We propose a definition for geometric mean of k positive (semi) definite matrices. We show that our definition is the only one in the literature that has the properties that one would expect from a geometric mean, and that our geometric mean generalizes many inequalities satisfied by the geometric mean of two positive semidefinite matrices. We prove some new properties of the geometric mean of ...

Ambient air particles in the ultrafine size range (diameter < 100 nm) may contribute to the health effects of particulate matter. However, there are few data on ultrafine particle deposition during spontaneous breathing, and none in people with asthma. Sixteen subjects with mild to moderate asthma were exposed for 2 hr, by mouthpiece, to ultrafine carbon particles with a count median diameter (...

A study was completed of more than 170,000 records of pediatric venous blood levels and supporting demographic information collected in New York City during 1970-1976. The geometric mean (GM) blood lead level shows a consistent cyclical variation superimposed on an overall decreasing trend with time for all ages and ethnic groups studied. The GM blood lead levels for blacks are significantly gr...

The data presented here supports the informational background of enzyme-based lignocellulose hydrolyzation, cellulase characterization, and sugar yield prediction for the work "Enzyme-based lignocellulose hydrolyzation - Sauter mean diameter of raw materials as a basis for cellulase performance characterization and yield prediction" by Glaser [1]. Glucose yields from the enzymatic hydrolysis of...

This paper, in considering aspects of the geometric mean sequence, offers new results connecting Jacobsthal and Horadam numbers which are established and then proved independently.

This report presents the geometric mean blood lead levels of an 80% cross-sectional sample of children aged 1-72 months in New Haven, Connecticut. Blood lead levels were related to age, sex and race. It was found that age and race were independently important sources of variation in blood lead levels. Sex of children in this age group was not related to differences in blood lead levels. The hig...

soil organic carbon has been the most important soil quality measurement factors and has intense relation with soil physical, chemical and biological characteristics. organic matter and its components are important factors of soil aggregates constitution and stability and play significant role in its structure.so, this research has been done for achieving this purpose. this area is arounding sa...

Silica nanoparticles (SNPs) are widely used all around the world and it is necessary to evaluate appropriate risk management measures. An initial step in this process is to assess worker exposures in their current situation. The objective of this study was to compare concentrations and morphologic characteristics of fumed (FS) and sol-gel silica nanoparticles (SS) in two manufacturing facilitie...

physical properties of four common iranian varieties of canola seeds (hyola, okapi, orient and slm) were evaluated as a function of their moisture contents. the average seed length and thousand seed mass varied linearly from 1.925 to 2.262 mm and from 3.06 to 4.84 g, respectively. the average diameter, geometric mean diameter, and sphericity varied non-linearly from 1.475 to 1.911 mm, 1.625 to ...

A study has been made of the compaction properties of two experimental starches, namely yam starch obtained from Dioscorea rotundata and rice starch obtained from Oryza sativa and the mechanical properties of their tablets, in comparison with those of official corn starch. The influences of the physical and geometric properties of the starch particles on the compression properties of the starch...