLP can be assessed as inferior quality in terms of F as a result of high Fws content in most samples. Based on the F speciation in the loess, F exposure to grazing animals and humans, in fact to children, was assessed, indicating that F in the loess in the southwest SLP might pose a much greater risk to grazing animals than in other part of SLP as the loess contains more Ftf. However, there is no concern for the children’s exposure to loess F via ingestion in the study area in the present condition. As for the loess F risk to groundwater, it can be concluded that not only Fws but also the other extractable F including Fex, Ffm and For in loess may be responsible for the F enrichment in local groundwater in the area with the aid of the characteristics of F speciation in loess and distribution of local high-fluoride groundwater.

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.


2018 ◽  
Vol 69 (2) ◽  
pp. 305-309 ◽  
Author(s):  
Daniela Gitea ◽  
Simona Vicas ◽  
Manuel Alexandru Gitea ◽  
Sebastian Nemeth ◽  
Delia Mirela Tit ◽  
...  

Our study compares the content in polyphenolic compounds and hypericin, in four species of Hypericum - H. perforatum L., H. maculatum Cr., H. hirsutum L., H. tetrapterum Fr. (syn. Hypericumacutum Mnch.) harvested from spontaneous flora in the north-western area of Transylvania, Romania. These species represent an important source of such compounds with different biological actions. After making the extracts, they were subjected to HPLC-SM analysis. The presence of rutoside in the largest amount (462.82 mg %) in the H. perforatum extract was observed, this containing most of the flavonoid heterosides. For the species H. maculatum, the presence in a much higher amount of the hyperoside (976.36 mg %) is characteristic compared to the other species. Quercetol is the best represented of the flavonoid aglycons, its concentration being the highest in H. hirsutum (659.66 mg %). The hypericin content ranges from 0.2171 g % in the H. tetrapterum extract, to 0.0314 g % in the methanol extract of H. maculatum.The highest antioxidant properties measured by FRAP method were recorded in the case of H. perforatum and H. maculatum.


Author(s):  
Mehrdad Rafiepourgatabi ◽  
Alistair Woodward ◽  
Jennifer A. Salmond ◽  
Kim Natasha Dirks

Children walking to school are at a high risk of exposure to air pollution compared with other modes because of the time they spend in close proximity to traffic during their commute. The aim of this study is to investigate the effect of a walker’s route choice on their exposure to ultrafine particles (UFP) on the walk to school. During morning commutes over a period of three weeks, exposure to UFP was measured along three routes: two routes were alongside both sides of a busy arterial road with significantly higher levels of traffic on one side compared to the other, and the third route passed through quiet streets (the background route). The results indicate that the mean exposure for the pedestrian walking along the background route was half the exposure experienced on the other two routes. Walkers on the trafficked side were exposed to elevated concentrations (>100,000 pt/cc) 2.5 times longer than the low-trafficked side. However, the duration of the elevated exposure for the background route was close to zero. Public health officials and urban planners may use the results of this study to promote healthier walking routes to schools, especially those planned as part of organized commutes.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 307
Author(s):  
Makoto Inoue ◽  
Atsushi Ugajin ◽  
Osamu Kiguchi ◽  
Yousuke Yamashita ◽  
Masashi Komine ◽  
...  

In this study, we investigated the effects of the Tibetan High near the tropopause and the North Pacific High in the troposphere on occurrences of hot or cool summers in Japan. We first classified Japan into six regions and identified hot and cool summer years in these regions from a 38-year sample (1980–2017) based on the monthly air temperature. To investigate the features of circulation fields over Asia during hot and cool summers in Japan, we calculated the composite differences (hot summer years minus cool summer years) of several variables such as geopotential height, which indicated significant high-pressure anomalies in the troposphere and lower stratosphere. These results suggest that both the North Pacific and the Tibetan Highs tend to extend to Japan during hot summer years, while cool summers seem to be associated with the weakening of these highs. We found that extension of the Tibetan High to the Japanese mainland can lead to hot summers in Northern, Eastern, and Western Japan. On the other hand, hot summers in the Southwestern Islands may be due to extension of the Tibetan High to the south. Similarly, the latitudinal direction of extension of the North Pacific High is profoundly connected with the summer climate in respective regions.


