نتایج جستجو برای: limestone

تعداد نتایج: 5717  

Journal: :British journal of industrial medicine 1955
A T DOIG

Limestone dust is generally regarded as being relatively harmless. In this paper I wish to record eight cases of pneumoconiosis in limestone workers, in all of which limestone played the sole or principal aetiological part. My attention was first drawn to the condition in November, 1950, when I saw the chest radiograph of a patient whose occupation was limestone crushing. The appearances were m...

2017
Charles A. Cravotta Suzanne J. Ward Jane M. Hammarstrom

Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite m...

Journal: :Journal of animal science 1990
M L Christiansen K E Webb

Effects were evaluated of high dietary levels of magnesium oxide (MgO) or limestone on DM, OM and CP digestibility, N balance and intestinal absorption of amino acids by lambs fed a high concentrate diet. Twelve wether lambs equipped with abomasal and ileal cannulas were blocked by weight and breeding and allotted to treatments in a randomized block design in two consecutive trials. Diets were ...

2016
Thor-Seng Liew Liz Price Gopalasamy Reuben Clements

15 Biodiversity conservation is now about prioritisation, especially in a world with limited 16 resources and so many habitats and species in need of protection. However, we cannot 17 prioritise effectively if historical and current information on a particular habitat or species 18 remains scattered. Several good platforms have been created to help users to find, use and 19 create biodiversity ...

2011

Site geology: The geology of the Oak Park site is one of limestone-drift materials overlying regional limestone-bedrock (over which two broad groups of soils occur: light-textured gravelly soils derived from limestone, and more heavy-textured soils derived from till). The soil underlying Miscanthus-plantations used in the experiments the former type, with a perched clay/subsoil layer under the ...

2017
Ahmet AYDIN Emine AVŞAR AYDIN

X-ray mammography is widely used for detection of breast cancer. Besides its popularity, this method did not have the potential of discriminating a tumor covered with limestone from a pure limestone mass. This might cause misdetection of some tumors covered with limestone or unnecessary surgery for a pure limestone mass. In this study, Ultra-Wide Band (UWB) signals are used for the imaging. A f...

2001
J. Shan

Septic tanks are the second largest source of groundwater nitrate contamination in Nebraska. In this study, the feasibility of coupling a conventional lateral field with a sulfur/limestone layer to treat nitrate in septic tank effluent was investigated using column reactors to simulate the septic tank soil adsorption system. The effects of different hydraulic loading rates, nitrogen loading rat...

2018
Jung Hwan Hyun Bang Yeon Lee Yun Yong Kim

This paper presents the results of an experimental study on the effect of limestone powder on the compressive strength, tensile behavior, and micromechanical parameters of a highly ductile cement composite incorporating limestone powder. Four mixtures were determined according to the replacement ratio of cement with limestone powder. A series of experiments including compressive strength, uniax...

Journal: :Bioresource technology 2012
R Li Z P Zhong B S Jin A J Zheng

Fast pyrolysis of rice husk was performed in a spout-fluid bed to produce water-soluble organics. The effects of mineral bed materials (red brick, calcite, limestone, and dolomite) on yield and quality of organics were evaluated with the help of principal component analysis (PCA). Compared to quartz sand, red brick, limestone, and dolomite increased the yield of the water-soluble organics by 6-...

2017
Junn Kitt Foon Gopalasamy Reuben Clements Thor-Seng Liew

Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed...

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