نتایج جستجو برای: limestone quarries
تعداد نتایج: 6283 فیلتر نتایج به سال:
Fifty Merino weaner sheep grazing on a wheat stubble at Wongan Hills were fed ad lib. either oat grain mixed with limestone (2% w/w) or just oat grain during the summer and autumn of 1985. The addition of limestone to the oat supplement increased the growth of the sheep from 39 g/day to 83 g/day (P<O.OOl) during the first 70 days of feeding. A summer thunderstorm resulted in a brief germination...
The Christmas copper mine is in the Banner mining district, Gila County, Arizona. It is 8 miles north of Winkelman and 22 miles south of Globe. The mine was opened in 1905; to the end of 1943 it had produced about 55,340,000 pounds of copper. In 1946 it was operated under lease. The ore is high-lime fluxing ore, required by the smelter at Hayden. The ore produced during 1942 averaged 2.16 perce...
Since ages, architects and artists worldwide have focused on usage of durable stones as marble and limestone for construction of beautiful and magnificent historic monuments as European Cathedrals, Roman, and Greek temples, Taj Mahal etc. But survival of these irreplaceable cultural and historical assets is in question these days due to their degradation and deterioration caused by number of bi...
Analyses of samples of the raw materials locally available for use in the Eaton (Hopewell) Furnace indicate that the iron ore and bituminous coal were of good smelting quality while the limestone (flux) was not. The limestone had a much higher then desirable silica content and a low calcium content. The limestone was insufficient to the task of removing impurities introduced through the fuel co...
Wt% of aragonite, a CaCO(3) polymorph, increased with higher hydraulic activity ( degrees C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)(2)-NaOH-Na(2)CO(3)). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 degrees C, whereas aragonite also started to crystallize over 10 degrees C. The crystallization of PCC is ...
iran has high potential and unique stone reserves in terms of variety of color, texture, quality, and economic value; nevertheless, in spite of growing mine production during the past decade, in many instances this potential has been overlooked. therefore it is necessary to investigate strategic factors of these mines. the purpose of this study is to evaluate and determine the best strategies f...
Introduction: Particulate matter (PM) is known as the most common cause of air pollution in the world. Activities of sand quarries are known as one of the emission sources in Tehran. This study aimed at investigating the geological and environmental factors of airborne particles in an active quarry in the west of Tehran. Material and Methods: Three methods of dust sampling were used. totally, ...
Alkali activated material has recently attracted great attention as an environmentally friendly building material. Generally, it exhibits higher mechanical properties and better durability when compared with Portland cement based materials. In this article, mixed alkali activated systems consisting of N-A-S-H and C-A-S-H hydrated gels were produced, using metakaolin as a dominated starting mate...
Studies on actinobacterial diversity in limestone habitats are scarce. This paper reports profiling of actinobacteria isolated from Hundung limestone samples in Manipur, India using ARDRA as the molecular tool for preliminary classification. A total of 137 actinobacteria were clustered into 31 phylotypic groups based on the ARDRA pattern generated and representative of each group was subjected ...
The effects of a bio-treatment on limestone (here tuffeau) is measured over a large number of dryingimbibition cycles. A model based on a space-dependent permeability coefficient is proposed. It leads to a non-linear diffusion model which accounts for the deviation from the standard Washburn model. Keyword: Limestone, bio-mineralization, water transfer, imbibition, non-linear diffusion
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