1874 ◽  
Vol 1 (1) ◽  
pp. 1-2
Author(s):  
Edward Hull

This granite forms an isolated mass, rising into two eminences a few miles south of Louisburg, called Corvock Brack (1287 feet) and Knockaskeheen (1288 feet). It is a greyish granite—generally fine—grained—consisting of quartz, two felspars,—one orthoclase, the other triclinic, probably oligoclase—and dark green mica. In some places there are patches in which the felspar assumes the appearance of “graphic granite.” Numerous boulders of this granite are strewn over the district to the north-west, and on the south side of Knockaskeheen; the rock is traversed by regular joints ranging N. 10 W., along which it splits off into nearly vertical walls. The position of the granite is shown on Griffith's Geological Map of Ireland, and it is surrounded by schistose beds, generally metamorphosed, and probably of Lower Silurian age. The granite itself is of older date than the Upper Llandovery beds, which lie to the southward.


2013 ◽  
Vol 20 (1) ◽  
pp. 99-122 ◽  
Author(s):  
Jonathan Fennell

High rates of desertion and surrender during the battles in North Africa in the summer of 1942 were a major factor in Eighth Army’s poor combat performance. At the time, some suggested that these problems were symptomatic of a lack of courage or even of cowardice. There are two broad strands to the conceptualization of courage and cowardice. One focuses on the willingness of the person to fight; the other puts emphasis on how actions express an individual’s ability to cope with fear. Whichever conceptualization is used, high morale motivates the soldier to fight and shields the ordinary recruit from his fear, preventing it from overcoming him in battle. Where morale fails, the soldier is left demotivated and burdened with his terror and, therefore, and is therefore prone to desertion or surrender. Because it is extremely difficult to maintain morale at a continuously high level in an environment governed by chance and managed by humans, all soldiers can find themselves in situations where their actions may be judged as cowardly. Alternatively, if they are properly motivated to fight and prepared by the state and military to deal with the unavoidable fear of combat, all soldiers can be labelled courageous. Accordingly, emotive terms should be avoided when attempting to describe rationally explainable outcomes. The undoubtedly negative connotations attached to cowardice in battle and the positive ones attached to courage are, therefore, arguably unhelpful in understanding Eighth Army’s performance in the summer of 1942 and the human dimension in warfare more generally.


2014 ◽  
Vol 641-642 ◽  
pp. 1141-1145 ◽  
Author(s):  
Hong Li Huang ◽  
Lin Luo ◽  
Jia Chao Zhang ◽  
Pu Feng Qin ◽  
Man Yu ◽  
...  

Pot experiments were performed to investigate the effect of compost amendment on the mobility of zinc through analysis of Zn fractions in heavy metal contaminated soil. The results showed that the total Zn concentration decreased 8.11%, 10.15%, 16.15%, 20.05%, 7.28% and 5.02% after the amendment of 0, 20, 40, 60, 80, 100 g/kg compost to soil and Brassica juncea harvest, respectively. Zn was mostly concentrated in the residual fraction and Fe-Mn oxides fraction in soil. The percentage of Zn in water-soluble fraction, organic fraction and residual fraction had no correlation with the amount of compost amendment. The percentage of Zn in the exchangeable fraction decreased and the percentage of Zn in Fe-Mn oxides fractions increased obviously. Furthermore, the mobility factor of Zn decreased significantly from 19.20% without compost amendment to 19.09%, 18.70%, 18.15%, 16.45% and 16.12% after the amendment of 0, 20, 40, 60, 80, 100 g/kg compost to soil, the compost amendment could lowered the mobility and phytotoxicity of zinc through bound to Fe-Mn oxides.


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