An experiment was conducted to evaluate the influence of different Ca sources (limestone, Ca chloride, and Lipocal, a fat-encapsulated tricalcium phosphate, TCP) in conjunction with 4 dietary levels of non-phytate P (NPP) on performance, ileal digestibility of Ca and P, and bone mineralization in broiler chickens. Calcium sources were also evaluated in vitro to measure acid-binding capacity (AB...

This study aimed at evaluating the effect of dietary calcium levels and the replacement of calcium sources with different particle size compositions on the performance and egg quality of brown layers in their second egg production cycle. A randomized block experimental design was applied with 12 treatments in a 3x4 factorial arrangement: three calcium levels (2.6, 3.2, 3.8 %) and four combinati...

Laboratory scale studies have repeatedly reported high P-retention in slag, a by-product of the steel manufacturing industry. Thus, it has emerged as a potential material to increase P-removal from constructed wetlands (CWs). However, several limitations were highlighted by field experiments, including the high pH of treated water and clogging. We hypothesized that the addition of sedimentary r...

Lime production is a process that entail complex material and energy transport and chemical reaction. Efficient lime production processes are realized via well structured design models approach . Simulation of such process design models essentially provides Information on the attractive features and technical limitations of such processes which serves as guide for normal operations. The choice ...

The attachment of the psammophytic alga Caulerpa mexicana Sond. ex Kütz., a coenocytic green alga, to crushed CaCO3 particles was examined utilizing the scanning electron microscope and fluorescently tagged antivitronectin antibodies. Plants attached to the substrate through morphologically variable tubular rhizoidal extensions that grew from the stolon. In this study, we describe two means of ...

Yes and no. These synthetic stones are in fact re-agglomerated materials. The process is explained in more detail later in the book. Basically, the principle is as follows: starting with a mineral substance such as eroded, disintegrated or naturally disaggregated rock – such as the limestone found everywhere in northern France – we give it a compact structure using a binder, a geological glue t...

BACKGROUND In a community in northern Chile, explosive procedures are used by two local industrial mines (gold, copper). We hypothesized that the prevalence of asthma and rhinoconjunctivitis in the community may be associated with air pollution emissions generated by the mines. METHODS A cross-sectional study of 288 children (aged 6-15 years) was conducted in a community in northern Chile usi...

ational statistics on coal-mining productivity show that—except during the 1970s—coal mines have become steadily more efficient. More coal is removed per hour of work, causing a drop in both mining costs and coal prices. However, a new Energy Laboratory study suggests that those national statistics do not tell the whole story. When the researchers analyzed productivity data for more than ninete...

Navigation canals are used for transport purposes. In order to allow safe navigation the water level should be kept in a certain range around the Normal Navigation Level (NNL). The water level is disturbed by known and unknown inputs, like tributaries, municipal water flows, rain, etc. Some of these inputs can be used to control the water level. If the geometry requires it, canal reaches are co...

In the early 1980’s, the world steel market collapsed. Since the almost exclusive use of ironore is in steel production, many iron-ore mines had to be shut down. We divide the major iron-ore producing countries into groups based on the threat of closure faced by iron-ore mines in the respective country. In countries where mines faced no threat of closure, the iron-ore industry had little or no ...