It is also important to notice how the modern periodic table is arranged. Although we have retained the format of rows and columns, which reflects a natural order, the rows of today's tables show elements in the order of Mendeleev's columns. In other words the elements of what we now call a "period" were listed vertically by Mendeleev. Chemical "groups" are now shown vertically in contrast to t...

Many visual tasks can be decomposed into a sequence of simpler subtasks. Ullman suggested that such subtasks are carried out by elemental operations that are implemented by specialized processes in the visual brain [Ullman, S. (1984). Visual routines. Cognition (18), 97-159]. According to this hypothesis, there are a limited number of elemental operations that, since they can be applied sequent...

Though exposure to air pollution has a detrimental effect on respiratory health, few studies have examined the association between elemental carbon exposure and lung function among schoolchildren. The aim of the present study was to present the association between short-term elemental carbon exposure and lung function in schoolchildren from Mexico City. 55 asthmatic and 40 non-asthmatic childre...

The rising importance of organohalogens in environmental, pharmaceutical, and biological applications has drawn attention to analysis of these compounds in recent years. Elemental mass spectrometry (MS) is particularly advantageous in this regard because of its ability to quantify without compound-specific standards. However, low sensitivity of conventional elemental MS for halogens has hampere...

How does consumer physiology and life history respond to them? And (3) What are their consequences for ecological processes in ecosystems? Elemental imbalances are defi ned by a mismatch between the elemental demands of a consumer and those provided by its resources. For example, carbon-tophosphorus (C:P) ratios in the suspended organic matter in lakes (i.e., algae, bacteria, and detritus) can ...

flocculation processes during estuarine mixing can reduce the elemental concentrations of river water. in the present investigation, natural flocculation processes concept is used to reduce the elemental contents of industrial wastewater. for this purpose, various amounts of saline water were added to an artificial industrial wastewater with known concentrations of heavy metals. the results of ...

occupational exposure to elemental mercury vapor usually occurs through inhalation during its utilizations. this leads to a variety of adverse health effects. in some islamic cities, this type of poisoning may occur during gilding of shrines using elemental mercury with gold. herein, we report on three male patients aged 20–53 years, who were diagnosed with occupational metallic mercury poisoni...

BACKGROUND Mercury and mercury compounds (inorganic and organic) can cause acute or chronic poisoning. Acute poisonings, especially with inorganic salts, are widely described, but only sparse data are available on intoxication from oral elemental mercury. We report a case of elemental mercury ingestion followed by pulmonary aspiration of the elemental mercury. CASE REPORT A 49-year-old woman ...

We have examined the effects of parasite infection on the mucosal architecture of mice maintained on an elemental diet (Vivonex). Techniques used were conventional histology, micro-dissection and measurement of individual villi and crypts, and measurement of crypt cell proliferation rate by a metaphase accumulation technique. In normal, non-parasitised mice the elemental diet caused no change i...

The surface energy is a fundamental property of the different facets of a crystal that is crucial to the understanding of various phenomena like surface segregation, roughening, catalytic activity, and the crystal's equilibrium shape. Such surface phenomena are especially important at the nanoscale, where the large surface area to volume ratios lead to properties that are significantly differen...