Sources of elemental mercury (Hg0) include old natural gas regulators, manometers, sphygmomanometers, thermometers, and thermostats. Causes of Hg0 spills include improper storage, container breakage, children playing with Hg0, the breakage of devices containing Hg0, and ritualistic use of Hg0. Inhalation is the primary exposure route for Hg0. Mercury released into the environment can enter lake...

Why is the distribution of most chemicals not uniform within the ocean (Fig. 9.1)? In the absence of sources and sinks the effect of ocean circulation and mixing would be to smooth the distribution of chemicals. An important reason for nonuniformity is the increase in concentration that occurs in regions of evaporation, and the reduction in concentration that occurs in regions of rainfall or ri...

: a new fibrous adsorbent was prepared by grafting acrylic acid /acryl amide (aa/aam) co-monomers onto poly(ethylene terephtalat) (pet) fibers. the resulting sorbent has been characterized by fourier transform infrared spectroscopy (ft-ir), thermo gravimetric analysis (tga), scanning electron microscopy (sem) and elemental analysis and studied for the preconcentration and determination of trace...

the rheological properties of four different kuwaiti crude oils in the presence of polyacrylamide (paa) were investigated. paa was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. four different temperatures (25, 30, 35, and 40 °c) were used to evaluate different viscoelastic parameters of the treated and untreated kuw...

[no abstract available]

We explore the possibility for elemental analysis by NMR. To keep the efficiency of the signal acquisition common for all spin species, we propose to fix the frequency and vary the magnetic field to cover the isotopes involved in a sample. We introduce constant-frequency receptivity for quantitative elemental analysis in the frequency-fixed NMR experiment. Field-variable NMR experiments are dem...

transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

R. L. Verma, L. K. Sahu, Y. Kondo, N. Takegawa, S. Han, J. S. Jung, Y. J. Kim, S. Fan, N. Sugimoto, M. H. Shammaa, Y. H. Zhang, and Y. Zhao Research Center for Advanced Science and Technology, University of Tokyo, Tokyo, Japan Advanced Environmental Monitoring Research Center, Department of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju, Repub...

Elemental diet is as effective as corticosteroids in the treatment of previously untreated Crohn's disease. It is unclear whether a poor nutritional state is a prerequisite for efficacy of elemental diet, whether previously treated patients respond as well, or how duration of remission using elemental diet compares with corticosteroid induced remission. Forty two patients with active Crohn's di...