scholarly journals Geological Composition and Structure of the Filling Zone and Its Water-Resisting Property Evaluation on the Top of Ordovician Limestone

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Qiqing Wang ◽  
Wenping Li ◽  
Qiangqiang Liu
Keyword(s):  
North China ◽  
Clay Material ◽  
Water Control ◽  
Ordovician Limestone ◽  
Mining Depth ◽  
Property Evaluation ◽  
Field Investigations ◽  
Composition And Structure ◽  
Study Results ◽  
Lithological Composition

With the gradual increase in mining depth of coal fields in North China, the threat posed by karstic Ordovician limestone water to the safe stoping of mines is becoming increasingly prominent. Investigating the water-resisting property of the filling zone on the top of the Ordovician limestone provides the key to safe mining under pressure. This paper analyzed the formation process of the filling zone on the top of Ordovician limestone in North China, and by combining analysis results of several geological field investigations on Ordovician outcrops, the filling zone on the top of Ordovician limestone was divided into three water-resisting structures: (1) completely filled, (2) incompletely filled, and (3) nonfilled. Based on the lithological composition, logging curves, and the water inflow status of several field boreholes, various characteristics of these clay-filled zones were used to determine the mudstone content from top to bottom. Using the interbedded mudstone thickness ratio, relative argillaceous content, impermeable filling zone thickness, rock quality designation (RQD), and faulting as evaluation factors, this paper evaluated the water-resisting property of the filling zone in the study area based on feature-weighted fuzzy C-means clustering (WFCM) algorithm and determined the extent of each zone. The completely filled zone accounts for 46.9% of the total area, incompletely filled zone accounts for 23.9%, and the zone not filled with clay material accounts for 29.2%. As indicated by field investigations on the boreholes, the actual percent of each zone is similar to the theoretical results. The study results present a vital guide for Ordovician limestone water control in deep mining.

Hydrogeochemical evolution of Ordovician limestone groundwater in Yanzhou, North China

2012 ◽  
Vol 27 (16) ◽  
pp. 2247-2257 ◽  
Author(s):  
Yong Han ◽  
Guangcai Wang ◽  
Charles A Cravotta ◽  
Weiyue Hu ◽  
Yueyue Bian ◽  
...  
Keyword(s):  
North China ◽  
Ordovician Limestone ◽  
Hydrogeochemical Evolution

Mechanical Properties and Stress-Strain Behaviour of Binary and Ternary Composites Based on Polyolefins and Vegetable Fillers

2017 ◽  
Vol 265 ◽  
pp. 221-226 ◽  
Author(s):  
E.E. Mastalygina ◽  
A.A. Popov
Keyword(s):  
Mechanical Properties ◽  
Filler Content ◽  
Low Density Polyethylene ◽  
Biological Degradation ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Composition And Structure ◽  
Study Results ◽  
Wide Range ◽  
Dimensional Parameters

Binary and ternary composites based on isotactic polypropylene and low-density polyethylene in a wide range of ratios without and with filler content have been investigated. Micron-scale vegetable cellulosic components initiating biological degradation have been used as fillers for polymeric composites. The analysis of stress-strain behaviour of the composites has shown a non-additive dependency of elongation and tensile strength at break on blends composition. Based on this study results the composition and structure of polymeric phase of binary and ternary composites, as well as dimensional parameters of filler particles have a significant impact on stress-strain behaviour of the materials. The main regularities determining materials mechanical properties have been discovered, that, in turn, could be used for predicting service behaviour of composites under investigation.

scholarly journals Frugivorous bats drink nutrient- and clay-enriched water in the Amazon rain forest: support for a dual function of mineral-lick visits

2013 ◽  
Vol 29 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Simon J. Ghanem ◽  
Hans Ruppert ◽  
Thomas H. Kunz ◽  
Christian C. Voigt
Keyword(s):  
Stream Water ◽  
Secondary Compounds ◽  
Video Observation ◽  
Dual Function ◽  
Clay Material ◽  
Water Control ◽  
Amazon Rain Forest ◽  
Faecal Samples ◽  
Central Amazonia ◽  
Mineral Licks

Abstract:In Central Amazonia, large mammals create water-filled puddles when consuming soil. These mineral licks are visited by pregnant and lactating frugivorous bats; possibly for two reasons. Frugivorous bats could supplement their mineral-depleted fruit diet by drinking salty water, or they could buffer dietary plant secondary compounds by consuming soil. We analysed bat fruits from Ecuador and showed that they are depleted in elemental concentrations (Na, K, P) compared with similar fruits collected from Costa Rica, where no mineral licks occur (n = 32). Analyses of water from Ecuador revealed that water samples from six mineral licks contained more physiologically relevant elements (Na, K, Mg, Ca) than four samples from river and stream water control sites (Mann–WhitneyU-test). In support of the nutrient supplement hypothesis, we observed bats drinking mineral-enriched water at these licks (video observation). Furthermore, blood collected from 68 bats differed in composition with respect to physiologically relevant minerals (Na, K, Mg, Fe) from that of frugivorous bats captured at control sites. To test whether frugivorous bats also consumed clay for detoxification, we checked for soil tracer elements in 31 faecal samples. Soil tracers are insoluble in water and, thus, are not included in a strict fruit diet. Bats from mineral licks showed higher aluminium soil tracer concentrations in their faeces than bat species that never visit licks, suggesting that frugivorous bats take up clay material at mineral licks. Our results provide evidence that frugivorous bats ingest soluble mineral nutrients and insoluble soil by consuming soil-enriched water at mineral licks, thus supporting the hypothesis that frugivorous bats of western Amazonia may derive a dual benefit from drinking water from mineral licks.

