Co2+x+yMn1−xAl1−y intermetallic compounds have been prepared by arc melting and studied with X-ray diffraction and magnetization measurements to ascertain the effect of deviations of composition from the stoichiometry on the ferromagnetism of this system. Hysteresis loops registered at room temperature show a soft ferromagnetic behavior in excess Co. In off-stoichiometric alloys the saturation ...

Abstaract Nanocrystalline hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. Effects of precipitation temperature and different calcium to phosphate ratios (Ca/P) on the obtained powders were investigated. Characterization of the powders was performed using XRD and FTIR spectra, scanning electron microscopy, and transmission electron microscopy. Increase in precipitatio...

While the mechanical properties of stoichiometric B2 β-phase NiAl are well established, effect off-stoichiometric composition on fracture behavior has not yet been systematically studied over entire range 40-55% Al. Here we use microbending tests notched cantilever beams FIB-milled from single crystals with an aluminized as oxidation-induced gradient to determine influence Al concentration toug...

The importance of this work centers around four considerations. The above-mentioned alterations in the assay of Stubbs and Kamovsky may lead to the elucidation of principles not possible with less efficient and less accurate methods. A second consideration is the maintenance of resting CPM sufficiently above background levels in order to reflect actual phagocytizing/resting ratios. This may not...

We study the structure of non-stoichiometric HfOx films with variable composition using the methods of X-ray photoelectron spectroscopy and spectroscopic ellipsometry. HfOx, to a first approximation, is a mixture of HfO2 and Hf metal with a small amount ( 10–15%) of hafnium sub-oxides HfOy (y < 2). Spatial potential fluctuations, due to chemical compound fluctuations, lead to the percolation ch...

We report the development of different types of oxygen sensors based on yittria-stabilized zirconia (YSZ) as a solid electrolyte. The conventional oxygen sensor is a concentration cell with two porous Pt electrodes, one of which is exposed to air as a constant (reference) oxygen concentration and the other is exposed to automobile exhaust gas of variable oxygen concentration, depending on the a...

in this study, eutrophication was investigated in lake ontario to identify the interactions among effective drivers. the complexity of such phenomenon was modeled using a system dynamics approach based on a consideration of constant and variable stoichiometric ratios. the system dynamics approach is a powerful tool for developing object-oriented models to simulate complex phenomena that involve...

Discovering the organizational principles of genetic expression has recently become an arena of substantial investigative effort and modeling challenges. Laboratory findings of geneticists can be couched in terms of classes of stoichiometric networks that through stability analysis lead to classes of matrix patterns. In particular, targets, blocks, and decoys are variables in genetic systems wi...

For >20 years, the enigmatic behavior of plant mitochondrial genomes has been well described but not well understood. Chimeric genes appear, and occasionally are differentially replicated or expressed, with significant effects on plant phenotype, most notably on male fertility, yet the mechanisms of DNA replication, chimera formation, and recombination have remained elusive. Using mutations in ...

Mass action systems capture chemical reaction networks in homogeneous and dilute solutions. We suggest a notion of generalized mass action systems that admits arbitrary power-law rate functions and serves as a more realistic model for reaction networks in intracellular environments. In addition to the complexes of a network and the related stoichiometric subspace, we introduce corresponding kin...