Impact of anthropogenic and natural processes on the chemical compositions of precipitation at a rapidly urbanized city in Northwest China

2017 ◽  
Vol 76 (10) ◽  
Author(s):  
Jianguo Li ◽  
Zongxing Li ◽  
Qi Feng
Keyword(s):  
Northwest China ◽  
Chemical Compositions ◽  
Natural Processes

Influences of natural and anthropogenic processes on the groundwater quality in the Dagujia River Basin in Yantai, China

2019 ◽  
Vol 69 (2) ◽  
pp. 184-196 ◽  
Author(s):  
Henghua Zhu ◽  
Jianwei Zhou ◽  
Tingting Song ◽  
Haibo Feng ◽  
Zhizheng Liu ◽  
...  
Keyword(s):  
Groundwater Quality ◽  
Seawater Intrusion ◽  
Human Activities ◽  
Industrial Development ◽  
Anthropogenic Activities ◽  
Total Hardness ◽  
Chemical Components ◽  
Chemical Compositions ◽  
Rock Interaction ◽  
Natural Processes

Abstract Groundwater plays an important role in water supply and economic development for Yantai city, China. However, the groundwater quality has degraded due to the increase and expansion of agricultural and industrial development. It is urgent to acquire groundwater characteristics and distinguish impacts of natural factors and anthropogenic activities on the groundwater quality. Forty-six groundwater samples collected from different wells showed a great variation of chemical components across the study area. Most wells with higher total dissolved solids, total hardness, K+, Na+, Ca2+, Mg2+, Cl− and SO42− concentrations were located relatively close to the coastal zone. The factor analysis (FA) and hierarchical cluster analysis results displayed that seawater intrusion was the primary mechanism controlling the groundwater quality in the coastal areas. A three-factor model was proposed based on the FA and explained over 85% of the total groundwater quality variation: Factor 1, the seawater intrusion; Factor 2, the water–rock interaction and Factor 3 (NO3−), the human activities. Furthermore, the geographical maps of the factor scores clearly described the spatial distributions of wells affected by natural processes or human activities. The study indicated that both natural processes and human activities are the major factors affecting the chemical compositions of groundwater.

Biblical Tel Burna: contribution of POSL and PXRF to the discussion on sedimentary and site formation processes in archaeological contexts of the southern Levant

2021 ◽  
Author(s):  
Martin Janovský ◽  
Jan Horák ◽  
Oren Ackermann ◽  
Aharon Tavger ◽  
Deborah Cassuto ◽  
...  
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Human Activities ◽  
Site Formation ◽  
Chemical Compositions ◽  
Site Formation Processes ◽  
Archaeological Research ◽  
Southern Levant ◽  
Sedimentary Processes ◽  
Natural Processes

<p>An ancient tell is a multi-period archaeological site, where anthropogenic, and natural sedimentation processes took place. Although a tell is primarily an anthropogenic type of geomorphological feature, it is affected by natural processes as well. This contribution discusses how these processes can be determined within the context of archaeological research and how it is possible to differentiate and interpret past-human activities and natural processes. Tel Burna, a site intensively occupied from the Early Bronze to Iron Ages (3rd millennium BCE – 6th century BCE) located in the southern Levant, was chosen for this study of the studying sedimentary processes and chemical compositions of sediments. The sedimentary processes were studied in the course of an archaeological excavation using POSL (portable optically stimulated luminescence), granulometry and PXRF (portable X-ray fluorescence). Focusing on the area along the fortification walls, data was collected from strata around the casemate fortifications dating from the Late Bronze Age to the Late Iron Age.</p><p>The gradual increase of OSL values obtained inside the casemate wall, indicate accumulation of sediment during a long period of time. Whereas similar values along the entire profile outside the casemate wall indicate sediment accumulation in one-time event. This might be related to defensive preparations, allegedly in response to advances made by Sennacherib’s army in 701 BCE. Results from the PXRF demonstrated a correlation between the Cu, P, K, Zn, Mn content and human activities. Ca content decreased as sampling descended from the tell's surface, suggesting its origin in post-abandonment aeolian processes.  The results demonstrate that the use of POSL and PXRF can be useful for determining sedimentary processes at ancient tells. The presented abstract is adapted from the article published in Quaternary International in 2020.</p><p>Acknowledgements:</p><p>The research is supported by project “Geochemical insight into non-destructive archaeological research” (LTC19016) of subprogram INTER‐COST (LTC19) of program INTEREXCELLENCE by Ministry of Education, Youth and Sport of the Czech Republic.</p>

Analytical Electron Microscopy of Ion-Implanted Metals

1985 ◽  
Vol 43 ◽  
pp. 282-285
Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing
Keyword(s):  
Electron Microscopy ◽  
Ion Implantation ◽  
Friction And Wear ◽  
Analytical Electron Microscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Near Surface ◽  
The Past ◽  
Analytical Electron ◽  
Property Changes

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

1996 ◽  
Vol 54 ◽  
pp. 694-695
Author(s):  
Gejing Li ◽  
D. R. Peacor ◽  
D. S. Coombs ◽  
Y. Kawachi
Keyword(s):  
Electron Microscopy ◽  
Volcanic Rocks ◽  
Analytical Electron Microscopy ◽  
Metamorphic Rocks ◽  
New Mineral ◽  
Chemical Compositions ◽  
Low Grade ◽  
Fine Grained ◽  
Depth Analysis ◽  
Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

Chemical compositions from Biscogniauxia sp. PK15-040 fungus

2019 ◽  
Author(s):  
A Churat ◽  
W Mongkolthanaruk ◽  
N Suwannasai ◽  
N Wangsawat ◽  
S McCloskey
Keyword(s):  
Chemical Compositions

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

DANGEROUS GEOLOGICAL (NATURAL) PROCESSES IN THE AREA OF DERBENT (cause and investigation)

2019 ◽  
Vol 63 (4) ◽  
pp. 90-99
Author(s):  
Idrisov I.A. ◽  
◽  
Suleymanov V.K. ◽  
Cherkashin V.I. ◽  
◽  
...  
Keyword(s):  
Natural Processes
Sign in / Sign up

Export Citation Format

Share Document