scholarly journals Modern sedimentation processes in glacial lakes on the Spitsbergen archipelago (on the example of Lake Bretjørna)

2021 ◽  
Vol 937 (4) ◽  
pp. 042096
Author(s):  
N I Meshcheriakov ◽  
G V Ilyin ◽  
E G Zhuvikina ◽  
G V Tarasov
Keyword(s):  
Organic Matter Content ◽  
Field Research ◽  
Matter Content ◽  
Geochemical Characteristics ◽  
Study Results ◽  
Lake Bottom ◽  
Component Content ◽  
Lake Bottom Sediments ◽  
Lithological Composition ◽  
Sedimentation Processes

Abstract The paper reviews the study results of sedimentation and formation of geochemical characteristics of glacial Lake Bretjørna sediment – as the example of postglacial process in inner areas of Arctic archipelagos. Field research and sampling were carried out in the winter of 2018. The properties of sediments along the profile of the lake were analyzed. The income and accumulation of heavy metals in sediment were assessed. The lithofacies characteristics of the sediments and their spatial distribution were determined. In the paper the main geochemical characteristics of the lake bottom sediments (granulometric composition, organic matter content, as well as the accumulation of Pb, Zn, Cu, Ni, Fe, Mn, Hg) are considered. The correlation between the lithological composition of sediments and their micro-component content are shown. Correlation between elements and terrigenous sediments income from Northern Scandinavia and the Kola Peninsula accumulated by the glacier and snow cover of the catchment is obtained. Three associations of trace elements in the group of studied elements are distinguished.

Using pillar-free mining technologies in gently dipping and self-ignitable coal seams

2020 ◽  
pp. 64-77
Author(s):  
D. D. Golubev
Keyword(s):  
Fire Hazard ◽  
Coal Pillar ◽  
Kuznetsk Coal ◽  
Coal Seams ◽  
State Behavior ◽  
Mining Depth ◽  
Study Results ◽  
Endogenous Fire ◽  
Determination Of Parameters ◽  
Coal Seam Thickness

Gently dipping coal seams of the Kuznetsk Coal Basin are cut exclusively by longwalls with preliminary drivage of twin gate ways. At the same time, the source of self-ignition in mines is pillars of coal left in mined-out areas. Endogenous fire hazard grows with higher losses of loose coal in mined-out areas due to a persistent increase in mining depth and in size of longwalls. This research aims at development of an alternative mining technology for gently dipping coal seams to reduce the risk of initiation of self-ignition sources in mined-out areas and at the determination of parameters of the technology elements as functions of coal seam thickness and mining depth. A new concept of preparatory works and actual mining in selfignitable coal seams is described. The study results obtained with numerical modeling of the stress-state behavior of rock mass and the developed technology elements at different stages of longwalling are presented. The studies show that endogenous fire hazard is reduced by means of extraction of coal pillar on the same line with face and due to elimination of aerological connection between the operating longwall and earlier mined-out area owing to construction of a separation belt made of solidifying materials between them. The cross-effect of the widths of the solidifying material belt and coal pillar as the elements of the developed technology is estimated.

scholarly journals Warming and Dimming: Interactive Impacts on Potential Summer Maize Yield in North China Plain

2019 ◽  
Vol 11 (9) ◽  
pp. 2588 ◽  
Author(s):  
Qi Hu ◽  
Xueqing Ma ◽  
Huayun He ◽  
Feifei Pan ◽  
Qijin He ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Climate Warming ◽  
North China Plain ◽  
North China ◽  
Growing Season ◽  
Maize Yield ◽  
Maturity Stage ◽  
Summer Maize ◽  
The Past ◽  
Study Results

Global warming and dimming/brightening have significant implications for crop systems and exhibit regional variations. It is important to clarify the changes in regional thermal and solar radiation resources and estimate the impacts on potential crop production spatially and temporally. Based on daily observation data during 1961–2015 in the North China Plain (NCP), the impacts of climate change associated with climate warming and global dimming/brightening on potential light–temperature productivity (PTP) of summer maize were assessed in this study. Results show that the NCP experienced a continuous warming and dimming trend in maize growing season during the past 55 years, and both ATT10 and solar radiation had an abrupt change in the mid-1990s. The period of 2000–2015 was warmer and dimmer than any other previous decade. Assuming the maize growing season remains unchanged, climate warming would increase PTP of summer maize by 4.6% over the period of 1961–2015, which mainly occurred in the start grain filling–maturity stage. On the other hand, as negative contribution value of solar radiation to the PTP was found in each stage, dimming would offset the increase of PTP due to warming climate, and lead to a 15.6% reduction in PTP in the past 55 years. This study reveals that the changes in thermal and solar radiation have reduced the PTP of summer maize in the NCP. However, the actual maize yield could benefit more from climate warming because solar radiation is not a limiting factor for the current low production level.

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